1. business and industrial
2. chemicals industry
3. plastics and polymers

LITHUANIAN ACADEMY OF SCIENCES
VILNIUS UNIVERSITY
INSTITUTE OF CHEMISTRY
10th INTERNATIONAL CONFERENCE OF LITHUANIAN
CHEMISTS
“CHEMISTRY 2011“
Dedicated to the International Year of Chemistry 2011
Abstracts
Vilnius
14-15 October, 2011
1
The abstracts were discussed and recomended for publishing by the
council of faculty of Chemistry of Vilnius University (28 september, 2011;
Protocol No. 87)
Scientific Committee
Prof. Valdemaras Razumas – Chairman
Prof. Zigmuntas Jonas Beresnevičius
Prof. Eugenijus Butkus
Prof. Aivaras Kareiva
Prof. Rimantas Ramanauskas
Organizing Committee
A. Kareiva – Chairman
R. Juškėnas
R. Makuška
A. Malinauskas
L. Mikoliūnaitė – Executive Secretary
E. Norkus
R. Ramanauskas
A. Ramanavičius
R. Raudonis
T. Subatniekienė
S. Tautkus
S. Tumkevičius
A. Valiūnienė (VU) – Scientific Secretary
ISBN 978-9955-634-65-2
2
CONTENTS
PLENARY LECTURES
Prof. Valdemaras Razumas, Opening and the speech of the president of the
Lithuanian academy of sciences.
Prof. Milos Nesladek, Surface chemistry driven luminescence in nanodiamond
particles: towards new in - cell operating biomolecular probes.
Prof. Jean-Luc Rehspringer, Towards new hard oxides magnets: how sol-gel
process can enchance solid state research.
Prof. Zineb Mekhalif, Organic nanofilms on metals and metal oxides surfaces.
Prof. Kenneth Warnmark, Tröger's base - the revival of an old molecule in
supramolecular chemistry.
Prof. Stefan Matile, Synthetic Biosupramolecules at Work: Photosystems, Sensors
and Ion Channels.
Prof. Sanjay Mathur, Synthetic Biosupramolecules at Work: Photosystems,
Sensors and Ion Channels.
Dr. Emmanuel Sinagra, Physicochemical Aspects of the Higher Order Structure of
Gelatin in Dilute Aqueous Solution.
Mr. Mervyn Richardson, The International Year of Chemistry - its Significance:
An Outline of the Services of The Royal Society of Chemistry, London.
10
12
13
14
15
16
17
18
POSTER SESSION
1.
2.
3.
4.
5.
6.
7.
8.
9.
L. Adamonytė, D. Tauraitė. SYNTHESIS OF GLYCEROL-1MONOOLEATE ANALOGUES
J. Aikaitė-Stanaitienė, M. Kavaliauskė, S. Grigiškis, E. V. Baškys, V.
Čipinytė. NEW SOIL REMEDIATION TECHNIQUE FOR CLEANING
SOILS CONTAMINATED WITH HEAVY HYDROCARBONS
E. Arbačiauskienė, W. Holzer, A. Šačkus. ETHYL-5-TRIFLYLOXY-1HPYRAZOLE-4-CARBOXYLATE: THE SYNTHESIS OF CONDENSED
PYRAZOLES VIA SONOGASHIRA AND SUZUKI REACTIONS
Milda Aštrauskaitė, R. Gruškienė, A. Veteikytė, I. Matijošytė.
BIOTECHNOLOGICAL ROUTE FOR THE SYNTHESIS OF POLYOLS
T.Ašmenavičius, L. Leonavičienė, A. Ramanavičius, R. Bradūnaitė, A.
Ramanavičienė, G.Kirdaitė, A.Vasiliauskas, Z.Mackiewicz. PRO/ANTIOXIDANT STATUS OF BLOOD SERUM OF RATS WITH
COLLAGEN ARTHRITIS BY USING GOLD NANOPARTICLES OF
VARIOUS SIZES
J. Bagdzevičienė, J. Kiuberis, R. Juškėnas*, S. Tautkus. SARCOPHAGUS
OF THE SINGER OF GOD AMON: INVESTIGATION OF THE
TECHNIQUE OF POLYCHROMY
S. Bagdzevicius, R. Grigalaitis, J. Banys, A. Sternberg, K. Bormanis.
BROADBAND
DIELECTRIC
INVESTIGATION
OF
SODIUM
POTASSIUM NIOBATE CERAMICS WITH 8% ANTIMONY
SUBSTITUTION
S. Bagdzevicius, R. Grigalaitis, J. Banys, A. Sternberg, K. Bormanis.
DIPOLAR GLASS-LIKE PEROVSKITE 0.8SrTiO3-0.2BiTiO3 CERAMICS
G. Bagdţiūnas, E. Butkus. SYNTHESIS OF DIASTEREOMERIC
19
20
21
22
23
24
25
26
27
3
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
BICYCLO[3.3.1]NONANE DIBENZOYL ESTERS AND THEIR
CHIROPTICAL PROPERTIES
A. Balčiūnaitė, A. Selskis, L. Tamašauskaitė-Tamašiūnaitė. SYNTHESIS,
CHARACTERIZATION
AND
INVESTIGATION
OF
ELECTROCATALYTIC ACTIVITY OF TITANIA NANOTUBE
SUPPORTED Au-Ni BIMETALLIC NANOPARTICLES
J. Baniukevič, J. Kirlytė, A. Ramanavičius, A. Kaušaitė-Minkštinienė, A.
Ramanavičienė. BOVINE LEUKEMIA VIRUS ANTIGEN-ANTIBODY
INTERACTION AFFINITY KINETIC EVALUATION
J. Barkauskas, J. Dakševič, I. Šakinytė. GRAPHITE OXIDATION
PRODUCTS: SYNTHESIS AND EXAMINATION
Bieliauskas A., Martynaitis V., Getautis V., Jankauskas V., Arlauskas K.,
Šačkus A. SYNTHESIS OF NEW HYDRAZONES POSSESSING
CARBAZOLE MOIETY AND THEIR OPTOELECTRONIC PROPERTIES
V. Bieliūnas, E. Orentas, S. Stončius. SYNTHESIS, ENANTIOMER
SEPARATION AND ABSOLUTE CONFIGURATION OF 9AZABICYCLO[3.3.1]NONANE DERIVATIVES
E. Borovikovaitė, J. Lukšėnienė, A. Selskis, J. Senvaitienė, R.
Ramanauskas, A. Kareiva. NEW METHOD FOR THE CONSERVATION
OF COPPER
G. Bubnienė, T. Malinauskas, M. Daškevičienė, V. Jankauskas, V.
Getautis. SYNTHESIS AND PROPERTIES OF POLYMERS POSSESSING
1,3OR
3,6-BIS(DIPHENYLETHENYL)
CARBAZOLYL
CHROMOPHORES
Vida Buinauskaitė, Sven Mangelinckx, Norbert De Kimpe, Algirdas
Šačkus. SYNTHESIS AND REDUCTIVE RING OPENING OF
SPIRO[BENZ[e]INDOLE-2,2’-PIPERIDIN]-6’-ONES
R. Butkienė, A. Judţentienė. J. Būdienė, A. Lugauskas. ACTIVITY OF
MARSH ROSEMARY ESSENTIAL OILS AGAINST MICROMYCETES
S. Butkutė, A. Zabiliūtė, A. Ţukauskas, G. Tamulaitis and A. Kareiva.
SOL-GEL SYNTHESIS AND CHARACTERIZATION OF GADOLINIUM
GALLIUM GARNETS (GGG)
R. Čekavičiūtė, D. Šimkūnaitė, A. Selskis, L. TamašauskaitėTamašiūnaitė. INVESTIGATION OF BOROHYDRIDE OXIDATION ON
TITANIA
NANOTUBE
SUPPORTED
Pt-Ni
BIMETALLIC
NANOPARTICLES
V.Černyšiov, M. Mauricas, I. Girkontaitė. THE ROLE OF MELATONIN
AND CIRCADIAN TIME ON THE MIGRATION OF LEUKOCYTES
INTO PERITONEAL CAVITY UPON IMMUNIZATION
R. Česūnienė, A. Gefenienė, D. Kaušpėdienė, A. Selskienė. COMBINED
REMOVAL OF AZO DYE AND COPPER(II) FROM AQUEOUS BINARY
SOLUTIONS
T. Charkova, O. Eicher-Lorka, A. Matijoška, Z. Kuodis, A. Rutavičius,
L. Labanauskas, G. Urbelis, R. Striela. THIOLIPIDS FOR MODELLING
TETHERED BILAYER LIPID MEMBRANES
O. Darčanova, B. Sivakova, A. Beganskienė, A. Kareiva. SOME
PREVENTIVE ANTIOXIDANTS STUDY FOR INK DAMAGED PAPER
J.Galkin, J.Pivoraite, A. Galkina ,E. Maţoniene, J. Liesiene. EFFECT OF
SURFACE ACTIVE COMPOUNDS ON GELATINIZATION, GELATION
AND GEL PROPERTIES OF STARCHES FROM DIFFERENT
28
29
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31
32
33
34
35
36
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38
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40
41
42
43
4
BOTANICAL SOURCES
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
E. Garskaite, T. Grande, M.-A. Einarsrud, S. Ciorba, B.S. Richards, M.
Lindgren, A .T. J. van Helvoort and E. Olsen. SYNTHESIS AND
PHOTOLUMINESCENT PROPERTIES OF RARE EARTH DOPED Al2O3
FOR SOLAR CELL APPLICATIONS
V. Gefenas, D. Bironaitė. SYNTHESIS AND ANTILEUKEMIC
ACTIVITY OF N- AND O-ETHOXYCARBONYLMETHYLATED
PYRIMIDINONES
I. Gerasimcik, I. Tolkaciova, T. Romaskevic, S. Budriene. SYNTHESIS
AND INVESTIGATION OF POLYURETHANE CAPSULES FROM
POLY(VINYL ALCOHOL) AND ISOPHORONE DIISOCYANATE
O. Girčienė, R. Ramanauskas, L. Gudavičiūtė, A. Martušienė. THE
INHIBITION EFFECT OF SODIUM NITRITE AND SILICATE ON STEEL
CORROSION
IN
CHLORIDE
CONTAMINATED
ALKALINE
SOLUTIONS
E. Graţėnaitė, J. Senvaitienė, J. Barkauskas. GRAPHITE OXIDE AND
GRAPHENE COATINGS ON METAL SURFACES
A. Grigucevičienė, P. Miečinskas, K. Leinartas, P. Kalinauskas, V.
Jasulaitienė, R. Juškėnas, L. Staišiūnas, E. Juzeliūnas. CORROSION OF
MAGNETRON SPUTTERED NANOCRYSTALLINE MG-CR ALLOYS IN
BORATE SOLUTIONS
I. Ignatjev, G. Niaura, E. Proniewicz, L.M. Proniewicz. PROBING OF
NEUROMEDIN B ADSORPTION ON SILVER, GOLD, AND COPPER
ELECTRODES BY SURFACE ENHANCED RAMAN SPECTROSCOPY
V. Intaitė, R. Vaickelionienė, V. Mickevičius, G. Mikulskienė.
SYNTHESIS AND CHARACTERIZATION OF AZOLES WITH
PYRROLIDINONE MOIETY
Maksim Ivanov, Kristina Klemkaite, Alexander Khinsky, Aivaras
Kareiva, Juras Banys. DIELECTRIC AND CONDUCTIVE PROPERTIES
OF HYDROTALCITE
V. Jakubkiene V. Linkus, I. Cikotiene. SYNTHESIS OF AMINO
SUBSTITUTED 5-NITROSOPYRIMIDINES
R. Jančienė, A. Vektarienė, A. Palaima, D. Podėnienė. EXPERIMENTAL
AND
COMPUTATIONAL
STUDY
OF
REDUCTIVE
NHETEROCYCLIZATION
OF
N-(2-NITROBENZOYL)-1,5BENZODIAZEPIN-2-ONES
A. Jankeviciute, I. Mohai, J. Szépvölgyi and A. Kareiva. RF THERMAL
PLASMA SYNTHESIS OF CORE – SHELL ALUMINA AMORPHOUS
CERAMICS NANOSIZED PARTICLES
V. Jasulaitienė, R.Kondrotas, R.Juškėnas, A.Selskis. THE INFLUENCE
OF ELECTRODEPOSITION CONDITIONS ON STRUCTURE AND
OPTICAL PROPERTIES OF ZNO FILMS
D. Jonkuvienė, J. Šalomskienė. EFFECT OF CHEMICAL FACTORS ON
THE GROWTH OF BACILLUS CEREUS IN MODEL FOOD MEDIA
J. Juodkazytė, B. Šebeka, S. Juodkazis, K. Juodkazis.
ELECTROCHEMISTRY OF HYDROGEN: H+2 ION AS MAIN
INTERMEDIATE IN REVERSIBLE HYDROGEN EVOLUTION AND
OXIDATION REACTIONS
44
45
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58
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46.
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48.
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51.
52.
53.
54.
55.
I. Jureviciute, A. Selskis, A. Malinauskas. THE EFFECT OF ANILINE
MONOMER COMPOUNDS STRUCTURE ON POLYMER FORMATION
AND REDOX PROPERTIES
J.Juršėnaitė,
D.
Characiejus.
CHANGES
OF
CD8+CD44h
LYMPHOCYTES DURING GROWTH OF SL2 TUMORS IN DBA/2 MICE
R. Juškėnas, V. Pakštas, A. Selskis, V. Karpavičienė, D. Aviţinis.
ELECTROCHEMICAL DEPOSITION OF ZnSe COATINGS AND THEIR
CHARACTERISATION
BY
STRUCTURAL
AND
PHOTOELECTROCHEMICAL METHODS
I. Kairytė, Z. Kuodis, A. Matijoška, O. Eicher-Lorka, G. Niaura. SERS
STUDY OF THE INTERACTION OF PERCHLORATE ANION WITH
POSITIVE CHARGE BEARING MERCAPTOHEXYLPYRIDINIUM
MONOLAYER ON GOLD ELECTRODE
Nerijus Karlonas, Almira Ramanavičienė, Arūnas Ramanavičius. HIGH
SENSITIVE ANALYSIS METHOD FOR THE DETERMINATION OF
ALPRAZOLAM,
MIDAZOLAM
AND
THEIR
α-HYDROXY
METABOLITES IN BLOOD, USING GAS CHROMATOGRAPHYNEGATIVE-ION CHEMICAL IONIZATION MASS SPECTROMETRY
(GC/NICI-MS)
A. Katelnikovas, A. Kareiva, and T. Jüstel. SYNTHESIS AND OPTICAL
PROPERTIES OF CaLu2Al4SiO12 DOPED BY Ce3+
D. Kaušpėdienė, E. Kazlauskienė, A. Selskienė, A. Gefenienė, R.
Butkienė. ANION EXCHANGE RESIN BEHAVIOR IN REMOVAL OF
DYE FROM AQUEOUS SOLUTIONS
Ieva Kazlauskaitė, Jurga Aleksejūnaitė, Rimantas Šiekštelė, Inga
Matijošytė. METAGENOMIC DNA AS THE OBJECT FOR THE NEW
BIO-CATALYSTS DISCOVERY
I. Kelpšaitė, S. Mockūnaitė, S. Ostachavičiūtė, A. Šulčiūtė, E. Valatka.
SYNTHESIS, STRUCTURE AND PHOTOCATALYTIC ACTIVITY OF
SOME MIXED METAL OXIDES
V. Kepenienė, E. Norkus, I. Stalnionienė and G. Stalnionis.
APPLICATION OF ENVIRONMENTALLY FRIENDLY LIGANDS FOR
ALKALINE
ELECTROLESS
COPPER
PLATING
SYSTEMS:
ELECTROLESS COPPER DEPOSITION USING ISOMERS OF 2,3HYDROXY-1,4-BUTANDICARBOXYLIC ACID AS CU(II) LIGANDS
Vilma Keršulytė, Aušra Valiūnienė. ELECTROCHEMICAL OXIDATION
OF CYANIDE
J. Kirlyte, P. Nadal, T. Mairal, V. Beni, A. Kausaite-Minkstimiene, C.K.
O’Sullivan. APTASENSORS FOR ALLERGEN LUPIN DETECTION
Edita Kleinaitė, R. Gruškienė, R. Beliūnas, I. Matijošytė, B. Tvaska, S.
Grigiškis, E. V. Baškys, M. Kavaliauskė. ENZYMATIC SYNTHESIS OF
2-ETHYLHEXYL OLEATE
L. Kosychova, G. Mikulskienė, R. Vidţiūnaitė, I. Bratkovskaja. A
CONVENIENT SYNTHESIS AND PROPERTIES OF NIVEL 5,6DIHYDRO-4H-TETRAZOLO-[1,5-a][1,5]BENZODIAZEPINE
DERIVATIVES
Svetlana Kozlovskaja, Gintaras Baltrūnas, Albertas Malinauskas.
ELECTROCHEMICAL RESPONSE OF SOME ANALYTES AT
POLYANILINE-COATED PLATINUM ELECTRODE: A COMPARATIVE
STUDY
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V. Kriščiūnienė, J. Rousseau, A. Šačkus, P. Rollin, A. Tatibouët, A.
Šačkus.
ULLMANN-TYPE
N-ARYLATION
OF
3AMINOBENZO[b]THIOPHENES
T. Krivorotova, A. Vareikis, R. Makuška. IS THE COMPOSITION OF
THE BRUSH COPOLYMERS AFFECTED BY THE RAFT PROCESS?
G. Krucaite, D. Mazetyte, V. Jankauskas, S. Grigalevicius. ARYLSUBSTITUTED CARBAZOLES AS MATERIALS FOR HOLE
TRANSPORTING LAYERS
J. Latynis, J. Barauskas. HYDRATION OF CYTOCHROME C STUDIED
BY FTIR SPECTROSCOPY AND DSC
I. Mačionienė, J. Šalomskienė, J. Puišo, T. Leiliūnas, A. Guobienė.
ANTIMICROBIAL ACTIVITY OF SILVER NANOPARTICLES
SYNTHESIZED BY CAMELIA SINENSIS LEAF EXTRACTS
R. Mašaraitė, J. Petraitis, I. Jarmalaitė, E. Naujalis. DETERMINATION
OF
DIBENZO-P-DIOXINS,
DIBENZOFURANS
AND
DIOXIN-LIKE PCB‘S IN FISH AND MEAT IN LITHUANIA
Viktorija Medelienė, Marija Kurtinaitienė. ELECTRODEPOSITION OF
Cu-Cr COATING IN THE ACIDIC COPER ELECTROLYTE WITH
METALLIC POWDER OF CHROMIUM
L. Mikalauskaitė, V. Krylova, R. Alaburdaitė, D. Milašienė. CONTACT
ANGLE MEASUREMENTS OF POLYPROPYLENE MODIFIED BY Ag2S
LAYERS
B. Miliauskaite, A. Jankauskas, J. Sataite, I. Zaikauskiene, I. Jarmalaite,
J. Petraitis. DETERMINATION OF CADMIUM IN FOOD OF ANIMAL
ORIGIN BY GRAPHITE FURNACE ATOMIC ABSORPTION
SPECTROMETRY
M. Misevičius, G. Degutis, I. Grigoravičiūtė-Puronienė, A. Kareiva.
PREPARATION
AND
CHARACTERIZATION
OF
VARIOUS
STRONTIUM ALUMINATES
A. Orentienė, V. Olšauskaitė, A. Padarauskas. INVESTIGATION AND
APPLICATION OF IMIDAZOLIUM-BASED IONIC LIQUIDS IN
CAPILLARY ELECTROPHORESIS
J.Petraitis, I.Jarmalaitė, V.Vaičiūnas. FORTY YEARS OF MONITORING
OF PESTICIDE RESIDUES IN LITHUANIA
O. Petrauskaite, V. Vitkauskas, J. Liesiene, A. Stumbras, J. Maminskas,
G. Juodzbalys. CELLULOSE/HYDROXYAPATITE COMPOSITES FOR
BONE TISSUE ENGINEERING
J. Pilipavičius, D. Sakalauskas, A. Beganskienė, A. Kareiva.
FABRICATION OF CARBON NANOTUBES AND COLLOIDAL SILICA
COMPOSITES VIA SOL-GEL PROCESS
A. Prichodko, E. Janėnaitė, V. Vičkačkaitė. DISPERSIVE LIQUIDLIQUID MICROEXTRACTION OF DERIVATIZED PARABENS
B. Rakovska, A. Malinauskas, A. Valiūnienė. THE ELECTROCHEMICAL
POLYMERIZATION OF ANILINE ON TITANIUM AND TITANIUM
DIOXIDE
R. Ramanauskas, R. Tarozaitė, A. Selskis, A. Grigucevičienė, A.
Kosenko, J. Juodkazytė. BLACK PAD PHENOMENON FOUND AFTER
THE ELECTROLESS Ni IMMERSION Au PROCESS
I. Razmislevičienė, V. Olšauskaitė, A. Padarauskas. IONIC LIQUIDBASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION: A
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89.
COMPARATIVE STUDY
J. Razumienė, I. Šakinytė, J. Barkauskas, V. Gurevičienė, R. Baronas.
CARBON
NANOMATERIALS
FOR
ELECTROCHEMICAL
BIOCATALYSIS
J. Razumienė, V. Gurevičienė, E. Čirbaitė, D. Tauraitė, R. Jančienė, A.
Palaima, R. Meškys, V. Razumas. NEW MEDIATORS FOR
BIOELECTROCATALYSIS
M. Ruzgytė, A. Beganskienė, V. Karabanovas, A. Selskis, A. Kareiva.
SYNTHESIS AND CHARACTERISATION OF LANTHANIDE DOPED
CADMIUM SELENIDE NANOPARTICLES
D. Sakalauskas, J. Pilipavičius, A. Beganskienė, A. Kareiva.
TMSPM/SILICA AND GLYMO/SILICA HYBRID ANTIREFLECTIVE
COATINGS FOR LASER SYSTEMS
O. Scit, I. Bogdanoviciene, E. Garskaite, R. Ramanauskas, E. Olsen, A.
Kareiva. ZINC DOPING EFFECTS IN SOL-GEL DERIVED CALCIUM
HYDROXYAPATITE POWDERS AND FILMS
B. Šebeka, I. Savickaja, J. Juodkazytė, A. Selskis. FORMATION AND
CHARACTERIZATION OF SPRAY PYROLYSED TRANSPARENT
CONDUCTIVE FLUORINE-DOPED TIN OXIDE FILMS
D. Sinkevičiūtė, N. Dukštienė. PHOTOELECTROCHEMISTRY OF
MoO2|SnO2|GLASS ELECTRODE IN AQUEOUS SOLUTIONS
Ramunas Skaudzius, Aivaras Kareiva.
MATRIX INDUCED
DIFFERENCES IN LUMINESCENCE PROPERTIES OF LANTHANIDEDOPED OR LANTHANIDE-SUBSTITUTED MIXED-METAL GARNETS
SYNTHESIZED BY SOL-GEL METHOD
E. Slaninaitė, V. Mickevičius, G. Mikulskienė. PRODUCTS
CYCLIZATION OF 2-{[1-(4-METHOXYPHENYL)-5-OXOPYRROLIDIN3-YL]CARBONYL}HYDRAZINECARBOX(THIO)AMIDES
Vaida Šmitienė, Vida Vičkačkaitė. DETERMINATION OF ORGANOTIN
COMPOUNDS IN WATER USING GC-MS WITH SELECTED ION
RECORDING
L. Staišiūnas, A.Grigucevičienė, K. Leinartas, P. Miečinskas, R.Juškėnas,
P. Kalinauskas, E. Juzeliūnas. ELECTROCHEMICAL
CHARACTERIZATION OF SPUTTER-DEPOSITED Mg-Nb ALLOYS
I. Stankevičienė, A. Jagminienė, E. Norkus, K. Prušinskas. Cu(II)
COMPLEX FORMATION WITH PENTAETHYLENEHEXAMINEDETERMINATION OF STABILITY CONSTANTS USING THE LIGAND
DISPLACEMENT METHOD
Ţ. Stankevičiūtė, A. Jančauskaitė, V. Gefenas. SYNTHESIS OF
PYRIMIDINE DERIVATIVES BY SONICATION AND TRADITIONAL
HEATING METHODS
S. Stončius, A. Neniškis. SYNTHESIS, STRUCTURAL AND CIRCULAR
DICHROISM STUDY OF SOME EXOCYCLIC BENZYLIDENE
SUBSTITUTED BICYCLONONANES
Judita Sukyte. ON ACID DECOMPOSITION OF SELENO – AND
TELLUROPENTATHIONATES
S. Survilienė, A. Češūnienė, A. Selskis, R. Butkienė, I. Jurevičūtė.
ELECTRODEPOSITION OF CrNi ALLOYS FROM AQUEOUS
OXALATE BATH
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103.
Š. Svirskas, M. Ivanov, Š. Bagdzevičius, J. Banys, M. Dunce, M.
Antonova, E. Birks, A. Sternberg, V.Zauls. DIELECTRIC PROPERTIES
OF 0.4Na1/2Bi1/2TiO3 – (0.6 – x)SrTiO3 - xPbTiO3 SOLID SOLUTIONS
A. Šaikūnas, J. Šarlauskas, Ţ. Anusevičius, L. Misevičienė, K.
Krikštopaitis, A. Marozienė, V.
Miliukienė and N. Čėnas.
ELECTROCHEMICAL AND ENZYMATIC REDUCTION OF
BENZOFUROXAN DERIVATIVES
D.Tauraitė, M. Morkūnas, M. E. Maier. SYNTHESIS OF Hsp90
CHAPERONE INHIBITORS
J. Trinkunaite-Felsen, A. Zalga, A. Kareiva. CHARACTERIZATION
AND SUGGESTED USAGE IN FOOD INDUSTRY OF NATURALLY
DERIVED CALCIUM COMPOUNDS
I. Tumosienė, K. Kantminienė, Z. J. Beresnevičius. REACTION
PRODUCTS
OF
3-[(4-METHYLPHENYL)AMINO]
PROPANOHYDRAZIDE WITH ARYL ISOCYANATES AND THEIR
TRANSFORMATIONS
M. Urbaitytė, A. Beganskienė, I. Bubinienė, J. Lukšėnienė.
INVESTIGATION OF FUNGISTATIC PROPERTIES OF PAPERS
TREATED WITH BROMOSEPT 50 OR P-3 TRIQUART COMPOUNDS
R. V. Urbonas, V. Poskus, J. Dodonova, S. Tumkevicius. SYNTHESIS OF
4,7-DIARYL-2-METHYLTHIO-7H-PYRROLO[2,3-d]PYRIMIDINES BY
THE SUZUKI COUPLING AND N-ARYLATION REACTIONS
S. Urnikaite, T. Malinauskas, V. Gaidelis, V. Jankauskas, V. Getautis.
PROCESSABLE AMBIPOLAR FULLERENE[60]-ARYLHYDRAZONE
DYADS
V.Vaičiūnas, R. Golubevas, J.Petraitis, I.Jarmalaitė. MONITORING OF
PESTICIDE RESIDUES IN 2009
T.Vengris,
R.Binkienė,
R.Butkienė,
R.Ragauskas,
A.Stončius.
TREATMENT OF WATER-BASED PAINT WASTEWATER WITH
FENTON PROCESS
C. Visnevskij, A. Baceviciute, R. Makuska. SYNTHESIS OF WATER
SOLUBLE CATIONIC MOLECULAR BRUSHES
S. Višniakova, A. Ţilinskas. THE SYNTHESIS OF PURPOSIVE
PHENANTHROLINIUM SALTS
A. Voitechovicius, K. Karpavicius, P. Adomenas, S. Tumkevicius.
SYNTHESIS OF NOVEL 6-SUBSTITUTED-2,4-DIARYLAND 4,6-DISUBSTITUTED 2-METHYLTHIOPYRIMIDINES
A. Ţielienė, L. Tamašauskaitė-Tamašiūnaitė, L. Naruškevičius, B.
Šimkūnaitė-Stanynienė, A. Sudavičius, V. Pakštas. EQCN STUDY OF
ELECTROCHEMICAL MODIFICATION OF BISMUTH SULFIDE FILMS
IN THE Co2+ CONTAINING ELECTROLYTE
108
109
110
111
112
113
114
115
116
117
118
119
120
121
9
International Session on Nanomaterials:
fabrication, characterisation and applications
ORAL PRESENTATIONS
L. Picco, R. Harniman, M. Antognozzi, A. Ulcinas, O. Payton, D. Engledew, D. Carberry,
D.B. Phillips, J. Grieve, J. Vicary, 1M. Padgett, M.J. Miles, BREAKING THE SPEED
LIMIT IN AN AFM- WITH A LIGHT TOUCH.
J.K.H. Hoerber, COMBINING SCANNING PROBE AND OPTICAL
MICROSCOPY TECHNIQUES
K. Grigoras, EFFECT OF ANNEALING ON THE ELECTRICAL
CHARACTERISTICS OF CNT BASED TRANSISTORS WITH ALUMINA
COATING
B. A. Snopok, SURFACE PLASMON RESONANCE AT THE NANOSCALE:
HOW DOES THAT WORK?
T. McMaster, AFM MAPPING OF BIOMOLECULAR FORCE AND SURFACE
INTERACTIONS: APPLICATIONS IN BIOLOGY AND GEOCHEMISTRY
V. Snitka, SURFACE CHEMISTRY MAPPING WITH TIP-ENHANCED RAMAN
MICROSCOPY
123
124
125
126
127
128
A. Ulčinas, G. Valdre, V. Snitka, M. J. Miles, P. M. Claesson, and M. AntognozzI,
FEELING THE SQUEEZE: SHEAR VISCOELASTICITY OF NANOCONFINED
WATER
G. Scotti, M. Mäkinen,P. Kanninen, T. Kallio and S. Franssila, SILICON NANOGRASS
for improved galvanic contact to micro fuel cell gas diffusion layer
D. Naumenko, V. Snitka, H. Lipsanen, CHEMICAL IMAGING AND GRAPHENEENHANCED RAMAN SPECTROSCOPY OF TIO2 NANOPARTICLES
S. C. Minne, L. Mininni, A. Slade, S. Hu, J. Kindt, H. Stadler, and C. Su, HIGH SPEED,
HIGH THROUGHPUT, SPM IMAGING AND NANOMECHANICS
P. Dorozhkin, A. Shchokin, E. Kuznetsov, V. Bykov, I. Bykov, AFM-RAMAN-SNOM
AND TIP ENHANCED RAMAN STUDIES OF MODERN NANOSTRUCTURES
I. Bružaitė, D. Naumenko, V. Snitka, E. Servienė, INVESTIGATION OF
STRUCTURAL AND CHEMICAL CHANGES
IN SACCHAROMYCES
CEREVISIAE YEAST CELLS BY AFM AND RAMAN SPECTROSCOPY
129
130
131
132
133
134
POSTER SESSION
Ya. Pirko, I. Danylenko1, O.Kolomys, P. Smertenko, V.Strelchuk, Ya.B. Blume.
1.
2.
3.
4.
5.
SYNTHESIS OF SILVER NANOPARTICLES USING PHYTOEXTRACTS
FROM HIGHER PLANTS
P. M. Boltovets, S. A. Kravchenko, B. A. Snopok. FABRICATION OF
INTERFACIAL GOLD NANOSTRUCTURES BY SIZE-CONTROLLED
CHEMICAL ETCHING
S. A. Kravchenko, A. Shanzer, B. A. Snopok. FUNCTIONAL
ARCHITECTURES BASED ON GOLD NANOPARTICLES BOUND TO
THE SURFACE OF SILVER BY A COORDINATION BRIDGE
A. Štogrin, I. Bružaitė. SYNTHESIS OF NANO-CARBON BY THE
ELECTROCHEMICAL DEPOSITION IN LIQUID OF ALCOHOL
S. Komarovskaja, I. Bružaitė. THE INFLUENCE OF ZnO NANOPARTICLES
ON THE VIABILITY OF THE SACCHAROMYCES CEREVISIAE YEAST
CELLS
135
136
137
138
139
10
“ Toward novel nano-resolution label-free detection probes in
cells using Fluorescent Nanodiamond (FND)”
M. Nesladek1,,6 and V. Petrakova 2,3, F. Fendrych2, J. Kucka3, J. Stursa3, P. Cigler4, M.
Ledvina4, P. Kneppo1
1
Czech Technical University in Prague, Faculty of Biomedical Engineering, Sítná sq. 3105,
272 01 Kladno, Czech Republic
2
Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Prague 8, Czech
Republic
3
Institute of Nuclear Physics, Academy of Sciences of the Czech Republic, v.v.i, 250 68 Rez
near Prague, Czech Republic
4
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech
Republic, v.v.i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
6
IMOMEC division, IMEC, University Hasselt, B-3590 Diepenbeek, Belgium
Fluorescent Nanodiamond (FND) particles have recently attracted high attention due
to their unique biocompatibility and simple carbon surface chemistry for employing
FNDs for targeted drug delivery in cancer cells [1,2]. A unique characteristic of ND
particles is its stable fluorescence from engineered color centers (i.e. neutral NV0 or
negatively charged NV- nitrogen-vacancy) that makes FNDs interesting nano-tool for
stimulations tracking and detection of delivery events. Recently we have
demonstrated principles of this novel method for remote optical monitoring of
chemical processes in biological environment based on color changes from photoluminescent NV centers in FND [3,4]. This method can thus open up novel domain
for contactless high resolution intracellular monitoring using standard confocal
microscope working in the far field. This method is based on driving the NV
luminescence chemically, by alternating the surface chemical potential, by interacting
atoms and molecules with the FND surface. Due to the small FND size, the close
proximity of NV centre from the surface is influence by chemical potential of the
environment and leads to changes in the ND energetics and intermingling with the
electronic NV states. This allows construction of optical chemo-biosensors operating
in cells, visible in classical confocal microscopes. This phenomenon was
demonstrated oxidized and hydrogenated and fluorinated ND. Hydrogenation of NDs
leads to quenching of fluorescence related to negatively charged (NV-) centers and by
this way produces color shifts from NV- (636 nm) to neutral NV0 (575nm)
fluorescence. Though this effect, unlike the FRET (Förster resonance energy transfer)
is detectable even in larger diamond particles such as 50-80 nm size nm, based on
modeling the reduction of diamond size to 5-10 nm increases the magnitude of NV
color shift phenomena by size effects. By using the charge interaction arising from
molecular environment in the cells, FND fluorescence can be changed and make thus
particular molecular interaction/delivery event optically visible.
[1] K. Chow, Xue-Qing Zhang, Mark Chen, Robert Lam, Erik Robinson, Houjin Huang, Daniel
Schaffer, Eiji Osawa, Andrei Goga, and Dean Ho, Sci .Transl Med 9 March 2011,
[2 ]V . Petráková, M. Nesládek, A. Taylor, F. Fendrych, P. Cígler, M. Ledvina, J. Vacík, J.
Štursa, J. Kučka, Feature Article, and cover letter, JALA, Vol. 16, No. 5 , 2011.
11
Figure 1 : Confocal microscopy of FND nanoparticles in IC21 cell cutlures. Fluorescence at
575 nm, is related to NV0 color center whilst fluorescence at 636 nm is related to NVcharged centre. NV- fluorescence can be successfully quenched after hydrogen treatment and
shows large changes in NV-/NVo ratio compared to termination by oxygen and fluorine.
12
Towards new hard oxides magnets : how sol-gel process can enhance solid state
research.
Petr Brázda; D. Niznansky; J.L. Rehspringer
IPCMS UMR 7504 CNRS Université de Strasbourg, France
Department of Inorganic Chemistry, Faculty of Science, Charles University, Prague
In each area of everyday life like work or leisure time activities, new materials are needed.
Computer memories or hard drives, self-cleaning windows or fabrics with waterproof or anti-bacterial
properties are some of the possible examples. This need is satisfied by materials research and discover
of new properties of compounds synthesized by chemist.
One area of new materials deals with materials in form of nano-scale objects. Preparation of
those is the challenge that material scientists take up either by physical ways like laser ablation or
molecular beam epitaxy or chemical ones.
Tailoring the properties of materials by chemistry require suitable chemical methods such as
sol-gel process. When compared to classical ceramic methods, sol-gel process usually needs lower
temperatures for preparation of desired phases and the material produced is far more homogenous than
if it would be prepared by some of the milling techniques or other solid state reactions.
One way to prepare nanosized materials is to prepare is a composite material where the
matrix material drive the growth of included nano material.
Our works deals since more than ten years with preparation of elusive form of iron
oxide, named -Fe2O3, and derivative magnetic compounds using sol-gel silica matrix composite
material.
-Fe2O3 is isomorphous with -Al2O3, AlFeO3 and GaFeO3. Iron atoms occupy four different
sites, three of them are octahedrally and one is tetrahedrally coordinated contrary to well-known
polymorph - the maghemite -Fe2O3 where iron occupy only two different sites, one octahedral and the
second tetrahedral.
The four particular crystallographic position of iron correspond to four magnetic sublattices
antiferomagnetically coupled by pairs with an overall non-zero magnetization attributed to a nonzero canting angle of antiparallel arrangement. It leads, in certain condition that we will described,
to a coercivity of 2 T at room temperature. This oxide therefore belongs to the oxide materials with
highest known coercivity at room temperature.
More interestingly we focuse our works on preparation of doped -Fe2O3 such as Al2-xFexO3 and
Ga2-yFeyO3, materials known as multiferroic when dopant content is in the range of 0.6 ≤ x ≤ 1.1
and 0.7 ≤ y ≤ 1.4. Again the sol-gel technique consisting in embodiment in amorphous SiO2 matrix
of iron and dopant atoms can leads to very pure and unexpected phases. We will show their unusual
properties and try to describe deeply the relationship between crystal structures and magnetic
properties.
13
ORGANIC NANOFILMS ON METALS AND METAL OXIDES SURFACES.
Prof. Zineb Mekhalif
Faculty of Chemistry, Namur University, Belgium
14
Tröger's base - the revival of an old molecule in supramolecular chemistry
Kenneth Wärnmark
Center for Analysis and Synthesis, Department of Chemistry, Lund University
P. O. Box 124, 22100 Lund, Sweden
E-mail: [email protected]
Tröger’s base1 (TB) (1) is a C2-symmetric molecule. Its chiral aromatic cavity makes it
potentially attractive for applications in the field of molecular recognition. The compound
was first synthesized 1887 by Julius Tröger, but its structure was determined much later. The
molecule was for a long time forgotten but has regained new interest due to synthetic
developments allowing for the synthesis of analogues, making it a building block in the field
of supramolecular chemistry. The synthetic development of TB analogues pursued by us2 and
others3 will be covered together with selected applications.
References
J. Tröger, J. Prakt. Chem. 1887, 36, 225–245.
Selected examples: a) J. Jensen, K. Wärnmark, Synthesis 2001, 1873–1877. b) J. Jensen, J. Teijler, K.
Wärnmark, J. Org. Chem. 2002, 67, 6008–6014. c) J. Jensen, M. Strozyk, K. Wärnmark, Synthesis 2002,
2761-2765 d) C. Solano, D. Svensson, Z. Olomi, J. Jensen, O. F. Wendt, K. Wärnmark, Eur. J. Org. Chem.
2005, 3510-3517. e) J. Artacho, K. Wärnmark, Synthesis 2009, 3120-3126.
3. Selected examples. a) M. Harmata, K. W. Carter, D. E. Jones, M. Kahraman, Tetrahedron Lett. 1996, 37,
6267-6270; b) M. Harmata, M. Kahraman, Tetrahedron: Asymmetry 2000, 11, 2875-2879. c) M.
Harmata, K.-O. Rayanil, C. L. Barnes, Supramol. Chem. 2006, 18, 581-586. d) U. Kiehne, A. Lützen,
Synthesis 2004, 1687-1695. e) D. Didier, S. Sergeyev, Eur. J. Org. Chem 2007, 3905–3910. f) M.
Faroughi, P. Jensen, A. C. Try, ARKIVOC 2009, 2, 269–280. g) A. Sharma, L. Guénée, J.-V. Naubron, J.
Lacour, Angew. Chem. Int. Ed. 2011, 50, 3677-3680.
1.
2.
15
SYNTHETIC BIOSUPRAMOLECULES AT WORK: PHOTOSYSTEMS, SENSORS AND
ION CHANNELS
Prof. Stefan Matile
University of Geneva, Switzerland
16
Chemistry at the Intersection of Materials Science, Physics and Biology
Sanjay Mathur
University of Cologne
Institute of Inorganic Chemistry
Chair, Inorganic and Materials Chemistry
Greinstraße 6
D-50939 Cologne, Germany
E-mail: [email protected]
Chemistry in the past few decades has played a major role in the convergence of life, physical
and engineering sciences leading not only to simple collaboration among the disciplines but to
a paradigm shift based on true disciplinary integration. Implications of chemistry as an
innovation motor are now visible for knowledge leap forward in various sectors such as
biomedical engineering, energy, health and security.
Chemical nano-sciences enabling controllable manipulation of matter at molecular length
scale have become fundamental generators for innovations in materials processing. The
successful synthesis, modification and assembly of nanobuilding units such as nanocrystals, wires and –tubes of different materials have demonstrated the importance of chemical
influence in materials synthesis, and have generated great expectations for the future.
Inorganic nanostructures inherit promises for substantial improvements in materials
engineering mainly due to improved physical and mechanical properties resulting from the
reduction of microstructural features by two to three orders of magnitude, when compared to
current engineering materials. This talk will present how chemically grown and designed
nanoparticles, nanowires and nanocomposites of different metal oxides open up new vistas of
material properties, which can be transformed into advanced material technologies. The
examples will include application of superparamagnetic iron oxide nanoparticles for drug
delivery applications, vapour phase synthesis of nanowires and development of nanowire
based gas sensing devices.
References:
1. J. Pan, R. Ganesan, H. Shen, S. Mathur, J. Phys. Chem. C., 114, 2010, 8245.
2. L. S. Xiao, H. Shen, R. von Hagen, L. Belkoura, S. Mathur Chem. Comm., 46, 2010, 6509.
3. D. Zopes, R. von Hagen, R. Müller, R. Fiz, S. Mathur, Nanoscale, 2, 2010, 2091.
4. S. Mathur, R. Ruegamer, N. Donia, H. Shen, S. Barth J. Nanosci. Nanotechnol. 8, 2008, 2597.
5. S. Mathur, H. Shen, N. Donia, T. Ruegamer, V. Sivakov, U. Werner, J. Am. Chem. Soc., 129, 2007, 9746.
17
PHYSICOCHEMICAL ASPECTS OF THE HIGHER ORDER STRUCTURE
OF GELATIN IN DILUTE AQUEOUS SOLUTION
A. Aquilina, S. Aquilina, R. Cortis, C. Farrugia, E. Sinagra
Department of Chemistry, University of Malta, Msida MSD2080, Malta
E-mail: [email protected]
The conversion of collagen to gelatin results in a heterogeneous product with a broad
molecular weight profile (MWP). Addition of a non-solvent, such as ethanol, to gelatin
solutions gradually causes the Florey-Huggins solvent-protein interaction parameter to exceed
the critical value for the different molecular weight fractions, causing desolvation of the
polymer. When sufficient solvent molecules are removed, the gelatin molecules begin to
aggregate, resulting in phase separation, and forming a coacervate. Modification of the net
charge of the protein, by adjusting the solution pH to values ranging about the iso-electric
point (IEP), influences the degree of interaction between the different molecular weight
fractions, and hence the response of the protein to non-solvent.1
The objective of this work was to study the response of lime-cured gelatin to the non-solvent
ethanol under different conditions of pH and sodium chloride concentration. Dilute gelatin
solutions at pH’s of 3, 5, 7, 9 or 11 containing 0.2% w/w gelatin and increasing ethanol
concentrations (40 to 75% w/w) were incubated at 39°C. Similar mixtures containing 0.1, 0.5
or 0.9% w/v NaCl were also prepared. The turbidity of the solution was measured at 600 nm
using a UV/Vis spectrophotometer. The role of salt in influencing the response of gelatin to
ethanol was also investigated by analysing the MWP of gelatin-salt mixtures using high
pressure size exclusion chromatography.
The behaviour of gelatin solutions with no added salt was observed to be dependent on pH.
Gelatin solutions adjusted to pH 3 and 11 were insensitive to the desolvating effect of ethanol,
while solutions adjusted to pH 5, 7 and 9 exhibited increased turbidity with increasing ethanol
concentration, the solutions at pH 5 being the most sensitive. The effect of added NaCl altered
the behaviour of gelatin solutions towards ethanol; gelatin solutions adjusted to pH’s 3 and 11
exhibited slight precipitation of gelatin. The opposite effect was observed for gelatin solutions
adjusted to pH’s 5, 7 and 9, which became less sensitive to increasing ethanol concentration
with increasing ionic strength of the system. The MWP of gelatin was greatly influenced by
the presence of salt, which resulted in a clear decrease in molecular weight, as evidenced by
the shift towards longer retention times, compared to solutions where salt was absent.
In terms of the DLVO theory, gelatin solutions incubated at extremes of pH carry a net charge
that gives rise to intermolecular repulsive forces, providing an energy barrier inhibiting
aggregation. On the other hand, the proximity of pH 5 to the IEP of B-type gelatins ensured
that the gelatin molecules in solution carried a reduced net charge and the electrical double
layer surrounding each molecule was not efficient in inhibiting aggregation. The addition of
salt to the gelatin solutions where the molecules carried a net charge caused a reduction of the
electrical double layer thickness, reducing the energy barrier to aggregation. In solutions
where the gelatin carries little or no net charge, the added salt caused dissociation of the
gelatin polymers to lower molecular weight species which are more soluble. This is thought to
occur by salt decreasing the range of influence of attractive intramolecular forces responsible
for protein folding.
References
1. C.A. Farrugia, M.J. Groves, J. Pharm. Pharmacol., 51 (1999) 643-649.
18
THE INTERNATIONAL YEAR OF CHEMISTRY - ITS SIGNIFICANCE: AN OUTLINE
OF THE SERVICES OF THE ROYAL SOCIETY OF CHEMISTRY, LONDON.
Mr. Mervyn Richardson
The Royal Society of Chemistry, United Kingdom
19
SYNTHESIS OF GLYCEROL-1-MONOOLEATE ANALOGUES
L. Adamonytė, D. Tauraitė
Institute of Biochemistry, Vilnius University, Mokslininkų 12,
LT-08662 Vilnius, Lithuania
E-mail: [email protected]
The monoolein-aqueous (MO) system, which is a thoroughly studied example of a
nanostructured system, forms a cubic phase that exists in excess with water. The bicontinuity
of the cubic pase makes it possible to solubilize both hydrophobic and hydrophilic
components. This means that lipophilic proteins like A-gliadin from wheat and
bacteriorhodopsin as well as relatively large amounts of membrane lipids and hydrophobic
compounds of biological relevance can be included. It is well known the use of MO for the
crystallization of proteins, especially of membrane proteins, that requires both the polar and
the apolar environments [1-2], also for molecular separation in gel electrophoresis medium
[3].
As the MO cubic phase system is so useful and significant, we have decided to try to
synthesise some analogues of monoolein expecting that new compounds not only could
organize cubic or other liquid phases, but also would characterize different important and
interesting features. So our purpose was to synthesize such compounds, in which fatty acid
would be connected not by ester bond as in the monoolein case, but by the amide bond.
Hence, one of basic reagents should be for instance, serinol (2-amino-1,3-propanediol), not
glycerol.
We have synthesized some new compounds using linoleic and oleic acids as well as 2amino-1,3-propanediol, 3-amino-1,2-propanediol and 1,3-diamino-2-propanol. Firstly, Nhydroxysuccinimide esters of fatty acids were the result of condensing acids with Nhydroxysuccinimide in the presence of dicyclohexylcarbodiimide. Later these esters have
been combined with 2-amino-1,3-propanediol, 3-amino-1,2-propanediol and 1,3-diamino-2propanol obtaining five new compounds as expected (Scheme 2). The structures of
synthesized compounds were proved by 1H and 13C NMR spectrum data.
O
OH
NOCOR
OH
NH2
OH
NH2
OH
NH2
OH
NH2
DMFA
25-30 oC
OH
OH
NHCOR
OH
NHCOR
OH
NHCOR
OH
NHCOR
O
R1 = (CH2)7CH=CH(CH2)7CH3
R2 = (CH2)7CH= CHCH2CH=CH(CH2)4CH3
References
1. J. Barauskas, T. Nylander, In Delivery and controlled release of bioactives in foods and nutraceuticals.
N. Garti, Ed. Woodhead Publishing Ltd: Cambridge, 2008, 107.
2. J.P. Neves Silva, M.E.C.D. Real Oliveira, P.J.G. Coutinho, J. Photochem. Photobiol. A:Chemistry, 203
(2009) 32–39.
3. N. Carlsson, N. Sanandaji, M. Voinova, B. Akerman, Langmuir, 22 (2006) 4408–4414.
20
NEW SOIL REMEDIATION TECHNIQUE FOR CLEANING SOILS
CONTAMINATED WITH HEAVY HYDROCARBONS
J. Aikaitė-Stanaitienė, M. Kavaliauskė, S. Grigiškis, E. V. Baškys, V. Čipinytė
JSC “Biocentras”, Graičiūno g. 10, 02241 Vilnius, Lithuania.
E-mail: [email protected]
Various human activities have already resulted in more than 3.5 millions sites across EU
being contaminated and the soil contaminated by oil pollutants represents more than a half of
overall affected sites [1]. Many of those sites are rendering otherwise valuable soil unusable.
A clear need exists to remediate these sites through effective solutions at a viable cost to
society. Preferably, in-situ techniques are applied to decontaminate such sites, because the
alternatives – ex-situ treatment or containment – are too expensive or socially poor solution.
However, the high contaminant concentrations especially in case of heavy hydrocarbon (HC)
mixtures and the low soil permeability are limiting application of available in-situ techniques.
In-situ techniques can only be enhanced by combining several soil remediation techniques
and improving the performance of these techniques.
Integrated techniques that affect different aspects of contaminant removal can improve
remediation of persistent HC from different kinds of soils. The high molecular weight
fractions are exceptionally hard to remediate [2]. Combining multiple techniques for
remediation of high initial concentrations of HC can overcome many of the limitations that
exist for individual technologies.
The achieved successes of newly created soil remediation technique are used three step of soil
cleaning (depending on the initial level of soil pollution it can be applied all three steps of soil
cleaning, or only the second and the third steps, or only the third step). 1st step – using of
SORBENT system (S-S) for collection HC contaminants, can be applied for soil treatment
when initial oil concentrations are up to 350 g/kg. It reduces the oil concentration to 220–
170 g/kg during 7–14 days. Then, the second step of SORBENT integrated technique can be
applied. Both sorbent and bio-surfactant (included in S-S composition) are environmentally
friendly thus no risk exist to cause secondary contamination. 2nd step – bacterial
bioremediation is the biodegradation of different kinds of oil in various soil profiles using
SORBENT bacterial preparation (SBP) and can be applied for soil treatment when residual oil
concentrations are 220–170 g/kg. It reduces the oil concentration to 50–20 g/kg during 6–
9 months. Mixed culture of the HC degrading bacteria has higher potential of heavy HC
biodegradation. However, high concentration of HC in soil can slow down the degradation
processes; reduction of HC amount by S-S will improve the biodegradation (biosurfactant
makes HC more bioavailable for the selected bacterial strains and higher level of HC removal
from soil can be achieved). 3rd step – phyto-remediation – the last stage of soil cleaning and
reclamation technique. Application of this stage – final stage of oil pollution clean-up phase,
which allows the full restoration of soil conditions.
This newly developed integrated SORBENT technique enables to achieve low soil pollution
by HC level (no more than 1-5 g/kg soil) regarding to the requirements of European standards
for soil clean up requirements depending on soils current use and approved future use.
Acknowledgments
This paper reflects findings from EU funded 7 th Framework program project “SORBENT” (232533).
References
1. Fingas Mervin. Oil spill science and technology. Elsevier Inc. 2011.
2. Singh, A.; Ward, O. P. Biodegradation and bioremediation. Canada: Springer, 2004. ISBN-3-540-21101-2.
21
ETHYL-5-TRIFLYLOXY-1H-PYRAZOLE-4-CARBOXYLATE: THE SYNTHESIS
OF CONDENSED PYRAZOLES VIA SONOGASHIRA AND SUZUKI REACTIONS
E. Arbačiauskienė, W. Holzer, A. Šačkus
Kaunas University of Technology, Department of Organic Chemistry, Radvilėnų pl. 19,
LT-50254 Kaunas, Lithuania
University of Vienna, Department of Drug and Natural Product Synthesis, Atlhanstrasse 14,
A-1090, Vienna, Austria
E-mail: [email protected]
The easily obtainable title compound ethyl 5-trifloyloxy-1H-pyrazole-4-carboxylate was used
as a precursor in Sonogashira-type cross-coupling reaction with various alkynes to obtain the
corresponding 5-alkynyl-4-carbethoxypyrazoles. Cyclization of the latter ortho-difunctional
synthons afforded different condensed pyrazoles such as pyrano[4,3-c]pyrazol-4(1H)-ones as
well as 1,5-dihydro-4H-pyrazolo[4,3-c]pyridin-4-ones. Suzuki coupling of triflate with
(subst.) phenylboronic acids gave the accordant 5-arylpyrazoles. Heating of 5-(3chlorophenyl)-1-phenyl-1H-pyrazole-4-carboxylic acid with trifluoromethanesulfonic acid led
to the formation of an unexpected tetracyclic system. Detailed NMR spectroscopic
investigations were undertaken with all obtained products.
Cl
O
N
O
OEt
X
N
N
N
O
Ph
OTf
R
N
N
Ph
X = O or NOH
22
BIOTECHNOLOGICAL ROUTE FOR THE SYNTHESIS OF POLYOLS
1
Milda Aštrauskaitė, R. Gruškienė, A. Veteikytė, I. Matijošytė *,
Vilnius university Institute of Biotechnology, Sector of Applied Biocatalysis,
V.A. Graičiūno str. 8-255, LT-02241, Vilnius, Lithuania,
*E-mail:[email protected]
Traditional bulk chemical manufacture abounds with classical "stoichiometric"
technologies that generate large amount of organic and mainly inorganic waste, needs
extraordinary high-cost process parameters (pressure, temperature) and is usually limited.
Conversely, enzyme technology (biocatalysis) has a lot of advantages over the conventional
methods. The introduction of biocatalytic reactions is well suited to cost reduction and higher
product quality products, as well as to more sustainable processes. The use of bio-based raw
materials for chemical synthesis, and the economy of molecular transformations like atom
economy and step economy are of growing importance [1]. As safety, health and
environmental issues are key drivers for process improvements in the chemical industry, the
development of biocatalytic reactions or pathways replacing hazardous reagents are a major
focus. However, until now only more than 150 biocatalytic processes has been industrialized
what is approximately 6 % of total industrial chemical processes [2]. We were aiming to
expand the use of enzymes for chemical processes by developing a green alternative to the
existing petrochemical-derived polyurethane foam (PU) by providing the chemo-enzymatic
reaction pathway for biomass-derived polyol production.
The investigation was focused on polyol synthesis derived from bio-based raw
material – vegetable oil. Commercially available biocatalyst – Novozyme 435 was applied as
a catalyst for both reaction steps and linoleic acid was used as co-catalyst (Scheme 1).
O
O
Vegetable oil
enzyme
linoleic acid, H2O2
O
O
C
O
C
O
O
O
O
O
C
OH
O
O
enzyme
H2O
C
O
O
C
O
O
C
OH
OH
OH
Scheme 1. Biotechnological route for the synthesis of polyol
Biotechnological pathway consists of two stages: epoxidation and hydrolysis
reactions. The reaction conditions were estimated for each reaction step separately:
temperature, amount of enzyme, linoleic acid and ratio of initial components. The epoxidation
reaction was followed spectrophotometrically using the method with picric acid, while
hydrolysis step was followed by using an automated titrator.
Whereas the commercial enzyme is in immobilized form the reusability test has
showed that enzyme could be applied for the reaction for more than 10 times without any loss
of activity.
The results will be presented in more detail during the conference at the poster
session.
References
1.
2.
R.A. Sheldon, Green Chem., 9 (2007) 1273-1283
R. Wohlgemuth, New Biotechnol., 25 (2009) 204-213
23
PRO-/ANTIOXIDANT STATUS OF BLOOD SERUM OF RATS WITH COLLAGEN
ARTHRITIS BY USING GOLD NANOPARTICLES OF VARIOUS SIZES
T.Ašmenavičius, L. Leonavičienė, A. Ramanavičius, R. Bradūnaitė, A. Ramanavičienė,
G.Kirdaitė, A.Vasiliauskas, Z.Mackiewicz
State Research Institute, Centre for Innovative Medicine, Zygimantu 9, 01102 Vilnius,
Lithuania
E-mail: [email protected]
An area of research, where it is thought that nanotechnology will have a profound impact,
is within medical science, and the discovering of therapeutic inorganic nanoparticles is a very
important field of nanomedicine. Gold nanoparticles (AuNPs) can be used in various
biomedical applications, however, very little is known about their effect in the treatment of
rheumatic diseases [1]. Although oxidative stress has been found to be associated with
inflammation and joint destruction, its role in inflammatory diseases is still unclear and the link
between AuNPs and oxidative stress is not well established [2]. The aim of the study was to
evaluate the pro-/antioxidant status of blood serum in the rats in early and chronic stages in
collagen-induced arthritis (CIA) treated by AuNPs of different size (13 nm and 50 nm). The
particle suspensions were sterilized under UV light for 1 d. Wistar male rats with CIA were
used for investigation of therapeutic and antioxidant activity of AuNPs, which were injected
intraarticularly (i.a.). Serum oxidative products such as malondialdehyde (MDA) and antioxidative enzyme catalase (CAT) were investigated.
nmol/ml
18
mmol/L/min
80
16
70
14
60
12
10
8
6
*
50
I Control
40
II 13 nm AuNPs
30
III 50 nm AuNPs
4
20
2
10
0
*
0
MDA
Catalase
Fig.1. Pro-/antioxidant indices in serum of rats with established collagen-induced arthritis treated by
gold nanoparticles (AuNPs) of various sizes.
Data shown represent mean values SEM, n = 8 (number of animals in each group). Two groups of animals
since day 13 received the treatment with 13 nm (II group) and 50 nm (III group) AuNPs. The control group (I)
was injected i.a. with the same dose of saline solution. The total number of injections was 12. * – The
differences are significant in comparison with the control group.
Conclusions. No significant induction of oxidative stress due to the AuNPs was observed. The
results obtained disclose the effectual role of AuNPs as an anti-inflammatory and antioxidative agent generated the increased activity of anti-oxidant enzyme CAT and decrease of
MDA level in blood serum of rats with CIA.
References
1. Tsai CY, Shiau AL, Chen SY, Chen YH, Cheng PC, Chang MY, et al. Arthritis Rheum 2007; 56(2): 544-54.
2. Brandenberger C, Rothen-Rutishauser B, Mühlfeld C, Schmid O, Ferron GA, Maier KL, et al. Toxicol Appl
Pharmacol 2010; 242(1): 56-65.
Acknowledgements. This research was funded by a grant (No. MIP-74/2010) received from the Research Council
of Lithuania.
24
SARCOPHAGUS OF THE SINGER OF GOD AMON:
INVESTIGATION OF THE TECHNIQUE OF POLYCHROMY
J. Bagdzevičienė, J. Kiuberis, R. Juškėnas*, S. Tautkus
Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24,
LT-01535, Vilnius, Lithuania, E-mail: [email protected]
*Department of Materials Structure, Institute of Chemistry Center for Physical Sciences and
Technology, A. Goštauto 9, LT-01108 Vilnius, Lithuania
Lithuanian museums do not abound in art values of ancient Egypt. A larger collection
is stored in the National M. K. Čiurlionis Art Museum (296 items). The first professional
egyptologist in Lithuania historian Marija Rudzinskaitė-Arcimavičienė (1885–1941) enriched
the collection of the latter museum with especially valuable exhibits. In 1924 the scientist was
especially happy to have acquired a part of a sarcophagus with a mummy dated the 11 th–9th
century BC found in the environs of Luxor from the Cairo Museum. The sarcophagus was
acquired without a cover; it was amply painted with symbolic scenes and hieroglyphs. Having
deciphered the hieroglyphs the scientist established that it was the female mummy of a singer
of the Sun God Amon [1].
In 2008, specialists of Pranas Gudynas Restoration Centre started to examine the
sarcophagus of a singer of God Amon (Ancient Egypt, Thebes, 11th–9th century BC; Ficus
sycomorus wood, polychromy; 27 x 192 x 50 cm) with great interest and responsibility, later
the conservation method of the exhibit was chosen. By combining the analytical methods
(microchemical, optical microscopy, FTIR and XRD)
polychromy materials were
determined, the ground and pigments were identified and the structure of painting layers was
described, technological peculiarities of the work were characterised.
Having carried out a microchemical qualitative analysis, FTIR and XRD analyses it
was established that the ground consisted of two layers: gypsum, chalk, clay, charcoal and
filaments of vegetable fibre were found in the lower layer of the ground; the upper layer of
the ground contained gypsum, chalk, clay and sand. Having carried out morphological studies
of the vegetable filaments discovered in the ground layer the species of the plant was
impossible to identify. However, the comparison of the IR spectra of the filaments and the
papyrus enabled the supposition to be made that this could be the fibre of papyrus Cyperus
papyrus. Paint of six colours – white, yellow, red, blue, green and black – was used for
polychromy of the sarcophagus. Pure colours were used and the principle of multilayered
painting was applied. Pigments of Egyptian blue, huntite, the yellow and red ochres, green
earth and charcoal were identified. Having carried out FTIR analysis it was established that
the binding agent of both layers of the ground and paint was gum arabic.
The microchemical qualitative, stratigraphic, FTIR and XRD analyses of the
composition of the ground, pigments of the paint samples and the binding agent carried out
enabled the polychromy technique to be characterised. It is obvious that the substances
identified correspond to the substances used by the Egyptians [2, 3]. The research results
helped choose the consolidating agents optimally and apply a new conservation method.
References
1. A. Snitkuvienė, Kultūros barai, 8 (1985) 63–65.
2. M.Uda, In: X-rays for Archaeology. The Netherlands: Springer, 1 (2005) 3–26.
3. J. Riederer, Artist s Pigments: A Handbook of their History and Characteristics; Ed. E. West Fitzhugh,
National Galery of Art, Washington, vol. III (1997) 23–45.
25
BROADBAND DIELECTRIC INVESTIGATION OF SODIUM POTASSIUM
NIOBATE CERAMICS WITH 8% ANTIMONY SUBSTITUTION
S. Bagdzevicius1, R. Grigalaitis1, J. Banys1, A. Sternberg2, K. Bormanis2
Faculty of Physic, Vilnius University, Sauletekis str. 9/3, 10222 Vilnius, Lithuania
2
Institute of Solid State Physic, University of Latvia, Kengaraga str. 8, 1063 Riga, Latvia
E-mail: [email protected]
1
Lead containing ceramics like Pb(ZrxTi1-x)O3 (PZT) or Pb(Mg1/3Nb2/3)O3 (PMN) have
excellent piezoelectric properties and are widely used in sensors, transducers and other micro
and macro electromechanical devices. However it is desirable to use lead-free materials for
environmental protection, lead-containing materials should be replaced with lead-free
materials [1]. One of such ceramic potentially could be sodium potassium niobate KxNa1-x
NbO3 (KNN) near morphotropic phase boundary (MPB) which is at about 50% K and 50%
Na for KNN. The main problem with KNN is sintering: it is difficult to obtain well-sintered
KNN ceramic using an ordinary sintering process because of the high volatility of alkaline
elements at high temperatures [2].
In this work we present dielectric permittivity results of KNN ceramics doped antimony
(K0.5Na0.5)(Nb0.92Sb0.08)O3 with sintering aid MnO2 (0.5 mol. % MnO2). Its dielectric
properties was investigated in broad frequency (from 20 Hz to 35 GHz) and temperature
(from 125 K to 500 K) range.
Above room temperature obtained results
3000
shows two phase transitions at T= 538 K
5 kHz
2500
35 kHz
and T=385 K which could be attributed to
1 MHz
2000
phase transitions from paraelectric cubic
100 MHz
'
into ferroelectric tetragonal state and from
1500
2.5 GHz
tetragonal into orthorhombic state because
9 GHz
1000
30 GHz
in undoped K0.5Na0.5NbO3 ceramics it was
observed the same sequence of transitions
500
with Tc=677 K and TT-O=464 K respectively
0
[3]. Partial substitution of Nb+5 ions with
100 200 300 400 500 600
Sb+5 lowers both of these phase transitions
T [K]
temperatures compared to undoped KNN Figure 1 Temperature dependence of dielectric
ceramics.
Below
room
temperature
permittivity of (K0.5Na0.5)(Nb0.92Sb0.02)O3
investigation revealed one more dielectric
ceramic at fixed frequencies.
permittivity dispersion, which could be
attributed to diffused phase transition corresponding to phase transition in pure KNN from
orthorhombic into rhombohedral ferroelectric state at TO-R=165 K [3]. Below 165 K there is a
dielectric dispersion which is similar to the relaxor ferroelectric from the real part of dielectric
permittivity frequency dependence, what is confirmed by linear dependence of dielectric
losses.
References
1. Council Epat, Directive 2002/95/EC of the European parliament and of the council of January 2003 on the
restriction of the use of hazardous substances in electrical and electronic equipment. Eur. J., 37, 19 (2003).
2. M. Dambekalne, M. Antonova, M. Livinsh, A. Kalvane, A. Mishnov, I. Smeltere, R. Krutokhvostov, K.
Bormanis, A. Sternberg, Integrated Ferroelectrics 102 (1) 52-61 (2008).
3. E. Buixaderas, V. Bovtun, M. Kempa, M. Savinov, D. Nuzhnyy, F. Kadlec, P. Vanek, J. Petzelt, M. Eriksson
and Z. Shen, J. Appl. Phys. 107, 014111 (2010).
26
DIPOLAR GLASS-LIKE PEROVSKITE 0.8SrTiO3-0.2BiTiO3 CERAMICS
S. Bagdzevicius1, R. Grigalaitis1, J. Banys1, A. Sternberg2, K. Bormanis2
Faculty of Physic, Vilnius University, Sauletekis str. 9/3, 10222 Vilnius, Lithuania
2
Institute of Solid State Physic, University of Latvia, Kengaraga str. 8, 1063 Riga, Latvia
E-mail: [email protected]
1
Lead containing piezoelectric ceramics and single crystals has been widely used as actuator,
transducer, and sensor materials. However, the toxicity of lead oxide has led to a demand for
alternative materials that are more environment friendly. Strontium Bismuth Titanate (SBT) is
the one of such compounds.
It is well known that in pure incipient ferroelectrics, like KTaO3 or SrTiO3 polar phonons are
responsible for the dielectric permittivity and no pronounced dielectric dispersion is observed
below the soft-mode response [1]. The ferroelectricity in such materials can be induced by
application of strong enough electric field, uniaxial stress or substitution of A-site ions by
isovalent or heterovalent ions. The broadband dielectric studies on SBT ceramics (up to
x 0.13) [2] showed that Bi doping induces formation of local antiferrodistortive and polar
regions. This causes a complex relaxational dynamics below the phonon frequency range.
Because no broadband dielectric studies (on our knowledge) have been carried out for SBT
with bigger Bismuth content, the aim of this work was to extend the investigations of
dielectric dispersion in SBT toward x=0.2.
The dielectric properties of 0.8SrTiO3-0.2BiTiO3 ceramics have been investigated from 20 Hz
to GHz range. Obtained results showed the pronounced dielectric dispersion which looks
similar to the one typically observed in disordered materials. In contrast to the proposals in
[2], which claimed that the dispersion SBT ceramics looks relaxor-like, we have to point its
close similarity to the dispersion typically found in dipolar glasses. The calculated distribution
of relaxation times f( ) confirms our findings because no splitting into two parts of f( ) can be
seen.
References
1. K.A. Muller and H. Burkard, Phys. Rev. B. 19, 3593 (1979).
2. V. Porokhonskyy et.al. Phys. Rev. B. 69, 144104 (2004).
27
SYNTHESIS OF DIASTEREOMERIC BICYCLO[3.3.1]NONANE DIBENZOYL
ESTERS AND THEIR CHIROPTICAL PROPERTIES
G. Bagdţiūnas, E. Butkus
Department of Organic Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius,
Lithuania
E-mail:[email protected]
Chiral molecules having two chromophores with strong electric-dipole allowed transitions
couple to each other (exciton coupling).[1] To study this phenomenon, relevant
dichromophoric molecular structures are required. Because of a proper molecular geometry
bridged bicyclic compounds are suitable model structures for studying chiroptical properties
and interaction between the non-conjugated chromophores. Herein we present the synthesis of
chiral diastereomeric bicyclo[3.3.1]nonane dibenzoyl esters 1-3 and the respective monoesters
4 and 5 (Fig. 1), and study of their CD spectra. The synthesis of the diasteromeric dibenzoates
was accomplished from the starting enantiomerically pure bicyclo[3.3.1]nonane-2,6-dione. [2]
Endo-configuration derivatives were obtained via carbonyl reduction and subsequent
esterification, inversion to the exo-configuration was achieved using Mitsunobu reaction.
Diendo ester 1
Diexo ester 2
Exoendo ester 3
Monoendo ester 4
Monoexo ester 5
1
15
2
2
10
5
X10
4
0
3
X10
-5
5
-10
-15
210
220
230
240
250
260
270
nm
Fig.1. The diastereomeric benzoates and the CD spectra
The Cotton Effect depends on the interchromophoric geometry and the rotational strength is
dependent on the distance between the chromophores and, in particular, on the appropriate
orientation of chromophores. The exo,endo-dibenzoate 3 showed a pair of typical excitonsplit Cotton effects with opposite signs centred upon the UV absorption (230 nm) of the
benzoate chromophore (Fig. 1). The directions of the 1La transitions and the C-O bonds are
approximately parallel to each other, at least in one of the conformations, and the sign of the
split CD curve reflects the predetermined absolute stereochemistry of the diol group in
starting molecule. The difference in intensity of the bands for both di-endo and di-exo
dibenzoates of the 1La transition was insignificant due to the analogous geometric orientation
of the chromophores in these structures. The analogous mono-benzoates 4,5 showed very
weak bands in the CD spectra confirming interchromophoric interactions.
References
1.
2.
(a) N. Berova, K. Nakanishi. Exciton chirality method: principles and application. In K. Nakanishi, N.
Berova, R.W. Woody, Eds, Circular Dichroism: Principles and Applications, 2nd ed. New York: WileyVCH; 2000. p. 337–382. (b) N. Berova, L. Di Bari, G. Pescitelli. Chem. Soc. Rev., 2007, 36, 914-931.
C. J. Wallentin, E. Orentas, E. Butkus, K. Warnmark. Synthesis, 2009, 864-867.
28
SYNTHESIS, CHARACTERIZATION AND INVESTIGATION OF
ELECTROCATALYTIC ACTIVITY OF TITANIA NANOTUBE SUPPORTED
Au-Ni BIMETALLIC NANOPARTICLES
A. Balčiūnaitė1,2, A. Selskis1, L. Tamašauskaitė-Tamašiūnaitė1
1
State Research Institute, Center for Physical Sciences and Technology, Savanorių pr.
231, LT-02300 Vilnius, Lithuania
2
Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania
E-mail: [email protected]
In the present work we report the optimization of the synthesis of titania nanotube
supported Au-Ni bimetallic nanoparticles catalysts (denoted as Au(Ni)/TiO2-NTs) by
galvanic displacement of electroless nickel layer. The catalysts were prepared by a threestep procedure: i) preparation of TiO2 nanotube arrays by anodization of titanium sheets
in an aqueous sulfuric acid solution containing some NH4F [1]; ii) deposition of an
electroless Ni sublayer on the synthesized TiO2 nanotube arrays and iii) subsequent
immersion of the Ni/TiO2-NTs electrode into the gold-containing solution. Due to
spontaneously occurring partial galvanic displacement of electroless Ni sublayer with Au
numerous nm-scaled gold particles were formed on the surface of titania nanotube. The
morphology and composition of the catalysts were identified using scanning electron
microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy.
The electrochemical behavior and electrocatalytic activity of the fabricated catalysts
towards borohydride oxidation were measured by means of cyclic voltammetry. The
electroactive area of gold surface created on fabricated catalysts was determined from
cyclic voltammograms of Au/TiO2-NTs electrodes recorded in a deaerated 0.5 M H2SO4
solution at a scan rate of 10 mV s-1.
The prepared nano-Au(Ni)/TiO2-NTs electrodes exhibited a high catalytic
efficiency towards the oxidation of borohydride when compared to that of bulk Au
electrode. A higher catalytic activity of prepared nano-Au(Ni)/TiO2-NTs electrodes under
various conditions may be related to production of smaller gold nanoparticles and their
fine and uniform dispersion on the surface.
The titania nanotube supported Au-Ni bimetallic nanoparticles catalysts seem to
be a promising anodic material for direct borohydride fuel cells.
Acknowledgement
This research was funded by a grant (No. ATE-03/2010) from the Research Council of
Lithuania. A. Balčiūnaitė also acknowledges Student Research Fellowship Award from
the Research Council of Lithuania. The authors are grateful A. Sudavičius for XPS
analysis.
References
1. T. Tian, X. Xiao, R. Liu, H. She, X. Hu. J. Mater. Sci. 42 (2007) 5539-5543.
29
BOVINE LEUKEMIA VIRUS ANTIGEN-ANTIBODY INTERACTION
AFFINITY KINETIC EVALUATION
J. Baniukevič1, J. Kirlytė1, A. Ramanavičius1,
A. Kaušaitė-Minkštinienė1, A. Ramanavičienė1,2
1. VU Nanotechnologijų ir medžiagotyros centras „Nanotechnas“,
Naugarduko g. 24,
LT-03225 Vilnius, Lietuva.
2. Imunotechnologijos sektorius, Valstybinis mokslinių tyrimų institutas
Inovatyvios medicinos centras, Žygimantų 9, LT-01102 Vilnius, Lietuva.
E-mail: [email protected]
Abstract
An immunosensor for the determination of Bovine leukemia virus antigen
(gp51) was developed on the basis of surface plasmon resonance (SPR) analyzer.
During this work the sensor surface coated with gold layer was used for the
immunosensor design. Different conditions of antibodies (anti-gp51) reduction by
2-mercaptoethanol and ditiotreithol solutions were compared and explored. The
highest sensitivity was registered using antibodies reduced with 2-mercaptoethanol.
Through optimization of anti-gp51 immobilization, immunosensor could detect
gp51 antigen in a range from 0.01 to 0.5 mg/mL. The affinity constant was
calculated from the linear variation [1].
The antigen-antibody complex formation efficiency in our system was
achieved 84.4% while Tsai W. et al. [3] registered 90%, respectively. By this way
reduced antibodies‟ fragments were found to be the most suitable for design of SPR
immunosensor for gp51 detection, due to its sufficient antigen binding capacity.
References:
1. Kausaite A, Dijk M, Castrop J, Ramanaviciene A, Baltrus JP, Acaite J, Ramanavicius A
(2007) Biochem. Mol. Biol. Educ. 35: 57-63.
2. Basu I, Ferens WA, Stone DM, Hovde CJ (2003) Infection and Immunity 71: 327-334.
3. Tsai WC, Pai PJR (2009) Microchim Acta 1007.
30
GRAPHITE OXIDATION PRODUCTS: SYNTHESIS AND EXAMINATION
J. Barkauskas, J. Dakševič, I. Šakinytė
Vilnius University, Department of General & Inorganic Chemistry, Naugarduko 24, LT03225, Vilnius, Lithuania
E-mail:[email protected]
Graphite is known as a substance, which is quite resistant to highly oxidizing environments at
room temperatures. Nevertheless, some of the strong oxidizing agents are able to convert
graphite to graphite oxide (GO). This reaction was performed for the first time more than 150
years ago by British chemist B.C. Broodie using a potassium chlorate (KClO3) [1]. Nearly
100 years after Broodie, Hummers and Offeman developed an alternate oxidation method by
reacting graphite with a mixture of potassium permanganate (KMnO4) and concentrated
sulphuric acid (H2SO4) [2]. Though others have developed more or less modified versions [3],
Broodie and Hummers synthesis protocols remain the most popular. In any case, the products
of these reactions show strong variance, depending particularly on the precursor used: the
finer the graphite powder, the higher level of oxidation is achieved [4]. Graphite oxide has
attracted much interest recently as a possible route for the large-scale production and
manipulation of graphene, a material with extraordinary electronic properties. However, the
exact structure of GO still remains elusive despite its various applications. Four main
structural models have been proposed for GO: Hofman‟s model [5], Ruess‟s model [6], Sholtz
and Boehm‟s model [7], and Lerf and Klinowski‟s model [8].
In this research we have synthesized GO using several different synthesis protocols.
Alongside with traditional Broodie and Hummers methods we used a potassium bromate
(KBrO3) in an analogous to Broodie synthesis. Also, we performed the initial stages of preoxidation and pre-exfoliation of graphite precursor having an aim to apply a finer raw
material to the synthesis of GO. For this purpose we used several protocols of pre-oxidation:
with potassium persulfate (K2S2O8) in acid media, potassium hexacianoferrate (K3[Fe(CN)6])
in alkaline media, and hydrogen peroxide (H2O2) in alkaline media. Exfoliated graphite
precursor was synthesized using a thermal treatment of GO at 1000 oC and melting the
mixture of graphite and orthoboric acid.
GO, synthesized using several protocols as well as pre-oxidized and pre-exfoliated graphite
precursors were examined by different methods. Raman spectra were used to evaluate
structural changes in graphene sheets during the stages of GO synthesis. XRD difractometry
was useful to ascertain the lattice parameters of graphite, pre-oxidized and pre-exfoliated
products as well as GO. Potentiometric titration was used to assess amount and position of
functional groups on the surface of GO and pre-oxidized intermediate products. All these data
were useful to construct a general view on the structure of GO, and to make practical
recommendations for the synthesis of GO.
References
1.
2.
3.
4.
5.
6.
7.
8.
B. C. Brodie, Philos. Trans. R. Soc. London, 149 (1859) 249–259.
W.S. Hummers, R.E. Offeman, J. Am. Chem. Soc., 80 (1958) 1339.
S. Chandra, S. Sahu, P. Pramanik, Mat. Sci. Eng. B, 167 (2010) 133–136.
D.R. Dreyer, S. Park, C.W. Bielawski, R.S. Ruoff, Chem. Soc. Rev., 39 (2010) 228–240.
U. Hofmann, A.Frenzel, E. Csalan, Liebigs Ann. Chem., 510 (1934) 1–41.
G. Ruess, Monatsh. Chem., 76 (1947) 381–417.
W. Scholz, H.P. Boehm, Z. Anorg. Allg. Chem., 369 (1969) 327–340.
A. Lerf, H. He, M. Forster, J. Klinowski, J. Phys. Chem. B. 102 (1998) , 4477–4482.
31
SYNTHESIS OF NEW HYDRAZONES POSSESSING CARBAZOLE MOIETY AND
THEIR OPTOELECTRONIC PROPERTIES
Bieliauskas A.,a Martynaitis V.,a Getautis V.,a Jankauskas V.,b Arlauskas K.,b Šačkus A.a
a
Department of Organic Chemistry, Faculty of Chemical Technology, Kaunas
University of Technology, Radvilėnų pl. 19, LT-50524 Kaunas, Lithuania
b
Department of Solid State Electronics, Vilnius University, Saulėtekio 9, LT-10222 Vilnius,
Lithuania
E-mail: [email protected]
Aromatic hydrazones are known as very effective charge transport materials for
optoelectronic and electronic devices. Good enough charge-transporting properties for
technical applications, the simple synthesis and low cost are the advantages of arylaldehyde
hydrazones against other classes of charge transporting materials [1, 2].
The aim of this work is to synthesize acrylaldehydes bearing carbazole moieties and their
hydrazones.
Previously unknown carbazole aldehydes 2 and 5 were prepared upon reacting brominated
carbazoles 1 and 4 with acrolein diacetal under Pd catalysis. In the 1H NMR spectrum of
compound 2 the signal of aldehyde proton was at 9.72 ppm with a coupling constant 3J=7.8
Hz.
Prepared aldehydes 2 and 5 were condensed with N-methyl-N-phenylhydrazine and N,Ndiphenylhydrazine and results in the hydrazones 3a,b and 6a,b as hole transporting materials.
Thermal, optical, electrochemical and photophysical properties of the synthesized derivatives
have been investigated.
References:
1. J. Simokaitiene, A. Danilevicius, S. Grigalevicius, J.V. Grazulevicius, V. Getautis, V. Jankauskas. Synth.
Met., 156 (2006) 926-931.
2. A. Danilevicius, J. Ostrauskaite, J.V. Grazulevicius, V. Gaidelis, V. Jankauskas, Z. Tokarski, N. Jubran, J.
Sidaravicius, S. Grevys, A. Dzena. J. Photochem. Photobiol., A: Chem., 163 (2004) 523-528.
32
SYNTHESIS, ENANTIOMER SEPARATION AND ABSOLUTE CONFIGURATION
OF 9-AZABICYCLO[3.3.1]NONANE DERIVATIVES
V. Bieliūnas, E. Orentas, S. Stončius
Department of Organic Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius,
Lithuania
E-mail: [email protected]
We have demonstrated that chiral cleft molecules based on bicyclo[3.3.1]nonane skeleton
fused with self-complementary hydrogen bonding heteroaromatic moieties form helical
supramolecular structures [1]. En route to novel supramolecular synthons, our attention turned
to the 9-azabicyclo[3.3.1]nonane-2,6-diones 3, which offer a unique advantage to introduce
solubilizing groups into the bicyclic framework at the position not accessible in case of
carbocyclic congeners, i.e. on the apical nitrogen atom. Herein we report on the synthesis,
enantiomer separation and absolute configuration of 9-aza bicyclo[3.3.1]nonane derivatives.
Racemic N-benzyl azadiol 2a was obtained from syn-diepoxide 1 following the reported
procedure [2]. The preliminary results revealed serious difficulties encountered in the
conversion of azadiol 2a to the corresponding diketone 3a. The benzyl protecting group was
therefore replaced with more convenient tert-butyloxycarbonyl group (Boc) to give 2b, which
could be oxidised (RuO2 / NaIO4) to the corresponding racemic diketone 3b.
Attempts to resolve enantiomers of 2a via diastereomeric salts with various enantiomerically
pure acids afforded only partially enriched alcohols (~20% ee). Fractional crystallization of
the diesters 4a-b, obtained from racemic 2a-b and (1S)-(−)-camphanic chloride, afforded
diastereomerically pure compounds. Subsequent hydrolysis of the individual diastereomers
afforded enantiomerically pure diols (−)-, (+)-2a and (−)-, (+)-2b. The absolute configuration
of 3b, both enantiomers of which were obtained by oxidation of the corresponding alcohols,
was determined by using CD spectroscopy.
Acknowledgements: This work was funded by the Research Council of Lithuania (Global
Grant Programme No. VP1-3.1-ŠMM-07-K-01-030).
References
1.
2.
(a) S. Stončius, E. Orentas, E. Butkus, L. Öhrström, O. F. Wendt, K. Wärnmark. J. Am. Chem. Soc., 2006,
128, 8272-8285. (b) S. Stončius, E. Butkus, A. Ţilinskas, K. Larsson, L. Öhrström, U. Berg, K. Wärnmark.
J. Org. Chem, 2004, 69, 5196-5203.
P. Michel, A. Rassat. J. Org. Chem., 2000, 65, 2572-2573.
33
NEW METHOD FOR THE CONSERVATION OF COPPER
E. Borovikovaitė1,2, J. Lukšėnienė2, A. Selskis3, J. Senvaitienė1,2, R. Ramanauskas3, A.
Kareiva1
1
Department of General and Inorganic Chemistry, Faculty of Chemistry, Vilnius
University, Naugarduko 24, LT-03225 Vilnius, Lithuania
2
Pranas Gudynas Centre for Restoration, Lithuanian Art Museum, Rūdninkų 8, LT-01135
Vilnius, Lithuania
3
Center for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9, LT01108 Vilnius, Lithuania
E-mail:[email protected]
The conservation methods for different metals used by conservators and restorators were
developed and verified by centuries. However, a lot of scientific investigations have been
made in order to discover new conservation methods that could be used as alternatives for the
old ones. These investigations are essentially focused on the developing of better quality,
faster, long–term, anticorrosion preservation methods that could be applied in conservation
and restoration of metals [1, 2].
The sol–gel process is an efficient method for producing coatings with different compositions
and having important industrial applications (fibres, aerogels etc.) [3]. In particular, it is
possible to obtain coatings in many compositions on a great variety of substrates. Specifically,
the use of this technique for coating metals was mainly aimed at testing the capability of solgel coatings to improve the oxidation and corrosion resistance of the substrate [4]. Moreover,
the sol–gel method is an environmentally friendly technique of surface protection and had
showed the potential for the replacement of toxic pretreatments and coatings which have
traditionally been used for increasing corrosion resistance of metals [5].
The preparation of methyl – modified coatings by the sol–gel technique to protect the external
surface of copper is discussed. Coatings were obtained by simple sol-gel method.
Tetraethylorthosilicate (TEOS) has been used as a precursor to prepare sol–gel precursors for
the surface treatment of copper. 3% SiO2 sol, trimethylchlorosilane (TMCS) and
hexamethyldisilozane (HMDS) were used for the preparation of methyl–modified silica sols.
Paraloid B 72, Plexisol P 550-40 and polyvinyl butyral (PVB) coatings were also deposited
on the copper substrate for comparison. The coatings were formed on copper plates (1.7 x 5
cm) mechanically cleaned with 1 % sulphuric acid and steel wool (0000#) then washed with
ethanol. Coatings were exposed to artificial ageing in a photochemical reactor.
Measurements were performed before and after the photochemical ageing. The surface
morphology changes of uncoated and coated specimens were investigated by atomic force
microscopy (AFM) and scanning electron microscopy (SEM). The hydrophobicity was
evaluated by contact angle measurements. Photochemical ageing effects were also
characterized by contact angle measurements.
References
1. J. Barrio, J. Chamon, A.I. Pardo, M. Arroyo. J. Solid State Electrochem. 13 (2009) 1767.
2. E. Cano, D.M. Bastidas, V. Argyropoulos, S. Fajardo, A. Siatou, J.M. Bastidas, C. Degrigny. J. Solid
State Electrochem. 14 (2010) 453.
3. J. Zarzycki. J. Sol–Gel Sci. Technol. 8 (1997) 17.
4. M. Guglielmi. J. Sol–Gel Sci. Technol. 8 (1997) 443.
5. W. Boysen, A. Frattini, N. Pellegri,O. de Sanctis. Surf. Coat. Technol. 122 (1999) 14.
34
SYNTHESIS AND PROPERTIES OF POLYMERS POSSESSING 1,3- OR 3,6BIS(DIPHENYLETHENYL)CARBAZOLYL CHROMOPHORES
G. Bubnienė,1 T. Malinauskas,1 M. Daškevičienė, V. Jankauskas,2 V. Getautis 1
1
2
Department of Organic Chemistry, Kaunas University of Technology, Radvilenu pl. 19,
LT-50254 Kaunas, Lithuania
Department of Solid State Electronics, Vilnius University, Sauletekio 9, LT-10222 Vilnius,
Lithuania
E-mail: [email protected]
A great many carbazole containing polymers, oligomers, as well as small molecules, are of
excellent hole transport ability, due to their electrondonating capabilities [1.] Novel carbazole
based derivatives possessing diphenylethenyl fragments have been reported by us recently [2].
Commercial availability and relative cheapness of the starting materials, simple synthetic method,
and number of sites available for easy functionalization, good charge drift mobility and solubility
in common organic solvents makes these precursors attractive building blocks for the
construction of more complex materials for optoelectronic applications. Herein, we present
synthesis and properties of glycidyl-terminated 9H-carbazol-2-ol and its 4,4`-thiobisbenzenethiol
copolymers 1 and 2:
S
N
O
S
S
S
*
n
OH
*
OH
1
2
*
S
O
N
S
*
n
OH
OH
The synthesized polymers were examined by various techniques including gel permeation
chromatography, differential scanning calorimetry, UV and fluorescence spectrometry as well as
xerographic time of flight technique. The ionization potentials of these materials are in the range
of 5.60–5.75 eV as determined by the electron photoemission method. The highest hole mobility,
approaching 10-4 cm2/V s at the 106 V/cm electric field, was observed in the polymer 2 obtained
in the polyaddition reaction of 9-(2,3-epoxypropyl)-2-(2,3-epoxy)-3,6-bis(2,2-diphenylethenyl)karbazole monomer with 4,4`-thiobisbenzenethiol.
References
1. Promarak V., Ichikawa M., Sudyoadsuk T., Saengsuwan S., Jungsuttiwong S., Keawin T. Synth. Met. 157 (2007)
17-22.
2. Bubniene G., Malinauskas T., Daskeviciene M., Jankauskas V., Getautis V., Tetrahedron 66 (2010) 3199-3206.
Acknowledgments
G. Bubnienė acknowledges EU Structural Funds project „„Postdoctoral Fellowship Implementation in Lithuania‟‟ for
funding her postdoctoral fellowship.
35
SYNTHESIS AND REDUCTIVE RING OPENING OF
SPIRO[BENZ[e]INDOLE-2,2’-PIPERIDIN]-6’-ONES
Vida Buinauskaitė,a Sven Mangelinckx,b Norbert De Kimpe,b Algirdas Šačkusa
a
Department of Organic Chemistry, Faculty of Chemical Technology, Kaunas University of
Technology, Radvilėnų pl. 19, LT-50524 Kaunas, Lithuania
b
Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University,
Coupure Links 653, B-9000 Ghent, Belgium
E-mail: vida.buinauskaite@ ktu.lt
Fluorescent compounds are currently useful tools in biological, pharmaceutical and
spectroscopic research. Recently, indole and benz[e]indole derivatives have been reported as
suitable starting compounds for the synthesis of various latent fluorophores [1] and cyanine
dyes [2-3]. Intrigued by these observations and considering the fact that spiro[benz[e]indole2,2‟-piperidin]-6-one derivatives are not previously reported in literature, new derivatives
were synthesized and the ring opening reactions performed.
Me
Me
Me
Me
Me
Base
RI
N
1
Me
Me
N
R
R = Me, Et, Bn
2
O
Me
reductive
ring opening
Me
NH2
Me
I-
N
R
3
N N
H
4
R
O
Scheme 1.
Compounds 4were prepared from commercially available 1,1,2-trimethyl-1H-benzo[e]indole
1 via three step synthesis, previously used for preparation of spiro[indole-2,2‟-piperidin]-6ones [3]: N-alkylation, neutralization of iodide salts 2 and subsequently performed addition of
acryl amide (Scheme 1). The investigation of reduction with several reductive agents (LiAlH4,
AlH2Cl, H2+Pd/C) was carried out.
The structures of products were confirmed by further chemical transformations, NMR, IR and
MS data, elemental and X-ray analysis.
References
1.
2.
3.
4.
G. Clavé, A. Bernardin, M. Massonneau, P.Y. Renard, A. Romieu, Tetrahedron Lett. 47 (2006), 62296233.
L. Strekowskir, C.J. Mason, H. Lee, R. Gupta, J. Sowell, G. Patonay, J. Heterocycl. Chem. 40 (2003),
913-916.
Y-L. Fu, W. Huang, C-L. Li, L-Y. Wang, Y-S. Wei, Y. Huang, X-H. Zhang, Z-Y. Wen, Z-X. Zhang,
Dyes Pigm. 82 (2009) 409-415.
A. Šačkus, J.Degutis, Khim. Geterotsikl. Soedin. 1988 902–904.
36
ACTIVITY OF MARSH ROSEMARY ESSENTIAL OILS AGAINST
MICROMYCETES
R. Butkienė, A. Judţentienė. J. Būdienė, A. Lugauskas
Center for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9, LT01108 Vilnius, Lithuania
E-mail:[email protected]
Many essential oils and/or their components possess antibacterial, antifungal, and
antiviral properties [1], for these reasons volatile oils and plant extracts have a widespread
application in pharmaceutical, food and cosmetics industries.
Aim of the work is to investigate chemical composition of marsh rosemary
(Rhododendron tomentosum H. Harmaja, formerly Ledum palustre L.) essential oils and their
antifungal activity against Penicillium cyclopium Thom and Trichoderma harzianum Rifai.
Plant material was collected near Juodupė (shoots; Rokiškis district) and Šilėnai (shoots;
Vilnius district) villages and in Samanis marsh (shoots and flowers; Utena district) in 2007
The volatile oils were obtained by hydrodistillation (2h) of air-dried material in apparatus
according to European Pharmacopoeia [2]. Oils were analysed using GC/FID and GC/MS;
components were identified according to the computer mass spectra libraries and literature
data [3]. Antifungal screening was conducted using an agar-diffusion method.
Predominant constituents were found to be palustrol (26.9 – 42.8%), ledol (23.1 –
30.8%), myrcene (0.5 – 11.4%) and cyclocolorenones (2.7 – 9.3%) together with identified
furyl compounds and terpenes with menthane carbon skeleton in all samples. Growth of
Trichoderma harzianum was inhibited by all investigated essential oils. The oil richest in
myrcene (8.6%) and limonene (11.0%) totally suppressed development of this fungus after
seven days. A little weaker antifungal activity was observed against Penicillium cyclopium
using shoot (Šilėnai) and flower (Samanis marsh) marsh rosemary oils. These oils influenced
fungus growth only during first three days, while its influence decreased after seven days.
Only two samples of volatile oils containing appreciable amounts of p-cymene (4.4 and 5.0%)
and iso-ascaridol (12.9 and 14.2%) completely suppressed growth of Penicillium cyclopium
Our study has confirmed that Rhododendron tomentosum eessential oils can find
practical application as growth inhibitor of some micromycetes.
References
1.
2.
3.
D. Čvek, K. Markov, J. Frece, T. Landeka Dragičević, M. Majica, F. Delaš, Arh. Hig. Rada Toksikol. 61,
(2010) 191-196.
European Pharmacopoeia, 3rd Edition, pp. 121-122, Directorate for the quality of Medicines of the Council
of Europe (EDQM), Strasbourg, France, 1996.
R. P. Adams, Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry, 4 th
Ed. Allured Publishing Corp., Carol Stream, IL, 2007.
37
SOL-GEL SYNTHESIS AND CHARACTERIZATION OF GADOLINIUM GALLIUM
GARNETS (GGG)
S. Butkutė1, A. Zabiliūtė2, A. Ţukauskas2, G. Tamulaitis2 and A. Kareiva1
1
Department of General and Inorganic Chemistry, Vilnius University,
Naugardukas 24 LT-03225 Vilnius, Lithuania
E-mail: [email protected]
2
Semiconductor Physics Department and Institute of Applied Research, Vilnius University,
Sauletekio 9, LT-10222 Vilnius, Lithuania
Garnets have attracted much attention due to their considerable hardness, high thermal
conductivity and good chemical stability [1]. Moreover, the use of single crystals of garnets
permits to solve a number of important problems of quantum electronics. Gadolinium gallium
garnet (Gd3Ga5O12, GGG) also shows interesting mechanical and optical properties [2].
Numerous investigations are being conducted in the direction of developing technology for
production and study of the properties of single phase garnets. The difficulties related to the
process of growing single phase garnets and machining of them makes necessary the
development of new synthesis methods [3]. The interest manifested in rare earth gallium
garnets was determined by the high tendency toward isomorphic substitutions, which is their
main advantage [4].
Sol–gel method is one of the most important techniques for the synthesis of various
functional materials, because it possesses a number of advantages over conventional
formation techniques, such as homogeneous mixing of the precursors and low processing
temperature [5]. In this study, polycrystalline gadolinium gallium garnet (Gd3Ga5O12, GGG)
powders were synthesized by a sol-gel method from a mixed solution of Ga(NO3)3 and
Gd(NO3)3. The doping effects of different metals (M: Cr, Ce, Fe, Cr/Ce) on the synthesis,
phase purity and physical properties of GGG were also investigated. The starting materials,
such as Cr(NO3)3∙9H2O, (NH4)2Ce(NO3)6, Fe(NO3)3∙9H2O were used in the sol-gel
processing. Tris(hydroxymethyl)aminomethane (C4H11NO3) was used as complexing agent to
certain the homogeneity of the precursor gels. Molar ratio of garnet and metals was GGG:M
0.25, 0.50, 1.0, 3.0, 5.0 and 10.0. The final heat treatment of precursor gels was performed in
air at 1000 oC for 10 h. The phase composition and micro-structure of the garnet powders
were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy
(SEM). The luminescence properties of the end products were also investigated.
References
1.
2.
3.
4.
5.
J. Dong, K.Q. Lu, Phys. Rev. B 43, (1991) 8808.
L. Xianxue, H. Zhang-Gui, L. Jiangtao, Opt. Mater., 29, 7, (2007), 854-857.
O. V. Gorshkova, E. S. Luldn, Glass and Ceramics, 39, (1982), 299-301.
L. Suchow, M. Kokta, Solid State Chem., 5, (1971), 329.
J.C. Boyer, F. Vetrone, J.A. Capobianco, A. Speghini, M. Zambelli, M. Bettinelli, J. Lumin., 106, (2004),
263.
38
INVESTIGATION OF BOROHYDRIDE OXIDATION ON TITANIA
NANOTUBE SUPPORTED Pt-Ni BIMETALLIC NANOPARTICLES
R. Čekavičiūtė1,2, D. Šimkūnaitė1, A. Selskis1, L. Tamašauskaitė-Tamašiūnaitė1
State Research Institute, Center for Physical Sciences and Technology, Savanorių pr.
231, LT-02300 Vilnius, Lithuania
2
Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania
E-mail: [email protected]
1
In the present study we report an improvement of Pt-Ni catalysts by introduction
of a titania nanotubed surface (denoted as TiO2-NTs). The catalysts were prepared
according to the two-step procedure. The first step consists in preparing the TiO2-NTs
electrodes by anodic oxidation of Ti surface in an aqueous sulfuric acid solution
containing some NH4F [1]. The second step is the deposition of electroless nickel
sublayer on the prepared TiO2-NTs followed by its immersion into a platinum-containing
solution. Due to spontaneously occurring partial galvanic displacement of electroless Ni
sublayer with Pt well-adherent platinum-coated nickel (Pt-Ni) films with particle size of a
few hundred nanometers have been fabricated on titania nanotubed electrodes. The
catalysts were characterized using scanning electron microscopy and energy dispersive
X-ray spectroscopy. The electrochemical behavior and electrocatalytic activity of the
catalysts towards borohydride oxidation were measured by means of cyclic voltammetry.
The electroactive area of platinum surface created on fabricated catalysts was determined
from cyclic voltammograms of Pt/TiO2-NTs electrodes recorded in a deaerated 0.5 M
H2SO4 solution at a scan rate of 10 mV s-1.
The electrocatalytic activity values of the fabricated titania nanotube supported
Pt-Ni catalysts under various conditions are compared and discussed on the basis of
electrochemical data. The Pt(Ni)/TiO2-NTs catalysts exhibited a higher electrocatalytic
efficiency as compared to that of the bulk Pt.
The titania nanotube supported Pt-Ni bimetallic nanoparticles catalysts seem to be
a promising anodic material for direct borohydride fuel cells.
Acknowledgement
This research was funded by a grant (No. ATE-03/2010) from the Research Council of
Lithuania.
References
1. T. Tian, X. Xiao, R. Liu, H. She, X. Hu. J. Mater. Sci. 42 (2007) 5539-5543.
39
THE ROLE OF MELATONIN AND CIRCADIAN TIME ON THE MIGRATION OF
LEUKOCYTES INTO PERITONEAL CAVITY UPON IMMUNIZATION
V.Černyšiov1,2, M. Mauricas1, I. Girkontaitė1
State Research Institute Centre for Innovative Medicine, Moletu pl. 29, LT-2021 Vilnius,
Lithuania
2
Vilnius University faculty of Natural Sciences; M. K. Čiurlionio 21/27 LT-03101 Vilnius,
Lithuania
E-mail: [email protected]
1
Melatonin is a hormone mainly produced by the pineal gland [1]. The production of
melatonin by the pineal gland occurs during the night in response to the darkness and is inhibited
by the light. The absence of melatonin synthesis for a long time (pinealectomised animals or
animals kept from the birth under constant light) promotes disorganization of lymphoid organs,
decreased numbers of lymphocytes and defects in lymphocyte activation [2]. It remains unclear
how the number and function of lymphocytes would be affected by a temporary disruption of
circadian clock and decreased synthesis of melatonin. In this study we investigated the influence
of melatonin on the number of cells in the organs of immune system in immunized mice.
Disruption of melatonin synthesis did not influence the amount of cells in thymus, bone marrow,
spleen, lymph nodes and Peyer's patches. However, the amount of peritoneal cells was influenced
by melatonin. The number of peritoneal cells was found to be increased while the melatonin
synthesis was inhibited by disrupted circadian rhythm. Circadian rhythm and melatonin could
influence many functions of organisms including the immune system. The absence of the main
organ of melatonin synthesis (pinealectomysed animals) promotes weight loss in immune organs.
These symptoms could be reversed by melatonin administration. The aim of our study was to
investigate the effect of temporary suppressed melatonin synthesis (caused by disrupted circadian
clock) on the quantity of leucocytes in immunized mice. BALB/c mice were immunized and kept
under (1) normal lighting; (2) constant exposure to the light; (3) exposed to the light and treated
daily with melatonin. The disrupted circadian clock and melatonin synthesis did not influence the
amount of cells in thymus, bone marrow, spleen, lymph nodes and Peyer's patches. However,
mice kept under constant lighting (synthesis of melatonin decreased) had increased number of T
cells and B2 B cells in peritoneal cavity when the immunizations were performed in the evening.
Daily melatonin treatment of mice normalized the cell number. Opposite, when the
immunizations with TD antigen were performed in the morning, a decreased amount of cells in
peritoneum cavity of mice kept at constant lighting as compared with mice at normal lighting was
detected. The number of peritoneal cells in mice kept at normal light/dark conditions depends on
the time of immunization. The amount of those cells was significantly higher when the
immunizations were performed in the morning versus evening. The cell number in peritoneal
cavity of mice kept at constant light conditions was not influenced by the time of immunization.
References:
1. Cardinali, D.P., Vacas, M.I. Cellular and molecular mechanisms controlling melatonin release by mammalian
pineal glands. Cell Mol Neurobiol., 7 (1987) 323-37.
2. Guerrero, J.M., Reiter, R.J. Melatonin-immune system relationships. Curr Top Med Chem., 2 (2002) 167-79.
40
COMBINED REMOVAL OF AZO DYE AND COPPER(II) FROM AQUEOUS
BINARY SOLUTIONS
R. Česūnienė, A. Gefenienė, D. Kaušpėdienė, A. Selskienė
Center for physical sciences and technology, Institute of Chemistry,
A.Goštauto 9, LT-01108 Vilnius, Lithuania
E-mail: [email protected]
Wastewater from textile and dyeing industries contains not only dye materials, but also
other pollutants, such as heavy metals. Uptake of pollutants by adsorbent materials can
involve several mechanisms such as physical-chemical adsorption, ion exchange,
precipitation or complexation [1]. Understanding the interaction mechanism may be very
helpful in improving multi-component adsorption systems [2]. In this work, the effects of
several variables such as azo dye and copper(II) concentration, temperature and pH on the
removal efficiency have been evaluated. Optimization of removal process has been conducted
by batch and column experiments. Activated carbons of basic character were used.
Adsorption of copper(II) and dye on activated carbon was examined from external solutions
of different pH covering the range from pH 3 to pH 6. Activated carbon surface chemistry
influenced the amount of adsorbed copper(II) and dye not only by direct interaction but also
by the modification of external solutions pH [3]. Removal from the solutions with the same
initial pH but with different initial copper(II) concentration leads to different changes in final
pH of the solutions. The mechanism of copper(II) and dye uptake varies at various pH values
since the pH affects the structure of the adsorbent surface and the structure of adsorbate [4].
The results of batch and column adsorption experiments showed higher removal efficiency at
higher pH. For higher pH values the removal efficiency was influenced by the precipitation of
copper(II) hydroxide. The formation of precipitate results in the increased number of
adsorption sites available for azo dye, so that the presence of copper(II) in the mixture
improved azo dye uptake. At lower pH (pH 3), the competition between protons and
copper(II) ions for the same adsorption sites of activated carbon takes place. Nevertheless
even at low pH values the adsorption of dye and copper(II) occurs. It was especially
favourable for the adsorption of dye anions because the surface charge of the adsorbent was
positive. The optimal conditions for the removal of dye and metal ions was found to be at
initial pH 5 and initial copper(II) concentration of 5 10-3 mol/L. When the initial
concentration of copper(II) in the solution was lower than 1 10-3 mol/L, the pH value in
equilibrium solution was high, and the precipitation in the bulk solution prevailed. The
content of the precipitate in the solution decreased with increasing the concentration of
copper(II) ions. The increase of temperature from 18 to 40º C substantially enhanced the
activated carbon adsorptive capacity for azo dye and copper(II) ions. The morphology and
microstructure of carbon samples were observed by scanning electron microscopy before and
after adsorbates uptake. SEM images revealed appearance of crystal structures on the surface
of the adsorbent. The crystal structure of the copper compounds on the surface of activated
carbon was influenced by the initial concentration of copper(II) in the mixture.
References
1.
2.
3.
4.
G. Issabayeva, M. K. Aroua, N. M. Sulaiman, Desalination, 262 (2010) 94-98.
S.-X. Teng, S.-G. Wang, X.-W. Liu, W.-X. Gong, X.-F. Sun, J.-J. Cui, B. Y. Gao, Colloids Surf., A:
Physicochem. Eng. Aspects, 340 (2009) 86-92.
S. Biniak, M. Pakuła, G. S. Szymański, A. Światkowski, Langmuir, 15 (1999) 6117-6122.
K. Pyrzyńska, M. Bystrzejewski, Colloids Surf., A: Physicochem. Eng. Aspects, 362 (2010) 102-109.
41
THIOLIPIDS FOR MODELLING TETHERED BILAYER LIPID MEMBRANES
T. Charkova, O. Eicher-Lorka, A. Matijoška, Z. Kuodis, A. Rutavičius, L. Labanauskas,
G. Urbelis, R. Striela
Institute of Chemistry of Center for Physical Sciences and Technology,
Akademijos 7, LT-08412 Vilnius, Lithuania
E-mail: [email protected]
Membrane related processes have attracted an enormous interest of different scientists.
The construction of an artificial model system, which mimics the natural bilayer lipid
membrane, is an important task. Such a system allows the preparation of ultrathin, highresistance lipid layers on metals or semiconductors and the incorporation of receptor proteins
into these insulating layers in order to design biosensors, bioelectronic or other biomimetic
devices [1-3]. It also opens new paths to investigate membrane-related processes (cell
adhesion, photosynthesis, respiration, drug-protein interactions). One of the most promising
model systems is the tethered bilayer lipid membrane (tBLM) [4,5].
In our ongoing project of developing novel syntheses of different molecular systems
based on tailoring the reactive properties of surfaces we decided to synthesize some new
thiolipids for modelling tBLMs. Initial for this synthesis 1,2-ditetradecylglycerol (7) was
prepared in six steps from optically active D-mannitol 1 with common yield 28%. Then a
spacer group – oligoethyleneglycol (OEG) was attached for further syntheses of disulfide (10)
and thiol (13).
Both thiolipids were used for modelling tBLMs and impedance spectroscopy studies.
It was found that compounds 10 and 13 form stable tBLMs and properties of these systems
are under investigation.
Scheme. The synthesis of thiolipids.
References
1.
2.
3.
4.
5.
D. Chen, J. Li, Surf. Sci. Reports, 61 (2006) 445-463.
J.J. Gooding, F. Mearns, W. Yang, J. Liu, Electroanal., 15 (2003) 81-96.
J.H. Fendler, Chem. Mater., 13 (2001) 3196-3210.
Y.-H.M. Chan, S.G. Boxer, Curr. Opin. Chem. Biol., 11 (2007) 1-7.
W. Knoll, I. Köper, R. Naumann, E.-K. Sinner, Electrochim. Acta, 53 (2008) 6680-6689.
42
SOME PREVENTIVE ANTIOXIDANTS STUDY FOR INK DAMAGED PAPER
1
O. Darčanova1, B. Sivakova2, A. Beganskienė1, A. Kareiva1
Vilnius University, Faculty of Chemistry, Naugarduko 24, LT-03225 Vilnius, Lithuania
2
Martynas Mažvydas National Library of Lithuania Document Conservation Center
Gedimino av. 51, LT-01504 Vilnius, Lithuania
E-mail: [email protected]
The most popular inks, known since Roman times and used till middle of the last
century, are metal-gall inks [1, 2]. These kinds of inks are known to deteriorate paper: it
consist certain transition-metal and his media is acidic. Additionally, these inks contain row
materials, so composition is unstable and volatile. Therefore, stabilization treatment consists
of deacidification and the addition of antioxidants [3]. Deacidification is widely used for
stabilization of all kind of paper documents and books, but antioxidants are still avoided. This
study is for represent the stabilizing potential of this kind of materials.
The separate samples of cotton fiber sheets were treated with various historical writing
inks (iron gall and copper containing) prepared according to old recipes. Dried samples were
immersed into the stabilizing solutions of several antioxidants in 2-propanol. A series of
antioxidants were used such as prophyl gallate, alfa-tocopherole, ethonium,
tetrabutylammonium bromide, phytic acid (also have corrosion inhibitors properties) and
traditional potassium iodide or bromide. The samples were aged in an oven at 105°C for 30
days. The pH measurement, degree of polymerization (DP), some aspects on changing of
sorption properties and IR, absorption spectrum data of non-aged and aged samples will be
presented and discussed.
References
1.
D.L. Thomas, RAMP (Program), Survey on national standards on paper and ink to be used by the
administration for records creation : a RAMP study with guidelines, General Information Programme and
UNISIST, United Nations Educational, Scientific and Cultural Organization, [Paris], 1987.
2. U. Henniges, G. Banik, R. Reibke, A. Potthast, Macromolecular Symposia, 262 (2008) 150-161
3. G. Poggi, R. Giorgi, N. Toccafondi, V. Katzur, P. Baglioni, Langmuir, 26 (2010) 19084-19090.
43
EFFECT OF SURFACE ACTIVE COMPOUNDS ON GELATINIZATION,
GELATION AND GEL PROPERTIES OF STARCHES FROM DIFFERENT
BOTANICAL SOURCES
1
J.Galkin , J.Pivoraite1, A. Galkina1 ,E. Maţoniene1,2, J. Liesiene1
1
Department of organic technology, Kaunas University of Technology, Radvilenu pl. 19, LT50254, Kaunas, Lithuania
2
AB “Amilina”, J.Janonio 12, LT-35101, Panevezys, Lithuania
Starch is a natural material obtained from renewable resources. As for all natural
materials, properties of starch varies much depending on its botanical origin. Starch properties
are strongly influenced by the formation of amylose-lipid complexes, which are present in
case of cereal starches [1].
The main aim of the study was to evaluate the effect of three surface active compounds
(SAC): sodium dodecyl sulfate (SDS), sodium stearate (SST) and sodium oleate (SOL) on
gelatinization, gelation and gel properties of starches from different botanical sources. These
SAC were chosen because of their properties; SDS is well known for a specific complex
formation with proteins and should form amylose- SDS inclusion complex, SST is a salt of
weaker acid and should also form amylose inclusion complex (AIC), while SOL should from
AIC, but in minor amounts, because of one unsaturated bond in hydrophobic part of the
molecule. All additives, SDS, SOL and SST, were added to starch slurry prior analysis at
concentrations of 0.8%, 1.7%, 2.4%, 3.1% based on starch weight. The starch gelation and gel
parameters where analyzed using dynamic mechanical analysis method (DMA), by TA
Instruments AR 2000 rheometer and small amplitude oscillation technique.
SDS additive increased the swelling of wheat and corn starch, but took opposite effect
on potato starch. Gelation and gel properties were affected quite significantly; for wheat
starch more soft gels were produced, for corn starch additive have promoted rigidity of the
gels and increased storage modulus quite significantly, for potato starch additive have
promoted formation of more rigid gels.
SST additive decreased significantly the swelling of wheat starch at concentration of 1.7
% and greater; there was no peak of viscosity (viscosity was close to zero) and as the results,
gels were very soft. Corn starch was affected in similar way; the additive at concentration
greater than 2.4 % restricted swelling and gelatinization, but not completely, gel formation
with 3.1 % of SST was unusual, because during the gelation stage there was huge increase in
all parameters (G‟, G” and delta), but during storage stage the G‟ and G‟‟ went to zero almost.
For other samples of corn starch SST additive decreased the gel rigidity. Potato starch gel was
affected by additive addition in different way; additive promoted rigidity of the gels.
SOL additive decreased the swelling for potato starch in all concentration, but for corn
small concentrations (0.8 % and 1.7 %) promoted swelling; greater concentration decreased
swelling comparing to sample without additive however. SOL additive promoted wheat starch
swelling at all concentrations. Gel properties for wheat and corn starches were affected in a
similar way. Generally, the additive promoted more soft gel formation, potato starch gels
were more rigid with the additive.
All results confirmed a strong influence of minor constituents on the gel formation of
starch. Further investigations should give a tool for the control of starch gelling and gel
properties which are essential in a variety of starch application areas.
References
1. Morphological, thermal and rheological properties of starches from diff erent botanical sources
N. Singh, J. Singh, L. Kaur, N. S. Sodhi, B. S. Gill, Food chemistry 81, 2003.
44
SYNTHESIS AND PHOTOLUMINESCENT PROPERTIES OF RARE EARTH
DOPED Al2O3 FOR SOLAR CELL APPLICATIONS
E. Garskaite1, T. Grande2, M.-A. Einarsrud2, S. Ciorba3, B.S. Richards3,
M. Lindgren4, A .T. J. van Helvoort4 and E. Olsen1
1
Department of Mathematical Sciences and Technology, Norwegian University of Life
Sciences, NO-1432 Aas, Norway
2
Department of Material Sciences and Engineering, Norwegian University of Science and
Technology, NO-7491 Trondheim, Norway
3
School of Engineering and Physical Sciences, James Nasmyth Building, Heriot-Watt
University, EH 14 4AS Edinburgh, United Kingdom
4
Department of Physics, Norwegian University of Science and Technology, NO-7491
Trondheim, Norway
E-mail:[email protected]
Solar cells will play a vital role in providing energy for the future society. Recently,
enhanced efficiency of solar cell devices has been proposed by increased light harvesting
efficiency by non-linear optical processes such as down-conversion and up-conversion of
photons [1-3]. Such photoluminescence processes may modify the spectrum of the available
photons to better fit the band gap of the solar cell device and improve its performance. Al2O3
is used in solar cells as an effective surface passivation layer [4].
In this work rare earth elements are used as phosphors which convert higher energy
photons into lower energy photons (Stokes process) and vice versa (anti-Stokes process). We
will demonstrate this for Al2O3:Eu, Al2O3:Er and Al2O3:Nd,Yb powders and films
synthesized by the sol-gel method. In addition, the photoluminescent properties of the
synthesised materials will be discussed.
References:
1. C. Strümpel et al, Sol. Energ. Mater. Sol. Cells, 91 (2007) 238-249.
2. B.C. Richards Sol. Energ. Mat. Sol. C., 90 (2006) 1189-1207.
3. E. Klampaftis et al, Sol. Energ. Mat. Sol. C., 93 (2009) 1182-1194.
4. J. Schmidt et al, Photovoltaics Int. (2010) 55-57.
45
SYNTHESIS AND ANTILEUKEMIC ACTIVITY OF N- AND OETHOXYCARBONYLMETHYLATED PYRIMIDINONES
V. Gefenas1, D. Bironaitė2
1
Vilnius Pedagogical University, Studentų 39, LT–08106 Vilnius, Lithuania
E-mail: [email protected]
2
State research institute center for innovative medicine, Žygimantų g. 9, LT–0110 Vilnius,
Lithuania
E-mail: [email protected]
Alkylated pyrimidinones and their derivatives have attracted considerable interest due to
their variuos biological activities [1]. Continuing our studies on the alkylation of 2(1H)- and
4(3H)-pyrimidinones [2,3], we report here the synthesis and antileukemic properties of novel
O- and N-ethoxycarbonylmethylated compounds. The interaction of 5-cyano-2-ethylsulfanyl4(3H)-pyrimidinone (1) with ethyl bromoacetate was carried out in the presence of potassium
carbonate in anhydrous acetonitrile medium:
OC2H5
O
O
NC
N
O
NC
OC2H5
Br
NH
SC2H5
N
O
NC
O
2
SC2H5
N
OC2H5
N
O
K2CO3 / CH3CN
SC2H5
N
3
1
NC
O
OC2H5
N
O
4
SC2H5
N
The alkylation products – O-, N(3)- and N(1)-ethoxycarbonylmethylated pyrimidinones
2–4 were easily isolated by fractional crystallization or column chromatography. Structurally
related N(1)-alkylated derivative 6 was prepared by treatment of 5-chloro-2(1H)-pyrimidinone (5)
with ethyl chloro or bromoacetate [2].
OC2H5
X
Cl
NH
O
N
5
O
K2CO3 / CH3CN
(X = Cl, Br)
Cl
OC2H5
N
O
N
O
6
Various concentrations of all tested O- and N-alkylated pyrimidinone derivatives
significantly (40–80 %) caused apoptosis in HL-60, promyelocytic leukemia cells line for
studies of leukemia in vitro. The most effective compounds was N-alkylated derivatives 3
(IC50 = 200 M, 24 h of exposure) and 6 (IC50 = 250 M, 24 h of exposure). The exact
molecular mechanisms of apoptosis induced by these and other tested compounds are under
investigation.
References
1. G. R. Madhavan, R. Chakrabarti, R. K. Vikramadithyan et al., Bioorganic and Medicinal Chemistry, 10
(2002) 2671-2680.
2. V. I. Gefenas, P. I. Vainilavichyus, Khim. Geterotsikl. Soedin., (1984) 1429–1430.
3. V. Gefenas, Ţ. Stankevičiūtė, A. Malinauskas, Khim. Geterotsikl. Soedin., (2009) 1754–1756. [Chem.
Heterocycl. Comp., 45 (2009) 1413–1415].
46
SYNTHESIS AND INVESTIGATION OF POLYURETHANE CAPSULES FROM
POLY(VINYL ALCOHOL) AND ISOPHORONE DIISOCYANATE
I. Gerasimcik, I. Tolkaciova, T. Romaskevic, S. Budriene
Department of Polymer Chemistry, Vilnius University, Naugarduko str. 24, LT-03225 Vilnius,
Lithuania
[email protected]
Microencapsulation provides a simple and cost-effective way to enclose bioactive materials,
such as drugs and cells, within a semi-permeable polymeric membrane for the purpose of
protecting the bioactive materials from unfavorable environment and releasing the enclosed
substances or their products in a controlled fashion [1]. The chemical stability of PVA at
normal temperature along with its excellent physical and mechanical properties have led to its
broadly practical applications. In recent years, much attention has been focused on the
biomedical applications of PVA [2]. Polyurethanes (PU) are one of the most versatile
materials in the world today [3].
However, studies concerning the polyurethane microcapsules are scarce. They concern mostly
the study of the properties of some preparations and very little is known about the influence of
the chemistry of the interfacial process and the structure of the wall of the microcapsules [4].
The current work was aimed at evaluating the encapsulation method of water soluble
materials. Polyurethane (PU) capsules were synthesized from poly(vinyl alcohol) (PVA) and
isophorone diisocyanate (IPDI) by inverse emulsion method.
Aqueous PVA solution was emulsificated in toluene using Span 85 as a surfactant. After that
IPDI was added to reaction mixture. Polyurethane shells of capsules were formed by
polyaddition reaction. The PU capsules were formed by varying reaction conditions: initial
concentration of PVA and surfactant Span 85, molar ratio of PVA and IPDI, reaction time and
volume ratio of water/oil emulsion system.
Increasing concentration of PVA resulted in decreasing yield of shell of microcapsules and
increasing amount of encapsulated material up to 90 %. Yield of shell of microcapsules and
amount of encapsulated material were investigated as a function of concentration of Span 85.
The best results were obtained when 0.58 % of Span 85 was used. Initial molar ratio of PVA
and IPDI was varied from 1:7 to 1:11 and the optimal ratio 1:9 was obtained. Yield of shell of
microcapsules was increased and amount of encapsulated material was decreased when time
of synthesis was prolonged from 2 to 4 h.
The range of PVA-based PU capsules size distribution was 280-600 µm.
The structure of the shell of capsules has been proven by chemical analytical methods and FTIR spectra. It was estimated, that the appearance of characteristic peaks at 1631 cm-1 (amide I,
ν(C-O)), 1566 cm-1 (amide II, δ(N-H, C=N)), 1242 cm-1 (amide III, δ(N-H), ν(C=N))
corresponding to polyurethane were presented. The C-O-C stretching band was observed at
1072 cm-1.
References:
1. S. H. Emami, F. Orang, M. Mahmoudi, M. Rafienia, Polym. Adv. Technol., 19 (2008) 167-170.
2. C. Zhang, X. Yuan, L. Wu, Y. Han, J. Sheng., Eur. Polym. J., 41 (2005) 423-432.
3. T. Romaškevič, S. Budrienė, K. Pielichowski, J. Pielichowski, Chemija, 17 (2006) 74-89.
4. Y. Frère, L. Danicher, P. Gramain., Eur. Polym. J., 23 (1998) 193-199.
47
THE INHIBITION EFFECT OF SODIUM NITRITE AND SILICATE ON STEEL
CORROSION IN CHLORIDE CONTAMINATED ALKALINE SOLUTIONS
O. Girčienė, R. Ramanauskas, L. Gudavičiūtė, A. Martušienė
State scientific research institute Center for Physical Sciences and Technology, Institute
of Chemistry, Goštauto 9, LT-01108, Vilnius 2600, Lithuania
E-mail: [email protected]
The corrosion of steel in concrete is difficult to investigate, mainly because of
experimental problems such as high resistivities, highly porous materials, the cell design
and macro cells. Since the pore solutions in cement and concrete are thought to consist
mainly of aqueous KOH, NaOH and Ca(OH)2, it is possible that the studies of the cyclic
voltammetry of iron in these solutions could be useful as a basis for understanding the
electrochemical corrosion behaviour of steel reinforcement in porous concrete structures
[1, 2].
The effect of chloride ions on the breakdown of passive films formed on carbon
steel in a 0.1 M NaOH solution have been studied and sodium nitrite, sodium silicate and
their synergistic effect on corrosion prevention of carbon steel have been discussed.
The ability of some corrosion inhibitors to protect carbon steel against corrosion
was investigated using the voltammetric and EIS techniques. The surface analysis of
samples was carried out applying XPS. EIS measurements have shown, that prolongation
of steel exposure to solution containing NaNO2 from 0.5 h up to 240 h leads to an
approximately tenfold increase in charge transfer resistance Rt values. After 240 h of
exposure to the solution with the NaNO2+ Na2SiO3 mixture Rt values were about
threefold higher as compared to those obtained in the solution containing only one
inhibitor NaNO2. The XPS data revealed that a 3.5 nm thick passive layer was formed
over 240 hours of carbon steel exposure to the solution with NaNO2. An additional
introduction of Na2SiO3 into the same solution increased the thickness of the oxide layer
by ca. 9-10 nm. In the outer part of the oxide layer Fe was detected in the form of FeO,
while Fe3O4 was the main constituent of the inner part of the oxide layer. When the
duration of steel exposure to the solution with the NaNO2+ Na2SiO3 mixture was
prolonged up to 1 year, the thickness of the passive layer increased markedly and was
>350 nm.
To summarize the results of electrochemical and XPS measurements, the mixture
of NaNO2 + Na2SiO3 inhibitors ensured the most pronounced inhibition of the carbon
steel corrosion in the investigated solution 0.1 M NaOH + 1 M NaCl. The inhibition
efficiency increases due to the synergistic effect of two co-inhibitors.
References
1. L. Freire, X. R. Nóvoa, M. F. Montemor, M. J. Carmezim, Mater. Chem. Phys., 114 (2009) 962-972.
2. M. B. Valcarce, M. Vázquez, Electrochim. Acta, 53 (2008) 5007-5015.
Acknowledgments
This research was supported by the Research Council of Lithuania under Grant Nr. MIP – 77/2010. The
authors thank dr. A. Sudavičius (Institute of Chemistry, Vilnius, Lithuania) for his assistance performing
XPS measurements.
48
GRAPHITE OXIDE AND GRAPHENE COATINGS ON METAL SURFACES
1
E. Graţėnaitė1, J. Senvaitienė1,2, J. Barkauskas1
Vilnius University, Dept. General & Inorganic Chemistry, Naugarduko 24, LT-03225,
Vilnius, Lithuania
2
P. Gudynas Restoration Centre, Rūdninkų 8, LT-01135, Vilnius, Lithuania
E-mail: [email protected]
Free-standing paper-like or foil-like materials as well as coatings are an integral part of our
technological society. Their uses include protective layers, chemical filters, components of
electrical batteries or supercapacitors, adhesive layers, electronic or optoelectronic
components, etc. Inorganic „paper-like‟ materials based on nanoscale components such as
exfoliated vermiculite or mica platelets have been intensively studied [1] and commercialized
as gas-impermeable membranes [2]. Carbon-based flexible graphite foils [3] composed of
stacked platelets of expanded graphite have long been used in packing and gasketing
applications because of their chemical resistivity against most media, superior sealability over
a wide temperature range, and impermeability to fluids and gases.
Graphite oxide (GO) is a layered material consisting of hydrophilic oxygenated graphene
sheets bearing oxygen functional groups on their basal planes and edges. GO can undergo
complete exfoliation in water, yielding colloidal suspensions of almost entirely individual
graphene oxide sheets [4] with a mean lateral dimension of approximately 1 m. From the
information above is obvious that it should be possible to assemble these GO sheets into wellordered macroscopic structures, e.g., membranes or coatings with low permeability and
enhanced anti-corrosive properties.
GO in our study was synthesized using a standard Hummer‟s method [5]. The prepared
product was purified by washing with distilled water through the centrifugation (centrifuge 16P, Sigma GmbH, Germany; 5500 rpm; each run for 20 min) and decantation cycles up to
weak acidic reaction (pH ~ 5). GO aqueous dispersions (GO concentration 1 10–3 g/ml) were
prepared using a sonication equipment (VibraCell VCX-130 ultrasonic processor; Sonics Inc.,
USA). GO coatings on the surface of Al foil were moulded using an evaporation protocol.
Prepared GO coatings of thickness 40 – 400 nm were treated with several different chemical
reagents at different temperatures having aim to convert the GO into graphene flakes.
Permeability and anti-corrosive resistance of GO and graphene coatings were measured using
an automated electronic balance system. The electronic balance (Kern ABJ 120 4 M,
Germany) was connected to a computer via RS232 serial port with a standard Kern software.
The balance measured the change in mass during the reaction between Al foil and 20 %
H2SO4. The break-through curves were used to assess the permeability of GO and graphene
coatings, which can be considered as inversely proportional to anti-corrosive resistance.
References
1. J.J. Kellar, (ed.) Functional Fillers and Nanoscale Minerals: New Markets/ New Horizons. Society for
Mining, Metallurgy and Exploration, Littleton, Colorado, 2006.
2. D.M. Eitzman, R.R. Melkote, E.L. Cussler, AIChE Journal, 42 (1996) 2-9.
3. R.A. Reynolds, R.A.Greinke, Carbon, 39 (2001) 479–481.
4. S. Stankovich, D.A. Dikin, R.D. Piner, K.A. Kohlhaas, A. Kleinhammes, Y. Jia, Y. Wu, S.B.T. Nguyen,
R.S. Ruoff, Carbon, 45 (2007) 1558–1564.
5. W.S. Hummers, R.E. Offeman, J. Am. Chem. Soc., 80 (1958) 1339.
49
CORROSION OF MAGNETRON SPUTTERED NANOCRYSTALLINE
Mg-Cr ALLOYS IN BORATE SOLUTIONS
A. Grigucevičienė, P. Miečinskas, K. Leinartas, P. Kalinauskas, V. Jasulaitienė, R.
Juškėnas, L. Staišiūnas, E. Juzeliūnas
Centre for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9, 01108
Vilnius, Lithuania; E-mail:[email protected]
Magnesium alloys due to their lightweight, stiffness, excellent castability and workability are
valuable materials in numerous technical applications: automotive and aerospace industry,
computers, portable electronic devices, etc. During past decade Mg-based alloys attracted an
increasing interest as biomaterials, which could substitute commonly used stainless steels, Tiand Co-Cr–based alloys [1, 2]. However, application of Mg alloys, especially in traditional
spheres, is highly limited by poor resistance to corrosion, creep and wear. Magnesium is
rather susceptible to galvanic corrosion due to negative value of Mg/Mg2+ standard potential
(-2.37 V). The main reason of poor corrosion resistance is intrinsically low protective
capability of spontaneously formed (hydro)oxide layer. Numerous magnesium protection
methods were suggested [1]; nevertheless, effective and cost competitive means are still in
great demand. Promising protection methods include formation of supersaturated single-phase
and amorphous alloys, surface modification through laser melting, ion implantation, microalloying [1, 3-6].
Nanocrystalline Mg-Cr alloys were formed by DC-magnetron sputtering (UNIVEX 350,
Leybold) in a wide range of concentrations. Composition, structure and grain sizes of the
deposits were studied by SEM microprobe and XRD methods. EIS and DC-voltammetry in
chloride and chloride-free solutions showed that small chromium concentrations (2-8 at. %)
had detrimental effect, while high corrosion resistance was observed when Cr content reached
one third or so. Chromium refinement effect on alloy crystalline structure was determined by
XRD. The mean values of grain sizes were determined as follows: Mg-2Cr – 60.5 nm, Mg8Cr – 44.6 nm, Mg-20Cr – 31.0 nm, Mg-45Cr – 11.0 nm. Mott-Schottky plots showed that
the spontaneous oxide layers were highly doped semiconductors of n-type. Surface
enrichment by chromium during initial stages of corrosion was determined by X-ray
photoelectron spectroscopy method (Escalab MK II, VG Scientific), which promotes
corrosion resistance and provides an opportunity of surface auto-protection (self-healing) in
damaged locations. A conductivity change from n-type to p-type was observed at E = 0.0 V
(Ag/AgCl) in a buffer borate solutions (pH 9.9). The change of conductivity type was
confirmed by photo-electrochemical measurements. The studied alloys show promise for
protection of magnesium, which becomes increasingly important in numerous technical
applications where reduction of weight is of importance.
References
1. J. E. Gray, B. Luan, J. Alloys and Compounds, 336 (2002) 88-113.
2. M. Staiger, A. Pietak, J. Huadmai, G. Dias, Biomaterials, 27 (2006) 1728-1734.
3. C. Blawert, D. Manova, M. Störmer, J.W. Gerlach, W. Dietzel, S. Mändl, Surf. Coat. Technol., 202 (2008)
2236-2240.
4. A. Grigucevičienė, K. Leinartas, R. Juškėnas, E. Juzeliūnas, J. Electroan. Chem., 565 (2004) 203-209.
5. E. Juzeliūnas, A. Grigucevičienė, K. Leinartas, R. Juškėnas, Electrochem. Comm., 6 (2004) 678-682.
6. A. Grigucevičienė, K. Leinartas, R. Juškėnas, E. Juzeliūnas, Mat. Sci. Engin. A, 394 ( 2005) 411-416.
50
PROBING OF NEUROMEDIN B ADSORPTION ON SILVER, GOLD, AND COPPER
ELECTRODES BY SURFACE ENHANCED RAMAN SPECTROSCOPY
I. Ignatjev1, G. Niaura1, E. Proniewicz2, L.M. Proniewicz2
Institute of Chemistry of Center for Physical Sciences and Technology, Goštauto 9, LT01108 Vilnius, Lithuania
2
Regional Laboratory of Physicochemical Analysis and Structural Research, Faculty of
Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
E-mail: [email protected]
1
Interaction of peptides with metal surfaces controls the function of biomolecules in many
important fields including bioelectrochemistry, biocatalysis, construction of biosensors, and
others [1]. To understand and predict such interactions, detailed molecular level information
is required. We have employed surface enhanced Raman spectroscopy (SERS) to probe the
adsorption peculiarities of decapeptide Neuromedin B (NMB) (H-Gly-Asn-Leu-Trp-Ala-ThrGly-His-Phe-Met-NH2) on Ag, Au, and Cu electrode surfaces at controlled potential.
Important task in such studies is reliable assignment of the spectral features [2,3]. Figure 1
compares SERS spectra of NMB adsorbed at Cu electrode surface from solutions prepared
with H2O and D2O solvent. The well-defined band in the vicinity of 1267 cm-1 was visible for
all three studied metals in H2O-based solvent. As one can see this mode disappears in D2O
solution. Thus, SERS solvent isotopic exchange experiments provides possibility to assign the
1267 cm-1 band to Amide-III vibrational mode of adsorbed NMB. Because this mode involves
C N stretching vibration of amide group coupled with NH deformation, it shifts to lower
wavenumbers upon NH/ND exchange at interface. We found potential-dependent shift of
frequency of Amide-III mode for Au, Ag, and Cu electrodes.
Figure 1. SERS spectra of NMB adsorbed on roughened Cu electrode at -0.600 V in solutions prepared with
H2O or D2O solvent. Measurement conditions: 0.1 M Na2SO4 solution containing 0.01 M phosphate buffer
(pH 7.0) and 10-5 M NMB; excitation wavelength, 785 nm; laser power at the sample, 50 mW; integration
time, 300s. Spectra were normalized according to the Phe band near 1003 cm -1.
References
1.
2.
3.
J.J. Gray, Curr. Opin. Struct. Biol., 14 (2004) 110-115.
E. Podstawka, G. Niaura, J. Phys. Chem. B, 113 (2009) 10974-10983.
E. Podstawka, G. Niaura, L.M. Proniewicz, J. Phys. Chem. B, 114 (2010) 1010-1029.
I. Ignatjev acknowledges EU Structural Funds project “Postdoctoral Fellowship Implementation in
Lithuania” for funding his postdoctoral fellowship.
51
SYNTHESIS AND CHARACTERIZATION OF AZOLES WITH PYRROLIDINONE
MOIETY
V. Intaitė1, R. Vaickelionienė1, V. Mickevičius1, G. Mikulskienė2
1
Kaunas University of Technology, Radvilenu pl. 19, 50254, Kaunas, Lithuania,
E-mail: [email protected]
2
Vilnius University Institute of Biochemistry, Mokslininku str.12, 08662, Vilnius, Lithuania,
E-mail: [email protected]
Heterocyclic structures, such as azoles have appeared to be promising because of their
pharmaceutical and agro protective properties [1, 2]. Considering to this some chemical
transformations leading to new five-membered heterocycles – pyrroles, oxadiazoles and
triazoles, containing pyrrolidinone moiety were carried out and structural studies of the
synthesized compounds were performed. The structures of the newly obtained compounds
were proved by 1H and 13C NMR spectral data.
O
N
R
1a-c
O
O
H
N
CS2, KOH
N
R
H
N
NH2
O
2a-c
O
N
O
12a, b
N
13a-c
H3 C
H
N
N
O
O
CH3
H
N
H
N
N
O
NH
a R = H; b R = Cl; c R = Br;
5, 8 R1 = H; 6, 9 R1 = Cl; 7, 10 R1 = OCH3
N
S
CH3CO(CH2)2COCH3, H
+
O
N
N
R
NH
N
S
N
H2N
O
R1
5-7a,
8-10b
O
14b
N
4a-c
O
R
O
O
R
O
H3C
N
N2H4 . H2O
N
CH3
N
R
NH
1) N2H4. H2O;
2) 3N HCl
SO3H
R
N
H
O
R
R
HCl
S K+
3a, c
CH3CO(CH2)2COCH3, H +
CH(OC2H5)3
S
N
N
N
N
H3C
11a-c
S
R1
NH
N
N
S
CH3
The molecular modeling was applied for visualization of the spatial arrangement of molecular
fragments of study compounds to perceive unexpected chemical shifts in NMR spectra. It was
noticed that hydrogen atom of azomethine group in compounds 13a c was observed as four
singlets in 1H NMR spectra and the intensity ratio ones depends on solvent polarity. The
formation of 5-membered heterocycles [3 5] was confirmed by characteristic chemical shifts
of resonances in 13C NMR spectra.
References
A. Husain., M. Ajmal, Acta Pharm., 59 (2009) 223–233.
H. Bektaş, N. Karaali, D. Şahin, A. Demirbaş, Ş. A. Karaoglu, N. Demirbaş, Molecules, 15 (2010) 2427–2438.
M. Dabiri, P. Salehi, M. Baghbanzaden, M. Bahramnejad, Tetrahedron Lett., 47 (2006) 6983–6986.
V. Mickevičius, R. Vaickelionienė, I. Jonuškienė, G. Mikulskienė, K. Kantminienė, Monatsh. Chem., 140
(2009) 1513–1522.
5. K. Anusevičius, V. Mickevičius, G. Mikulskienė, Chemija, 21 (2010) 127–134.
1.
2.
3.
4.
52
DIELECTRIC AND CONDUCTIVE PROPERTIES OF HYDROTALCITE
Maksim Ivanov1, Kristina Klemkaite 2,3, Alexander Khinsky 3, Aivaras Kareiva 2, Juras
Banys1
1
Faculty of Physic, Vilnius University, Sauletekio str. 9 III 817, LT-10222, Vilnius, Lithuania
2
Department of General and Inorganic Chemistry, Vilnius University, Naugarduko str. 24,
LT-03225 Vilnius, Lithuania
3
Amiagus, Savanoriu pr. 290, LT-49473 Kaunas, Lithuania
Hydrotalcite (HT) type materials are made of positively charged two-dimensional sheets
of mixed hydroxides with water and exchangeable charge-compensating anions. The general
formula for the HT materials is [MII1-x MIIIx (OH)2]x+(Am-)x/m∙nH2O, where M are bivalent or
trivalent cations with similar radii, and A is an interlayer anion, usually CO32-. The crystal
structure of hydrotalcite consists of octahedral brucite (Mg(OH)2) like layers. The interlayer
space between each brucite sheets is filled with water and anions that compensate the
positively charged layers. This region is highly disordered and the amount of water is a
function of the temperature, of the water vapour pressure and of the nature of the anions
present [1]. The nature of the layer cations can be changed using a wide range of main group
(e.g., Mg, Al) or transition metal (e.g., V, Cr,
Mn, Fe, Co, Ni) cations [2].
The aim of the present work was to
study classic type hydrotalcite with MII=Mg,
MIII=Al, x=0.25 and Am-=CO32- by means of
dielectric spectroscopy. Dielectric properties
of hydrotalcite dependent heavily on amount
of water, thus two types of samples were
studied – dry samples in vacuum and samples,
which spent 16 hours in distilled water.
It can be clearly seen from figure 1, that
there is quite high conductivity, which can be
a result of water-introduced proton hopping as
Fig. 1: Conductivity frequency dependence
well as water molecule migration. Moreover,
a DC component of conductivity is observed,
which is different from [3].
References:
[1] A.Vaccari, Catal. Today 1998, 41, 53-17.
[2] J. He, M. Wei, B. Li, Y. Kang, D.G. Evans, X. Duan in: D.M.P. Mingos, Stucture and Bonding, SpringerVerlag Berlin Heidelberg 2006, 89-119.
[3] V. Mehrotra, E.P. Giannelis, J. Appl. Phys. 1992, 72, 1039-48.
53
SYNTHESIS OF AMINO SUBSTITUTED 5-NITROSOPYRIMIDINES
V. Jakubkiene V. Linkus, I. Cikotiene
Vilnius University, Naugarduko-24, LT-03225 Vilnius, Lithuania
E-mail: [email protected]
5-Nitrosopyrimidines bearing amino groups in the 4th and 6th position of the pyrimidine
ring possess a large scale of biological activity [1,2]. On the other hand, these compounds
are useful intermediates in the synthesis of fused pyrimidine heterocycles, such a purines,
pteridines, pyrimidobenzodiazepines, etc. [3,4].
Commonly 5-nitrosopyrimidines are prepared by direct nitrosation of the corresponding
pyrimidines with sodium nitrite in aqueous acid solution or with isopentyl nitrite under
neutral conditions [4-6]. Recently it was also reported that some 5-nitrosopyrimidines can
be prepared by intramolecular oxidation-reduction reactions of N-substituted-N-(2,6disubstituted-5-nitro-4-pyrimidinyl)aminoacetic acid methyl esters in basic media [7].
Herein we would like to present our results on the synthesis of several novel 5nitrosopyrimidines 1 by the above mentioned methods.
R3
R3
R4
R2
R1 = H, N
ON
N
N
R1
N
1
R2
, N O ; R2 = CH3, NH
R3 = OH, NHCH3, NH
N
,
R1
N CH2COOC2H5 ;
R ; R4 = H, NO2
We thank Lithuanian Research Council for the financial support (Global Grant No. VP13.1-ŠMM-07-K-01-002).
References
1.
2.
3.
4.
5.
6.
7.
V. Mesguiche, R.J. Parsons, Ch.E. Arris, J. Bentley et al., Bioorg. Med. Chem. Lett., 13 (2003), 217222.
K.L. Sayle, J. Bentley, F.T. Boyle, A.H. Caloert et al., Bioorg. Med. Chem. Lett., 13 (2003), 20793082.
A. Marchal, M. Nogueras, A. Sanchez, J.N. Low et al., Eur. J. Chem., 2010, 3823-3830.
J. Cobo, M. Nogueras, J.N. Low, R. Rodriguez, Tetrahedron Lett., 49 (2008), 7271-7273.
T. Steinlin, A. Vasella, Helv. Chim. Acta, 92 (2009), p. 588-606.
N. Matsumoto, M. Takahashi, Tetrahedron, 58 (2002), 10073-10079.
I. Susvilo, A. Brukstus, S. Tumkevicius, J. Heterocycl. Chem., 43 (2006), 267-276.
54
EXPERIMENTAL AND COMPUTATIONAL STUDY OF REDUCTIVE NHETEROCYCLIZATION OF N-(2-NITROBENZOYL)-1,5-BENZODIAZEPIN-2ONES
R. Jančienė1, A. Vektarienė2, A. Palaima1, D. Podėnienė1
1
VU Institute of Biochemistry, Mokslininku str. 12, LT-08662 Vilnius, Lithuania
E-mail: [email protected]
2
VU Institute of Theoretical Physics and Astronomy, A. Gostauto str. 12, LT-01108 Vilnius,
Lithuania
The transition metal-induced reductive N-heterocyclization has emerged as versatile
strategy for the construction of a variety of heterocyclic compounds [1, 2]. Our aim was
the
synthesis
of
a
new
fused
heterosystem
encompassing
a
quinazolino[1,5]benzodiazepine moiety in its skeleton using mild, simple, economical and
high yielding procedure of reductive N-heterocyclization.
DMAP,
i-Pr2EtN
O2N
O
N
NH
2
R
O
R
+
O
N
O
O
R
R1
H2
2
from 3c
R2
a:
=
=H
b: R1 = H, R2 = CH3
c: R1 = CH3, R2 = H
NO2
N
2
Cl
1
1a-c
R1
O
3a-c
65-80%
from 3a,b
O
O
1c + 3c
N
N
2
R
N
R1
4a,b
65-70%
1-(2-Nitrobenzoyl)-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-ones
3a-c
were
synthesized by treatment of the appropriate 5-acetyl-2,3,4,5-tetrahydro-1H-1,5benzodiazepin-2-ones 1a-c with o-nitrobenzoylchloride. The reduction of the nitro
compound 3a-c to the corresponding amine was conducted under mild conditions (H2/Ni
or 10% Pd/C). This process was nicely accompanied by a simultaneous Nheterocyclization
of
the
resulting
amine
and
gave
5-acetyl-6R2-6,7dihydroquinazolino[3,2-a][1,5]benzodiazepin-13(5H)-ones 4a,b. Unexpected results were
obtained in the case of attempted reduction of nitro compound 3c – the reduction of nitro
group did not occurred. Unchanged compound 3c and its hydrolysis product 1c were
isolated from the reaction mixture. To clarify the reason of such behavior of this 3substituted benzodiazepinone, quantum-chemical reactivity descriptors [3] were
calculated.
References
1.
2.
3.
W. Zhang, J. P. Williams, Y. Lu, T. Nagashima, Q. Chu, Tetrahedron Lett., 48 (2007) 563-565.
M. Akazome, T. Kondo, Y. Watanabe, J. Org. Chem., 58 (1993) 310-312.
M. Karelson, V. S. Lobanov, A. R. Katridzky, Chem. Rev., 96 (1996) 1027-1043.
55
RF Thermal Plasma Synthesis of Core – Shell Alumina Amorphous
Ceramics Nanosized Particles
b
A. Jankeviciutea, I. Mohaib, J. Szépvölgyi and A. Kareivaa
a
Department of General and Inorganic Chemistry, Vilnius University, Naugarduko 24,
LT-03225 Vilnius, Lithuania
b
Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian
Academy of Sciences, P.O. Box 17, Budapest H-1525, Hungary
Plasma, considered as the fourth state of matter, consists of a mixture of electrons, ions and
neutral species; although overall it is electrically neutral. “Hot” or “equilibrium” plasmas can
be characterized by the approximate equality between heavy particle and electron
temperature. Such plasmas are known as thermal plasmas [1]. Plasma technology is an
enabling technology, which integrates processes associated with plasma material interaction
with manufacturing, adds value to conventional materials and makes new types of materials
and material processing techniques possible [2]. Microsized or nanosized, mainly spherical
powders with narrow particle size distribution, can be formed in this way. These powders are
mostly amorphous with small fractions of crystalline material. Thermal plasma treatment
allows the transformation of irregular ceramic particles into spherical ones. Both microsized
and nanosized powders can be produced, depending on the morphology of the starting
powders [3].
The experiment was carried out in apparatus consisted of an RF inductively coupled plasma
torch (TEKNA PL 35) connected to a reactor (3–5 MHz, max 35kW plate power), a cyclone,
a filter unit and a vacuum pump. The plasma torch operated with Ar and He central gases
(15,5 and 7,95 l min-1, respectively) and sheath gases Ar and He (29,5 and 18,55 l min-1,
respectively). The carrier gas was He (5,83 l min-1). The mixture of microsized SiO2,
microsized Al2O3 and KOH were mixed, heated under IR lamp and then fed to the hottest
zone of plasma flame.
The synthesized material was analyzed and be concluded that during RF thermal plasma
characterized. The scanning electron procedure and using simple raw materials,
microscopy (SEM) micrographs have proved nanosized core – shell ceramic particles can
(Fig. 1.) that obtained material consists of be obtained.
spherical nanosized origin. X-ray diffraction
measurements showed that only Al2O3 was
crystalline phase. The results of X-ray
photoelectron spectroscopy (XPS) analysis
allowed us to examine the surface
composition of nanoparticles. The core –
shell structure of material was determined:
crystalline Al2O3 particles were covered with
amorphous K2O – 4.8 SiO2 layer. The results
of thermal gravimetry (TG) proved that
Fig. 1. SEM micrograph of ceramic nanoparticles.
obtained particles are ceramic composites
since there were no significant mass changes
with increasing temperature. Finally, it can
References
1. I. Mohai, J. Szépvölgyi, Chemical Engineering and Processing 44 (2005) 225–229.
2. C.P. Yoganand, V. Selvarajan, V. Cannillo, A. Sola, E. Roumeli, O.M. Goudouri, K.M. Paraskevopoulos,
M. Rouabhia, Ceramics International 36 (2010) 1757–1766.
3. Z. Karoly, J. Szépvölgyi, Z. Farkas, Powder Technology 110 (2000) 169–178.
56
The influence of electrodeposition conditions on structure and optical properties of
ZnO films
V. Jasulaitienė*, R.Kondrotas, R.Juškėnas, A.Selskis
State research institute Centre for Physical Sciences and Technology Institute of
Chemistry, Gostauto g. 9, LT - 01108, Vilnius, Lithuania
email: [email protected]
Zinc oxide (ZnO) is a non-toxic wide band gap (Eg=3.37 eV at room temperature [1])
semiconductor. ZnO attracted much attention due to its versatile application. It is used as
a window layer in solar cells, promising material for UV-light emitting diodes, lasers, if
doped with appropriate metal can act as a transparent conducting oxide [2-3]. In this
work ZnO thin films were potentiostatically electrodeposited on conducting indium-tin
oxide (ITO) coated glass substrate. Electrolyte consisted of 5mM ZnCl2 and 0,1M KCl
acted as supporting electrolyte. Electrodeposition was carried out at different hydrogen
peroxide (H2O2) concentrations and cathodic potencials, meanwhile other experimental
variables were kept at constant: T=75 °C, stirring, deposition time, electrolyte pH. It was
shown that H2O2 concentration has a notable influence on electrodeposited ZnO films
structure and morphology. As H2O2 concentration increases the deposition current
density increases as well which is directly proportional to the growth rate of ZnO films.
Some electrodeposition conditions and properties of the electrodeposited ZnO samples
are summarized in Table 1.
Table 1.
Sample
ZnO-1
ZnO-2
ZnO-5
ZnO-8
ZnO-9
c(H2O2),mM
5
10
5
2,5
5
E, mV
-950
-950
-900
-950
-1000
d, µm
1,3
1,9
0,8
0,9
1,2
v, µm/h
2,6
3,8
1,6
1,8
2,5
Eg, eV
3,44
3,31
3,47
3,54
3,53
SEM analysis revealed that ZnO films were deposited homogenously, compact without
voids at the lowest growth rate. XRD measurements of ZnO films showed hexagonal
wurtzite type crystal structure with preferential crystallite orientation <002> in all
samples. The calculated lattice constants for as-grown ZnO were a=3.2579 Å and
c=5.2218 Å. Values were slightly larger than of bulk ZnO crystal, which is likely due to
incorporation of Cl- during the deposition. Indeed, EDX spectra revealed that ZnO films
contained Cl up to 1,55%. The optical properties also strongly depended on H2O2
concentration. The most transparent films T~70% (λ=500nm) were deposited at the
lowest H2O2 concentration and the calculated band gap from transmission spectra varied
from 3,31 eV to 3,51 eV (see table 1.)
1. D.C. Look, Materials Science and Engineering B 80, (2001) 383–387.
2. . M. Krunks, A. Katerski, T. Dedova, I. Oja Acik, A. Mere, Solar Energy Mater.
Solar Cell, 92 (2008) 1016- 1019.
3. M. Zhang, Z. Zhou, X. Yang, X. Ye, Z. L. Wang, Electrochemical and Solid-State
Letters, 11(9), (2008) D69-D71.
57
EFFECT OF CHEMICAL FACTORS ON THE GROWTH OF BACILLUS CEREUS IN
MODEL FOOD MEDIA
D. Jonkuvienė, J. Šalomskienė
Kaunas University of Technology, Food institue, Taikos pr. 92, LT-51180 Kaunas, Lithuania
Bacillus cereus are widespread soil microorganisms that can easily get into food from the
environment. The growth of bacteria in foods can be inactivated or inhibited by maintaining the
necessary pH and water activity (aw), by the addition of salts or other preservatives, as well as by
freezing of food products.
The aim of the work was to determine the influence of pH, NaCl, and aw on the growth of
mesophilic and psychrotrophic B. cereus in model food media after 48 h and 160 h incubation at
25 °C and 3±2 °C, respectively.
Methods.
14 strains of B. cereus isolated from food products (confirmed as B. cereus on the chromogenic
BACARA medium) were used for investigation. These strains were assigned to mesophiles or
psychrotrophes according to their growth at 3±2 oC and 42 oC using plate count method. Effect of
chemical factors on B. cereus were determined in model food media: mashed potatoes, cooked
rice, meat broth, cooked minced fish and sweetened condensed milk, contaminated by B. cereus
appr. to 105 – 106 cfu/g. Chemical and physical characteristics - moisture content, total fat and
protein content, aw and pH – of studied food media models were determined. The dependence of
B. cereus growth from pH and NaCl was investigated at pH values 4.0, 5.5, 7.0, 9.0 and NaCl
concentrations of 1 %, 7 %, and 8 %.
Results.
The influence of pH and NaCl on the growth of 7 mesophilic and 7 psychrotrophic strains of B.
cereus was determined. NaCl concentrations of 7 % and 8 % and pH 5.5 and 4.0 inhibited the
growth of psychrotrophic B. cereus at 25 ° C with the exception of cooked rice (its pH 5.5 did not
inhibit B. cereus growth). Mesophilic B. cereus were more sensitive to the impact of the factors
examined: after 48 h incubation at 25 °C the culture growth was inhibited at pH 4.0 of the
medium in all investigated model food media, while it was inhibited at pH 9.0 only in meat broth.
Examination of various factors on the growth of mesophilic and psychrotrophic B. cereus at the
refrigeration conditions showed that the mesophilic B. cereus remained viable in model food
media, although the number of colony forming units decreased. All psychrotrophic B. cereus
could growth at 3±2 °C when NaCl concentration was 0 % and 1 % in the mashed potatoes and
meat broth. Two psychrotrophic cultures could growth in mashed potatoes, meat broth, cooked
rice and cooked minced fish at the pH 9.0. The calculation of the growth parameters of B. cereus
cultures (the average rate of bacteria proliferation and generation time) in model food media, in
case when the investigated factors did not inhibit the growth of these bacteria, showed that the
average rate of cell proliferation was significantly lower and the generation time was longer than
in control medium (brain heart infusion).
Conclusions.
The growth inhibition or complete inactivation of Bacillus cereus in model food media was in
dependency from the duration and temperature of food storage, concentration of NaCl, pH and aw
values and strain of B. cereus.
The investigated factors that had a strong bacteriostatic effect on the viability of B. cereus at 25
°C in the model food media had a less bacteriostatic effect at 3±2 oC.
The internal factors of model food media – aw, pH, NaCl, product composition - delayed the
growth of B. cereus but it was not inhibited under optimal parameters of the food medium.
58
ELECTROCHEMISTRY OF HYDROGEN: H+2 ION AS MAIN INTERMEDIATE IN
REVERSIBLE HYDROGEN EVOLUTION AND OXIDATION REACTIONS
J. Juodkazytėa, B. Šebekaa, S. Juodkazisb, K. Juodkazisa
a
Center for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9,
LT-01108, Vilnius
E-mail: [email protected]
b
Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne
University of Technology, Hawthorn, VIC, 3122, Australia
The mechanism of reversible hydrogen evolution and oxidation reactions (HER and
HOR) is revisited based on detailed thermodynamic analysis and survey of recent literature
data. An assumption about the participation of adsorbed hydrogen atoms as intermediates in
these processes, which was made about half a century ago and cannot account for a number of
recent experimental observations, is critically analyzed. We propose that adsorbed molecular
ion ( H +2 )ad acts as intermediate in HER and HOR as described by the following sequence of
reactions:
H3 O+ + e
( H+2 )ad + OH
(1)
( H+2 )ad + e
OH + H3O+
2H3O+ + 2e
Overall reaction:
H2
2H2O
H2 + 2H2O.
(2)
(3)
HER
New insights into the surface electrochemical processes taking place on Pt electrode at E
ERHE (RHE - reference hydrogen electrode) as well as electrocatalysis of HER at E < ERHE,
i.e. under overvoltage conditions, are obtained. The presented concept explains quantitatively
the HER and HOR phenomena observed experimentally (Fig. 1).
-100
H3O red,
-2
ic / A cm
i0
+
+
H2 ads
+
H2 red
-50
+
H3O ads
+
H3O des
50
H2 ox
+
H2 ox,
+
H3O ads
100
i0
0.4
0.2
HOR
ia / A cm
-2
0
0.0
-0.2
E / V (RHE)
Fig. 1. Calculated overall CVs and partial processes of HER and HOR on Pt electrode within E range from 0.4 V
to –0.05 V. The filled profile shows the digitized experimental voltammogram from ref. 1.
References
1. G. Jerkiewicz, G.Vatankhan, J. Lessard, M. P. Soriaga, Y.-S. Park, , Electrochim. Acta 49 (2004) 1451-1459.
59
THE EFFECT OF ANILINE MONOMER COMPOUNDS STRUCTURE ON
POLYMER FORMATION AND REDOX PROPERTIES
I. Jureviciute*, A. Selskis, A. Malinauskas,
Center of Physical Science and Technology, Institute of Chemistry, A. Gostauto 9, LT-01108
Vilnius, Lithuania
E-mail:[email protected]
One of the possible applications of polymer modified electrodes is electrochemical
analysis. Many authors use polymer modified electrodes for quantitative determination of
various compounds: ascorbic acid [1-4], dopamine [3-4], uric acid [3-5] ethanol [6], H2O2 [7],
etc. Most important features for use of polymer modified electrodes as (bio)sensors are: the
stability of working electrode and high sensitivity. Variation of structure of monomer gives
the possibility to vary the structure and thickness of the polymer layer formed thus changing
electrochemical properties of the film.
The aim of this work was to form polymer modified electrodes using different aniline
derivatives and to analyse the structure and redox properties of the formed films.
The comparison of the results obtained during electro-deposition of polymer films on Pt
electrode from acid solutions, containing aniline (ANI), N-methylanililne (NMA), N,Ndimethylaniline (DMA), N,N-diethylaniline (DEA) and o-toluidine (OT) is presented.
The results show, that the thickness of electroactive layer, calculated from CV curves
obtained on polymer modified electrodes in background solutions depend on the number,
position and length of the side chain in aniline monomer. There is a possibility to enlarge the
thickness of the active polymer layer by adding surface active materials into the deposition
solution. The effect of modified electrode polymer material on the strength of the
electrochemical signal of oxidation of ascorbic acid is also described in this work.
References
1.
2.
3.
4.
5.
6.
7.
P. J. O‟Connell, C. Gormally, M. Pravda, G.G. Guilbault, Analytica Chimica Acta 431 (2001) 239–247.
I. G. Casella and M. R. Guascito, Electroanalysis 9 (18) (1997) 1381-1386.
R. Zang, G.-Di Jin, D. Chen, X.-Y. HuIn, Sensors and actuators B 138(1) (2009) 174-181
A. A. Ensafi, M. Taei, T. Khayamian, A. Arabzadeh, Sensors and Actuators B: 147 (2010) 213-221.
F. Sekli-Belaidi, P. Temple-Boyer, P. Gros, J. Electroanal.Chem.647 (2010), 159-168.
A. P.Periasamy, Y. Umasankar, S.-M. Chen. Talanta, 83 (2011) 930-936.
T. Endo, Y. Yanagida, T. Hatsuzawa Measurement, 41(9) (2008) 1045-1053.
60
CHANGES OF CD8+CD44h LYMPHOCYTES DURING GROWTH OF SL2 TUMORS
IN DBA/2 MICE
J.Juršėnaitė1, D. Characiejus1,2
State Research Institute Centre for Innovative Medicine, Moletu pl. 29, LT-2021 Vilnius,
Lithuania
2
Faculty of Medicine, Vilnius University, M. K. Čiurlionio 21, LT-03101 Vilnius, Lithuania
E-mail:[email protected]
1
Numerous studies have demonstrated that the immune system, especially T-cellmediated cytotoxic responses, plays a significant role in the control of tumour development
and progression (1). CD8+ T lymphocytes are principally known for their role in cytotoxic
killing of virus-infected and tumour cells (2). CD44 is a marker of a family of 85–200kDa
transmembrane glycoproteins that are widely expressed in a variety of cell types. Effectors
and memory cells express high levels of CD44 antigen. CD44h is recognized as a marker of
memory phenotype and also as an activation marker of naïve T lymphocytes. CD44+ T
lymphocytes may also be involved in tumour growth (3). The aim of the study was to evaluate
the role of CD8+CD44h lymphocytes during growth of SL2 tumours in DBA/2 mice.. Two
SL2 tumours were implanted by subcutaneous injection of 107 tumour cells in the same
DBA/2 mouse with the interval of 2 days. We evaluated the numbers of CD8+CD44h cells in
peripheral blood of DBA/2 mice by flow cytometry and compared with the numbers of these
cells in control mice. We also investigated the influence of CD8+CD44h cells on the growth of
SL2 tumours. The results of our study show, that percentages of CD8+CD44h cells in the
CD8+ subset were significantly increased in peripheral blood of DBA/2 mice compared with
control mice (59.33% ± 20.54% versus. 20.97% ± 5.14%, p = 0.0093). Time-course
experiments also showed that the percentage of CD8+CD44h cells in the CD8+ subset in the
peripheral blood increases during tumour growth (17.72% ± 5.14% on day 0, 12.13% ± 5.27%
on day 5 and 27.65% ± 6.97% on day 9; the difference between day 0 and day 9 is statistically
significant, (p=0.013). However, no correlation was found between changes in CD8+CD44h
cells and the weight or the volume of SL2 tumours. Thus, despite cell-mediated immunity is
generated during growth of SL2 tumours in DBA/2 mice, it does not exert a critical role in
progression of SL2 tumours.
References:
1 Swann JB, Smyth MJ. Immune surveillance of tumors. J Clin Invest., 117(5) (2007) 1137–46.
2. Tsukishiro T, Donnenberg AD, Whiteside TL. Rapid turnover of the CD8(+)CD28(-) T-cell subset of effector
cells in the circulation of patients with head and neck cancer. Cancer Immunol Immunother. 52(10) (2003 Oct)
599-607.
3. Dobrzanski Mark J, Reome Joyce B, and Dutton Richard W. Type 1 and Type 2 CD8 + effector T cell
subpopulations promote long-term Tumor Immunity and Protection to Progressively Growing Tumor.
J.Immunol. 164 (2000) 916-925.
61
ELECTROCHEMICAL DEPOSITION OF ZnSe COATINGS AND THEIR
CHARACTERISATION BY STRUCTURAL AND PHOTOELECTROCHEMICAL
METHODS
R. Juškėnasa, V. Pakštasa, A. Selskisa, V. Karpavičienėa, D. Aviţinisb
a
Center for Physical Sciences and Technology, Institute of Chemistry, A Goštauto 9, LT01108 Vilnius, Lithuania
E-mail:[email protected]
b
Vilnius University, Faculty of Chemistry, Naugarduko 24, LT-03225 Vilnius, Lithuania
ZnSe is an n-type semiconductor with wide band gap (2.7 eV) and has a wide range of
technological applications. The electrodeposition of ZnSe has been widely investigated during
past 30 years. The most promising appliance of the electrodeposited ZnSe could be
fabrication of the Cu2ZnSnSe4 (CZTSe) absorber layer in thin film solar cells. When
electrochemically manufacturing the CZTSe zinc, Cu-Zn or Cu-Zn-Sn layer is
electrodeposited. However, it is known that Zn or its alloy electrodeposited from non-cyanide
solution always contains Zn/Zn(OH). [1, 2]. To overcome this shortcoming Zn could be
electrodeposited as ZnSe.
Studies of electrochemical deposition of ZnSe coatings were carried out in water solution
containing 0.2 mol l-1 of ZnSO4 and 0.002 mol l-1 of H2SeO3 with pH 2 [3]. The deposition
was carried out onto Cu substrate at the solution temperature of 20
2 C. The
electrodeposited ZnSe was characterized by XRD (D8 Advance, Bruker AXS), SEM and
EDX (EVO-50 EP, Carl Zeiss) and a photoelectrochemical response was measured in a homemade cell in 0.2 mol l-1 aqueous solution of K2SO4.
Cyclic voltammograms measured in a potential range from 0.0 to 1.0 V against Ag/AgCl
reference electrode revealed 3 cathodic and 2 anodic maximums. XRD studies evidenced that
the most negative cathodic maximum indicated formation of nanostructured ZnSe while
coatings deposited at the most positive cathodic maximum presented orthorhombic Cu2Sex
and, possibly, an amorphous Se. SEM secondary electrons images showed that ZnSe coatings
were solid, without cracks though presented granular formations of various sizes at the
surface of coatings. The XRD studies of deposits obtained by the cycling in potential range
between 0.62 V (third cathodic maximum) and 0.30 V (second anodic maximum) disclosed
the presence of second ZnSe phase with a hexagonal close packed crystal structure along with
a cubic one. The electrodeposited ZnSe coatings showed a rather strong photoelectrochemical
response yielding photopotential of +0.0365 V when illuminated with a light of wavelength
455 nm. This result evidenced the formation of p-type semiconductor with a band gap of ~ 2.7
eV.
The annealing of ZnSe coatings on the copper substrate at the temperature of 300 C in Ar
atmosphere for 3 h led to the formation of the cubic ZnSe and Cu2Sex that was proved by
XRD.
References
1.
2.
3.
T. Vagramyan, J.S.L. Leach, J.R. Moon, Electrochim. Acta, 24 (1979) 231–236.
R. Juškėnas, V. Karpavičienė, V. Pakštas, A. Selskis, V. Kapočius, J. Electroanal.Chem., 602 (2007) 237–
244.
R. Kowalik, P. Ţabinski, K. Fitzner, Electrochim.Acta, 53 (2008) 6184-6190.
62
SERS STUDY OF THE INTERACTION OF PERCHLORATE ANION WITH
POSITIVE CHARGE BEARING MERCAPTOHEXYLPYRIDINIUM MONOLAYER
ON GOLD ELECTRODE
I. Kairytė, Z. Kuodis, A. Matijoška, O. Eicher-Lorka, G. Niaura
Institute of Chemistry of Center for Physical Sciences and Technology, Goštauto 9, LT-01108
Vilnius, Lithuania
E-mail:[email protected]
Self-assembled monolayers (SAMs) bearing charged functional groups provide possibility to
built layered structures at interface in controllable manner and detect ionic species in solution
at low concentrations [1]. In order to construct functional charged structures with predictable
properties, molecular level understanding of ionic interactions at interface is required. Being
surface and molecular specific and highly sensitive, surface enhanced Raman spectroscopy
(SERS) is able to provide such information [2,3]. We have constructed positively charged
SAM by adsorption of N-(6-mercapto)hexylpyridinium (MHP) on gold surface from
acetonitrile solution and probed the interaction of ClO4- ion with pyridinium group in aqueous
solution by SERS technique. Formation of ion pairs at interface is evident from the
appearance of intense symmetric stretching vibration of anion near 933 cm-1 in the SERS
spectrum. We found that frequency of this band depends on the adsorption time of anion from
diluted solution (Fig. 1). This indicates that solvation shell of the anion is more perturbed at
the initial adsorption stage.
Figure 1. Dependence of the frequency of the symmetric stretching vibration of ClO4- ion on the
adsorption time at the MHP monolayer on gold electrode from aqueous 10-6 M NaClO4 solution. SERS
spectra were recorded with 785 nm excitation wavelength and 30 mW laser power at the sample.
Moving spectroelectrochemical cell is employed.
References
1.
2.
3.
A. Ulman, Chem. Rev., 96 (1996) 1533-1554.
M.A. Bryant, J.E. Pemberton, J. Am. Chem. Soc., 113 (1991) 3629-3637.
I. Razmute-Razmė, Z. Kuodis, O. Eicher-Lorka, G. Niaura, Phys. Chem. Chem. Phys., 12 (2010) 45644568.
63
HIGH SENSITIVE ANALYSIS METHOD FOR THE DETERMINATION OF
ALPRAZOLAM, MIDAZOLAM AND THEIR α-HYDROXY METABOLITES IN
BLOOD, USING GAS CHROMATOGRAPHY-NEGATIVE-ION CHEMICAL
IONIZATION MASS SPECTROMETRY (GC/NICI-MS)
Nerijus Karlonas a, b, Almira Ramanavičienė a, Arūnas Ramanavičius c
a
Department of Analytical and Environmental Chemistry, VU, Naugarduko 24, LT-03225
Vilnius, Lithuania; E-mail: [email protected]
b
State forensic medicine service under the Ministry of Justice of the Republic of Lithuania,
Didlaukio 86E, LT-08303 Vilnius, Lithuania
c
Department of Physical Chemistry, VU, Naugarduko 24, LT-03225 Vilnius, Lithuania
The gas chromatography-negative-ion chemical ionization mass spectrometry
(GC/NICI-MS) is the fastest method for the simultaneous identification and quantitation of
various alprazolam (AL), midazolam (MI) and their α-hydroxy metabolites (α-AL and α-MI).
Hypnotic agents are widely used in daily clinical practice due to their multiple
pharmacological actions, and also the large-scale of toxicological application for multiple
analyte determination based on fast GC/NICI-MS methodology [1-4]. Sensitive and specific
NICI-MS detection combined with various characteristic GC parameters resulted in sharp and
symmetric peaks shape of the target analytes in chromatographic separation of 4.9 min, while
still maintaining sufficient resolution.
Initially, chromatographic conditions like injector, interface, initial and final column
temperature, as well as column temperature rate and carrier gas flow rate were optimized.
Different derivatization reagents were tested and it was found that AL, MI and their αhydroxy metabolites were most efficiently derivatized by N-methyl-N-(tertbutyldimethylsilyl)- trifluoroacetamide (MTBSTFA) for the derivatization of the free
hydroxyl groups. The derivatization conditions, reaction temperature and time were also
optimized.
The recovery efficiency of each analyte in blood samples was investigated by liquidliquid extraction (LLE) in the wide pH range of 1.5-13.0. The results showed that better
quantitative recovery was achieved under alkaline conditions (pH> 8), if compared with
acidic (pH< 6) or neutral (pH= 7) conditions, respectively. In particular, the quantitative
recovery of analyte determined by GC/NICI-MS method was best at pH range of 9.0-10.0.
For the compounds determined by GC/MS method, the recoveries were consistent with pH
9.5 and were higher.
The limit of detection and limit of quantification of all analytes tested were calculated
to range between 1.4-2.6 ng/ml and 4.2-7.9 ng/ml, respectively. During the 10 ng/ml200 ng/ml detection region of analyte in blood, coefficients of linearity (R2) varied from 0.981
(α-MI), 0.988 (α-AL), 0.992 (AL) to 0.993 (MI). The average RSD (%) of 12 replicates and 7
concentration points for each analyte in the linearity range were 1.47% (MI), 1.49% (AL),
1.60% (α-MI) and 1.72% (α-AL), respectively.
The extraction efficiency and high recovery percentages show the applicability of the
extraction system in spite of a low volume of organic LLE solvent (n-butyl acetate), low
organic/aqueous phase ratio (3:3) and rapid LLE mixing procedure (5 min). Recoveries
established at the four concentrations (20 ng/ml, 50 ng/ml, 70 ng/ml, 100 ng/ml) ranged from
89.2 % to 104.2 % for blood samples.
References
1. D.Coassolo, C. Aubert, P. Coassolo, J. Cano, J. Chromatogr., 487 (1989) 295-311.
2. H. Gjerde, E. Dahlin, A. S. Christophersen, J. Pharm. Biomed. Anal., 10 (1992) 317-322.
3. P. Frank, J. Jung, T. Kraemer, H. Maurer, Ther. Drug Monit., 27 (2005) 334-344.
4. T. Gunnar, K. Ariniemi, P. Lillsunde, J. Chromatogr., B, 818 (2005) 175-189.
64
SYNTHESIS AND OPTICAL PROPERTIES OF CaLu2Al4SiO12 DOPED BY Ce3+
A. Katelnikovasa,b, A. Kareivab, and T. Jüstela
Department of Chemical Engineering, Münster University of Applied Sciences,
Stegerwaldstr. 39, D-48565 Steinfurt, Germany
b
Department of General and Inorganic Chemistry, Vilnius University, Naugarduko 24, LT03225 Vilnius, Lithuania
E-mail: [email protected], [email protected]
a
A range of Ce3+ doped CaLu2Al4SiO12 samples was synthesized by a sol-gel method
employing ethylene glycol as a chelating agent. Obtained samples were characterized by
powder X-ray diffraction (XRD) and photoluminescence (PL) techniques.
The XRD measurements showed that the garnet phase was nicely formed if powders were
annealed at 1500 °C (see fig. 1) for several hours under CO atmosphere. A further increase of
the annealing temperature (> 1500 °C) resulted in molten samples, which indicates that the
melting point of the target materials are above 1500 °C.
Photoluminescence measurements revealed that the spectral position of Ce3+ emission band is
rather sensitive to the Ce3+ concentration. It turned out that the emission band maximum
clearly shifts to the red spectral range upon increasing the Ce3+ concentration. This can be
explained by re-absorption of emitted photons by the activator. Samples possessed strong
absorption in the blue spectral region and high transmittance at longer wavelengths (see fig.
2). They are thus very attractive for application in phosphor converted LEDs.
Fig 1. XRD pattern of CaLu2Al4SiO12:0.5%Ce3+
sintered at 1500 °C.
Fig 2. Emission, excitation and reflection spectra
of CaLu2Al4SiO12:0.5%Ce3+ sintered at 1500 °C.
The emission maximum of the phosphor samples is centred at around 525 nm and slightly
shifted towards the blue spectral range relative to the widely applied Lu3Al5O12:Ce
(LuAG:Ce), which emission band peaks at 540 nm.
Optical properties of all phosphor powders were studied as a function of temperature and Ce3+
concentration on the dodecahedral lattice site. Furthermore, quantum efficiencies (QE),
luminous efficacies (LE), and CIE 1931 colour points were also calculated and will be
discussed in view of the application as colour converter.
65
ANION EXCHANGE RESIN BEHAVIOR IN REMOVAL OF DYE FROM AQUEOUS
SOLUTIONS
D. Kaušpėdienė, E. Kazlauskienė, A. Selskienė, A. Gefenienė, R. Butkienė
Institute of Chemistry of Center for Physical Sciences and Technology,
A.Goštauto 9, 01108 Vilnius, Lithuania
E-mail: dana@ktl. mii.lt
The removal of dyes (chromium complex - Lanasyn Navy M-DNL and copper
complex - C.I. Acid Blue 249) from aqueous one-component solutions and from their
equimolar mixture by sorption in the Purolite A 847 weak base anion exchange resin-packed
columns was investigated. The comparison of FTIR spectra of unloaded and dye-loaded anion
exchanger established the miscellaneous interactions between the dye and anion exchanger. In
the FTIR spectrum of the dye-loaded anion exchanger the shift of the peaks from 2710 cm-1
and 1479 cm-1 (related to the –NH stretching vibrations and C-N groups vibration,
representing the functional group of anion exchanger –NH+(CH3)2) and the rise of vibration at
1031cm-1, related to the functional groups of dye –SO3-, were recorded. That could be due to
new bonds formed between the anion of the dye (R‟(SO3)44-) and the functional groups of
anion exchanger (-NH+(CH3)2) in the OH- form. The physical sorption and - dispersion
forces can also result from the aromatic nature of the anion exchanger and chromium/copper
complex dye. The aromatic rings (divinylbenzene) and the -C=O groups in Purolite A 847 and
the –SO3H, -N N- groups, the aromatic rings in the chromium/copper complex dye structure
can participate in covalent, coulombic, hydrogen or weak van der Waals forces interaction [13].
The breakthrough curves (the ratio of the effluent concentration to the influent
concentration c/c0 as a function of time t for the given bed height) illustrating the column
operation were obtained from experimental data. The anion exchanger performance
parameters such as the breakthrough capacity of the column and the mass transfer coefficient
depended on the content of the sulpho groups in the chemical structure of dye molecule and
were lower for dye with the four-sulpho groups (C.I. Acid Blue 249) than they for dye with
the two-sulphonate groups (Lanasyn Navy M-DNL). Whereas the mass transfer in the dye
mixture was significantly hindered by the possible competition effect of the uniform charge to
the positive electric charge of amine functional groups of anion exchanger.
Several theoretical models were applied to the experimental data obtained from
dynamic studies performed on fixed bed columns to predict the breakthrough curves and to
determine the column kinetic parameters such the effective kinetic coefficients of the mass
transfer, the breakthrough time or the breakthrough point and the sorption capacity of the
column. The simulation of the whole breakthrough curve was effective with the BohartAdams (APE<14.7%) and with the Juang models (APE<5.2%). From practical point of view,
the simulation of the whole breakthrough curve is not necessary, when the industrial water is
recycled. A linear relationship between ln(c/c0) and time at a given bed height and flow rate
was obtained in the initial region of effluent concentration (c 0.5 c0), suggesting that this
segment of the breakthrough curve fits the Wolborska model, allowing the kinetic mass
transfer in the fixed bed to be estimated.
References
1.
2.
3.
V. Dulman, C. Simion, A. Bârsãnescu, I. Bunia, V. Neagu, J. Appl. Polym. Sci., 113 (2009) 615-627.
N. Sakkayawong, P. Thiravetyan, W. Nakbanpote, J. Colloid Interface Sci., 286 (2005) 36-42.
K. H. Chu, J. Hazard. Mater., 177 (2010) 1006-1012.
66
METAGENOMIC DNA AS THE OBJECT FOR THE NEW BIO-CATALYSTS
DISCOVERY
Ieva Kazlauskaitė, Jurga Aleksejūnaitė, Rimantas Šiekštelė, Inga Matijošytė*
1
Vilnius university Institute of Biotechnology, Sector of Applied Biocatalysts,
V.A. Graičiūno str. 8-255, LT-02241, Vilnius, Lithuania,
*E-mail:[email protected]
Any object that exists at the expense of catalytic activity- from viruses to humans, can
become a source of new bio-catalysts used in the processes of organic chemistry. The choice of
bio-catalyst rather depends on its functional characteristic than from the source of its origin.
Numerous methods for the new bio-catalysts reception eventually converge to a way for
determination of the appropriate DNA fragment. We are looking for the genes codding for
enzymes with enhanced activity for esterification, transesterification, oxidation and hydrolysis
reactions. The search take place not only in the DNA library of specific microorganisms and
fungi, but also in the DNA of metagenomic origin. The DNA library is prepared on the basis of
the modified BAC type vector capable accept high molecular weight (hmw) DNA molecules (50100kb long) and in the E. coli multicopy vectors type of pUC. Isolation of the hmwDNA from
environmental samples are closely interrelated with the problem of separation DNA from humic
acid. A method developed in our laboratory allows to receive metagenomic DNA of the high
molecular weight which is fitting well with the gene engineering methods. Metagenomic DNA
library is scanned by radioisotope labeled specific DNA probe or analyzed by PCR method.
Synthetic DNA fragments of homologous genes are used as specific DNA probes. DNA primers
for PCR are designed on the basis of alignment of the proteins which are responsible for similar
function in other organisms. Cloned genes are expressed in the yeast heterologous gene
expression system. The results will be presented in more detail during the conference at the
poster session.
environmental
samples
DNA isolation,
humic acid
separation
metagenomic
DNA library
construction
References
1.
2.
J. A. Gilbert, Meth. Mol. Biol., 1, 733(2011)173-183
P. D. Schloss, Genome Biol., 6 (2005)229
screening of
the library
expression of
the gene
67
SYNTHESIS, STRUCTURE AND PHOTOCATALYTIC ACTIVITY OF SOME
MIXED METAL OXIDES
I. Kelpšaitė, S. Mockūnaitė, S. Ostachavičiūtė, A. Šulčiūtė, E. Valatka
Kaunas University of Technology, Radvilėnų pl. 19, LT-50254, Lithuania
E-mail: [email protected]
Photocatalytic and photoelectrochemical solar energy conversion is an actively developing
field of both fundamental and applied research [1–5]. The greatest attention is paid to
photo(electro)catalytic oxidation of organic compounds, water photosplitting and fabrication
of photoelectrochemical solar cells. Among many inorganic semiconductors which were
tested for these purposes, nanoparticulate titania (TiO2) proved to be the most promising
material. However, this oxide exhibits a significant photoactivity only under UV irradiation.
Thus, there is a need for new materials with improved spectral response to the visible light
while keeping good stability in aqueous phase. Moreover, it is necessary to find a suitable
substrate for the immobilization of photocatalysts, as the use of suspensions is related to
additional economic expenses for the separation of catalyst. The electrochemical methods,
such as electrodeposition or electrophoresis, could be cost-competitive for the synthesis of
photocatalytic coatings.
The aim of this work was to synthesize various mixed Ti, Co, Zn, W, Cu oxides with
improved optic, adsorptive and photocatalytic properties, to prepare their coatings on stainless
steel and evaluate possibilities of their practical use in aqueous photoelectrochemical systems.
Zn-Co oxide coatings were prepared by electrochemical deposition under galvanostatic or
potentiostatic conditions. TiO2-based photocatalysts containing various amounts of Cu, Co,
Zn or W oxides were synthesized by thermal decomposition of metatitanic acid impregnated
with metal salts. Some mixed Cu-Co oxides were prepared by sol-gel method, and their
coatings were formed by electrophoretic deposition.
The structure, morphology and composition of the obtained photocatalysts were characterized
by X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy
(SEM), Fourrier transform infrared spectroscopy (FTIR), thermogravimetry-differential
scanning calorimetry (TG-DSC) and atomic absorption spectrometry (AAS). The
photocatalytic activity of the prepared photocatalysts were tested in two model reactions: the
oxidation of methanol and the reduction of Cr(VI) ions in aqueous solutions. The
photoelectrochemical activity of the prepared coatings was investigated by photovoltammetry.
A two compartment photoelectrochemical quartz cell was employed. The anodic compartment
contained the working oxide electrode and Ag, AgCl KCl(sat) reference electrode. The
cathodic compartment held a platinum wire as a counter electrode. 0.1 M K2SO4 solution was
used as a supporting electrolyte. The back side of the working electrode was insulated with
epoxy resin in order to eliminate its contribution to the dark current.
References
1.
2.
3.
4.
5.
G. Colon-Ibanez, C. Belver-Coldeira, M. Fernandez-Garcia, In Synthesis, Properties and Applications of
Oxide Nanomaterials; Eds. J.A. Rodriguez and M. Fernandez-Garcia, John Wiley & Sons, Inc., 2007, p.
491–532.
M. Kitano, M. Matsuoka, M., M. Ueshima, M. Anpo, Appl. Catal. A: Gen., 325 (2007) 1–14.
A. Fujishima, X. Zhang, Comptes Rendus Chimie, 9 (2006) 750–760.
J. Nowotny, T. Bak, M.K. Nowotny, L.R. Sheppard, Int. J. Hydrogen Energ., 32 (2007) 2609–2629.
S. Ito, T.N. Murakami, P. Comte, P. Liska, C. Grätzel, M.K. Nazeeruddin, M. Grätzel, Thin Solid Films,
516 (2008) 4613–4619.
68
Application of environmentally friendly ligands for alkaline electroless
copper plating systems: Electroless copper deposition using isomers of
2,3-hydroxy-1,4-butandicarboxylic acid as Cu(II) ligands
V. Kepenienė, E. Norkus, I. Stalnionienė and G. Stalnionis
Departament of Catalysis, Institute of Chemistry, A. Goštauto 9, LT-01108 Vilnius, Lithuania
E-mail: [email protected]
Many chemical compounds used in technological processes are hazardous for total
environment, therefore the efforts are made to displace those substances with less hazardous
or purely harmless compounds.
2,3-hydroxy-1,4-butandicarboxylic acid (D-, L-, and DL-tartaric acid), forming
sufficiently stable complexes with copper(II) ions in alkaline solutions, was found to be a
suitable ligand for copper(II) chelating in alkaline (pH > 12) electroless copper deposition
solutions [1]. Reduction of Cu(II)-tartrate complexes by hydrated formaldehyde was
investigated and the copper deposits formed were characterized. The thickness of the
compact copper coatings obtained under optimal operating conditions in 1 h reaches
ca. 3 m from 10 to 30 oC temperatures. The plating solutions were stable and no signs of
Cu(II) reduction in the bulk solution were observed. Results were compared to those for
systems operating with other copper(II) ligands [2].
Table. Dependence of copper plating rate ( m) on temperature and pH.
Solution composition (mol l-1): [Cu(II)] – 0.05, [D-, L-, DL–tartrate] – 0.15, [CH2O] – 0.15.
pH
Ligand
t, oC
Plating rate,
μm h-1
0.713
t, oC
Plating rate,
μm h-1
0.849
t, oC
Plating rate,
μm h-1
1.576
10
0.726
20
0.810
30
1.676
D-tartrate
12.0
12.5
13.0
L-tartrate
DL-tartrate
0.950
1.705
2.906
D-tartrate
0.598
0.866
1.844
L-tartrate
10
0.572
20
0.978
30
1.732
DL-tartrate
1.855
1.956
3.018
D-tartrate
0.531
0.939
1.984
L-tartrate
DL-tartrate
10
0.782
0.838
20
1.381
1.369
30
2.392
2.403
References:
1. A. Vaškelis, E. Norkus, I. Stalnionienė, G. Stalnionis. Electrochimica Acta, 49, (2004) 1613-1621.
2. E. Norkus, V. Kepenienė, A. Vaškelis, J. Jačiauskienė, I. Stalnionienė, G. Stalnionis, Donald L. Macalady.
Chemija (Vilnius), 17, N 4 (2006) 20-29.
69
ELECTROCHEMICAL OXIDATION OF CYANIDE
Vilma Keršulytė, Aušra Valiūnienė
Department of Physical Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius,
Lithuania
E. mail: [email protected]
Cyanides are very popular electrolyte, used for metal electroplating, metal ore
processing, chemical and electrochemical applications. After all these processes significant
quantities of cyanides become effluence, which are necessary to be treated. To remove
cyanides from wastewaters there are chemical methods and electrochemical methods, both are
based on cyanides oxidation. Chemical oxidation require the need for chemical additives and
sludge disposal [1-2]. Another choice are methods of electrochemical oxidation [3-5]. Most
advantages of these methods are: there is no need to add to solution any additional chemicals
and during electrolysis heavy metals contained in cyanide electrolytes are collected on
cathode. Therefore during one process we can both destroy cyanides and reduce concentration
of heavy metals. At present the challenge is to find cheap and simple in exploitation method
allowing to get as big as possible efficiencies of cyanide oxidation.
In this work the destruction of free cyanide on platinum, titanium and stainless steel
electrodes has been investigated. All measurements were carried out in 0.1 mol L-1 KCN base
solution also with KCl or CaCl2 additives. The best results were obtained using Pt anode. This
kind of anode allows us to reduce CN- concentration from 0.1 M to 0.06 M during the first
hour of electrolysis at a current density of 200 A m-2, with a current efficiency up to 80%. It
was determined that additives of chloride salts have negligible influence on current efficiency
of cyanide electrooxidation. Further experiments were carried out in order to reduce a price of
cyanide electrooxidation. It was decided to replace platinum electrode by cheaper metal titanium coated with platinum. Using electrodes with different thickness of platinum coat
(100 nm - 1μm) experimentally was determined that at least 400 nm thickness of platinum is
needful for electrochemical oxidation of cyanide. Furthermore, increasing thickness of Pt over
the 400 nm any changes of cyanide electrooxidation rate and current efficiency does not
appear. In order to determine durability of electrodes the electrolysis of cyanide up to 100 h at
a current density of 300 A m-2 were successfully carried out. Consequently, all other
experiments were done using a titanium electrode with 500 nm coat of platinum. Primarily the
influence of temperature on the rate of cyanide electrooxidation was investigated. The
experiments were made in four different temperatures: 10oC, 20oC, 30oC, 40oC. It was
determined that small increase of temperature of the electrolyte allows to increase efficiency
of investigated process and this increasing is most visible in interval between 10oC and 30oC.
However, increase of temperature over the 30oC does not impact the efficiency as it could be
expected. The mixing of electrolyte allows to increase slightly the current efficiencies of
cyanide electrooxidation also.
Summarizing, we can conclude that best results of cyanide electrooxidation were
obtained using platinum anode. Replacing platinum electrode by titanium coated with
platinum allows us to oxidize the cyanide with current efficiencies up to 68% when small
increase of temperature and mixing of electrolyte is applied.
References
1. S. K. Dubey, D. S. Holmes, World J. Microb.Biotechnol. 11 (1995), pp. 257-26.
2. J. R. Parga, S. S. Shukla, F. R. Carrillo – Pedroza, Waste Manage. 23 (2003), pp. 183-191.
3. S. P. Ho, Y. Y. Wang, C. C. Wan, Water Research, 24 (1990), pp. 1317-1321
4. H. Bergman, H. Hertwig, F. Nieber,, Chemical Engineering Processing, 31 (1992), pp. 195-203
5. A. Buso, M. Giomo, L. Boaretto, G. Sandona, A. Paratella, Chemical Engineering Processing, 36 (1997),
pp. 255-260
70
APTASENSORS FOR ALLERGEN LUPIN DETECTION
J. Kirlyte1, P. Nadal2, T. Mairal2, V. Beni2, A. Kausaite-Minkstimiene1,
C.K. O’Sullivan2
1
Centre of Nanotechnology and Material science, Vilnius University, Naugarduko 24, 03225
Vilnius, Lithuania;
2
Nanobiotechnology and Bioanalysis Group, Department of Chemical Engineering,
Universitat Rovira i Virgili, Tarragona, Spain;
E-mail: [email protected]
A sensitive aptamer biosensor based on surface plasmon resonance (SPR) and fluorescence
detection modes for the determination of food allergen lupin was developed. Lupin (Lupine
albus) globulins β-conglutin (Lup an 1) had been added to the list of allergens by International
Union of Immunological Societies (IUIS) in 2008 [1] and all foodstuffs sold in the European
Union containing amounts of lupin must be labeled.
Lup an 1 protein was extracted using centrifugation and isolation by anion-exchange
chromatography methods [2]. The aptamer was used as a molecular recognition element in the
label free SPR affinity analysis and in the competitive signal off fluorescence detection
analysis with complementary oligonucleotide. The aptamer was engineered in a beacon
format labeled with atto 647N at 5‟ extreme and with quencher BBQ-650 at 3‟ end. As
controls were used purified gliadin crude extract proteins (GCE) and -conglutin.
SPR analysis demonstrated aptamer affinity and specificity to Lup an 1 in a range of
quantification between 10 – 70 pM. The fluorescence aptabeacon shows the feasibility of
detecting β-conglutin with high sensitivity. These designed aptasensors provide to have great
applications in food industry due to its high sensitivity and specificity.
1. D.E. Goggin, G. Mir, W.B. Smith, M. Stuckey, P.M. Smith, J. Agric. Food Chem., 13 (2008) 6370-6377.
2. P. Nadal, N. Canela, I. Katakis, C.K. O‟Sullivan, J. Agric. Food Chem., 23 (2011) 2752-2760.
71
ENZYMATIC SYNTHESIS OF 2-ETHYLHEXYL OLEATE
Edita Kleinaitė1, R. Gruškienė1, R. Beliūnas1, I. Matijošytė1 *, B. Tvaska2, S. Grigiškis2,
E. V. Baškys2, M. Kavaliauskė2
1
Vilnius university Institute of Biotechnology, Sector of Applied Biocatalysis,
V.A. Graičiūno str. 8-255, LT-02241, Vilnius, Lithuania,
*E-mail:[email protected]
2
JSC “Biocentras”, V. Graičiūno st. 10, LT-02241 Vilnius, Lithuania; Tel.: +37052661313,
fax.: +37052602454, E-mail: [email protected]
Nowadays the increasing interest is driven by the need to replace the classical methods
in organic synthesis, which are based on stoichiometric reagents, to green eco-friendly
alternatives. The use of biocatalysts in organic synthesis is an attractive alternative which can
lead not only environmental but also economical benefits. Some biocatalysts in comparison
with now used metalo-organic catalysts have a wider range of substrate specificity and better
catalytic properties. The immobilization of biocatalyst helps to optimize the reaction
parameters thereby rendering it more stable and easy to recover and recycle [1, 2].
The purpose of this research was to draw the attention to the pivotal reaction in
organic synthesis – the transesterification reaction whereas the chemical catalysts could be
replaced by biocatalysts - enzymes. The transesterification reaction between methyl esters of
fatty acids and 2-ethyl-1-hexanol (EHO) were investigated. Immobilized lipase Lipozyme TL
IM was selected as the most suitable catalyst for detailed investigation.
It was found that the rate of transesterification was only slightly dependent on
temperature; therefore the temperature in the range of 40-50 °C degrees was proposed to be
the best for efficient transesterification. An experiment of transesterification reaction with
different molar ratios of the reagents showed that excess of 2-ethyl-1-hexanol slows down the
reaction rate, thus, gradual addition of the alcohol may be the optimal choice (Table1). The
experiments on multiple usage of the enzyme indicated that the rate of transesterification
remained nearly unchanged when the same portion of the enzyme was used for three times.
Lipozyme TL IM showed only small enantioselectivity for one of the enantiomers.
Molar ratio of
reagents
Amount of
biodiesel, g
Amount of
EHO, g
LipTL IM, g
Reaction
time, min
Conversion,
%
1 : 1,5
1 : 1,2
1 : 0,9
1 : 0,8
1 : 0,5
89,1
89
85,3
89,1
89,1
59
49
33,8
31,6
19,7
14,8
13,6
12
12,1
10,9
310
330
330
310
180
96,0
97,5
98,1
95,7
99,0
Table 1. The influence of molar ratio between reagents on reaction depth
Furthermore, according to these results we consider that the use of biodiesel in
biocatalytic processes to develop value-added products would be a very attractive solution for
biodiesel production manufacturers in extending their production supply and the potential
sales markets.
References
1.
2.
R.A. Sheldon, Green Chem., 9 (2007) 1273-1283
R. Wohlgemuth, New Biotechnol. 25 (2009) 204-213
72
A CONVENIENT SYNTHESIS AND PROPERTIES OF NIVEL 5,6-DIHYDRO-4HTETRAZOLO-[1,5-a][1,5]BENZODIAZEPINE DERIVATIVES
L. Kosychova, G. Mikulskienė, R. Vidţiūnaitė, I. Bratkovskaja
Vilnius University Institute of Biochemistry, Mokslininku str.12, LT-08662, Vilnius, Lithuania,
E-mail: [email protected]
The synthesis of fused tetrazoles from cycloaddition reaction is well documented [1].
Since tetrazoles have roles in coordination chemistry as ligands, in medical chemistry as antihypertensive, anti-allergic and antibiotic activities and in material science application as
photoraphy and explosives [2]. The action of 1,5 equivalents of sodium nitrite of the
hydrazines 1a-c gave a new 5,6-dihydro-4H- tetrazolo[1,5-a][1,5]benzodiazepines 2a-c,
which yields are very different and depends of molecular electronic density. The structures of
the newly synthesized compounds were confirmed by elemental analysis and IR, 1H and 13C
NMR spectroscopic data [3]. In order to clarify more detail the picture of geometry of
molecules studied, molecular modelling (MM2) was applied for structure investigation.
H2N
N
NH
N
N
N
N
NaNO2 ,H+
R1
R1
EtOH / H2O
N
N
R3
R2
R3
1a R1=Me; R2=H: R3=H
1b R1= H; R2=H: R3= Me
1c R1= H; R2=H: R3= Krb
R2
2a R1=Me; R2=H: R3=NO .Yield= 56%
2b R1= H; R2=H: R3= Me .Yield= 31%
2c R1= H; R2=H: R3= Krb .Yield= 89%
This new conjugated tricyclic 1,5-bezodiazepine system has the fluorescence properties.
2a
500
400
300
500
2b
2c
200
Fluorescence emision
Fluorescence exitation
600
2a
400
2b
300
2c
200
Fig.1. The fluorescence
excitation and emission spectra
of these compounds were
recorded in ethanol. The
observed fluorescence bands
were at 410 – 420 nm, and
excitation 330 – 360 nm.
100
100
0
260 280 300 320 340 360 380
Wavelength, nm
0
360 400 440 480 520 560
Wavelength, nm
References
1.
2.
3.
F. Ek, L-G. Wistrand, T. Freid, Tetrahedron, 59 (2003) 6759-6769.
R. J. Herr, J.Bioorg.Med.Chem., 10 (2002) 3379-3393.
E.Pretsch, P. Bühlmann, C. Affolter, Structure Determination of Organic Compounds, Springer, Berlin,
2000, p. 421.
73
ELECTROCHEMICAL RESPONSE OF SOME ANALYTES AT POLYANILINECOATED PLATINUM ELECTRODE: A COMPARATIVE STUDY
Svetlana Kozlovskaja Gintaras Baltrūnas Albertas Malinauskas
Department of Physical Chemistry, Vilnius University
Naugarduko 24, LT-03225, Vilnius, Lithuania
e-mail:[email protected]
Amperometric responses of biosensor-related analytes hydrogen peroxide, ascorbic acid and
paracetamol have been studied at polyaniline (PANI) modified platinum electrodes in pH 7.0
buffer solution. Covering of a platinum electrode by electropolymerized PANI layer results in
decreased responses both of hydrogen peroxide and paracetamol, depending on the thickness
of a modifier layer. For PANI films having the redox capacity ranging from 5 to 400 C cm2,
nearly 1.5 to 2.1-fold decrease of anodic current response has been obtained both for peroxide
and paracetamol. For ascorbate, adversely, an increase of current response at PANI modified
electrode has been observed due to electrocatalytic nature of this process. It has been
concluded that PANI coatings do not ensure an appropriate electroanalytical discrimination
between the analytes studied.
Fig. 1. Cathodic current response of polyaniline modified electrode to repeating additions of hydrogen peroxide,
ascorbate, and paracetamol (as indicated).
Fig. 2. Dependence of cathodic current on concentration of hydrogen peroxide (A, top), ascorbate (B, middle),
and paracetamol (C, bottom), as obtained at polyaniline modified electrodes.
74
ULLMANN-TYPE N-ARYLATION OF 3-AMINOBENZO[b]THIOPHENES
V. Kriščiūnienė,1 J. Rousseau,1 A. Šačkus,1 P. Rollin,2 A. Tatibouët,2 A. Šačkus1
1
Faculty of Chemical Technology, Kaunas University of Technology, Lithuania
2
ICOA-UMR 6005, Université d„Orléans, France
E-mail: [email protected]
Benzo[b]thiophene derivatives are often present in biologically active compounds.
Namely, they exhibit a variety of properties, as anticancer, anti-inflammatory, anti-allergic as
well as crop protection agents. [1] Closely related heteroarylamino derivatives based on the
benzo[b]thiophene system have attracted attention as a new class of antifungal agents with
remarkable and promising biological properties. [2]
We have focused our interest on the synthesis of a library of C-2 or N-substituted
benzo[b]thiophene pyrimidin-4-one-2-thione derivatives. Applying copper catalysis, further
functionalizations were performed for selective modifications at N.
Ar
NH2
CO2CH3
S
+
Ar
N
NH
Cu
R-NCS
CO2CH3
S
S
N
S
R
O
Several Pd-catalyzed C-N formation methods have been discovered, which, upon using
some sterically hindered phosphine ligands, allowed many coupling reactions of aryl halides
with aminobenzo[b]thiophene-2-carboxylate to proceed under relatively mild conditions and
low temperature. [2] However, industrial use of this method is problematic in many cases due
to the air and moisture sensitivity, as well as the higher costs of Pd catalysts and the relative
ligands. [3]
Here we report mild conditions for Ullmann-type N-substitution on methyl 3aminobenzo[b]thiophene-2-carboxylate involving aryl and heteroaryl iodides. L-proline was
found as excellent promoter for copper coupling reactions. [4] Using this ligand, the CuIcatalyzed reactions afforded the corresponding arylamino derivatives in good yields.
Acknowledgements: Major part of this research was funded by a grand (No. SDS-2010-022)
from the Research Council of Lithuania.
References
1.
2.
3.
4.
M.A. Metwally, M.E. Khalifa, G.A. El-Hiti, J. Sulfur Chem. 31 (2010) 205-223.
E. Pinto & al., Bioorg. Med. Chem. 16 (2008) 8172-8177.
H. Zhang, Q. Cai, D. Ma, J. Org. Chem. 70 (2005) 5164-5173.
D. Ma, H. Zhang, Q. Cai, H. Zhang, Org. Lett. 5 (2003) 2453-2455.
75
IS THE COMPOSITION OF THE BRUSH COPOLYMERS AFFECTED BY THE
RAFT PROCESS?
T. Krivorotova, A. Vareikis, R. Makuška
Department of Polymer Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius,
Lithuania, [email protected]
Reversible addition–fragmentation chain transfer (RAFT) process has emerged as an
important living radical polymerization technique for preparing polymers with controlled
composition for a wide range of monomers and experimental conditions [1].
Bottle-brush polymers with complex macromolecular architecture constituted of hydrophobic
backbone and poly(ethylene oxide) side chains have recently gained considerable attention [24]. Steric repulsion of bottle-brush polymers between the densely grafted side chains
enhances stiffness of the backbone, hinders overlapping and entanglement with neighboring
macromolecules, and promotes ordering.
“Grafting through” strategy was used for the synthesis of brush copolymers in the present
study. Copolymerization of poly(ethylene oxide) methyl ether methacrylate (PEO45MEMA)
as a macromonomer with methacryloyloxyethyl trimethylammonium chloride (METAC) both
by conventional free-radical and by RAFT methods was studied in detail by the use of 1H
NMR spectroscopy for an analysis of residual monomers. S-methoxycarbonyl phenylmethyl
dithiobenzoate (MCPDB) was used as a RAFT chain transfer agent (CTA), and MWD of the
copolymers was determined by SEC with triple detection (RI, LS and viscosity).
In copolymerization with METAC, reactivity of PEO45MEMA was very low resulting in
copolymers with very large composition distribution, and the RAFT process had small effect
on copolymer composition. An analysis of copolymer composition diagrams allowed
concluding that copolymerization of PEO45MEMA and METAC could not be described by
the classical scheme of Mayo and Lewis, i.e. reactivity ratios of the monomers depended on
composition of the monomer feed.
During initial stage of RAFT copolymerization, growing chains are constituted almost
exclusively of METAC units. At high conversions of the monomers, METAC is consumed
(or almost consumed), and homopolymerization of PEO45MEMA takes place. Thus, the
RAFT process leads to gradient brush copolymers of METAC and PEO45MEMA which
structure resemble diblock copolymers., This is in contrast to copolymerization of the same
macromonomer PEO45MEMA with methacrylic acid [5].
Acknowledgement. Financial support from the Research Council of Lithuania under the project MIP50/2010 is gratefully acknowledged.
1.
2.
3.
4.
5.
S. Perrier, P. Takolpuckdee. J. Polym. Sci. Polym. Chem., 43 (2005), 5347-5393.
T. Krivorotova, R. Makuska, A. Naderi, P.M. Claesson, A. Dedinaite, Eur. Polym. J., 46 (2010), 171-180.
S. S. Sheiko, B. S. Sumerlin, K. Matyjaszewski, Prog. Polym. Sci., 33 (2008), 759-785.
H. Lee, J. Pietrasik, S. S. Sheiko, K. Matyjaszewski, Prog. Polym. Sci., 35 (2010), 24-44.
T. Krivorotova, A. Vareikis, D. Gromadzki, M. Netopilik, R. Makuška, Eur. Polym. J., 46 (2010), 546-556.
76
ARYL-SUBSTITUTED CARBAZOLES AS MATERIALS FOR HOLE
TRANSPORTING LAYERS
G. Krucaite1, D. Mazetyte1, V. Jankauskas2, S. Grigalevicius1*
1
Department of Organic Technology, Kaunas University of Technology, Radvilenu plentas
19, LT50254, Kaunas, Lithuania
2
Department of Solid State Electronics, Vilnius University, Sauletekio aleja 9, LT10222,
Vilnius, Lithuania
E-mail: [email protected]
Carbazole-based aryl derivatives will be presented. The derivatives were synthesized for
application as electro-active materials for hole transporting layers. Mono- and diiodoalkylcarbazoles were firstly prepared. The derivatives were reacted by Suzuki procedure with
various boronic acids- phenyl boronic acid, 4 – diphenyl boronic acid, 1-naphtalene boronic
acid, 2,5-tiophenyl diboronic acid and benzene-1,4-diboronic acid, to yield the arylsubstituted carbazoles. All the newly synthesized compounds were identified by mass
spectrometry and 1H NMR spectroscopy. Monoaryl-substituted carbazoles were found to
constitute glasses with glass transition temperatures close to room temperature as
characterized by differential scanning calorimetry. Diaryl-substituted carbazoles demonstrated
higher glass transition temperatures and better film forming properties. The electron
photoemission spectra for amorphous layers of the compounds have been recorded and the
ionization potentials of 5.5-5.8 eV have been established. Room temperature hole drift
mobility in the layers of some compounds molecularly dispersed in polymeric host exceed 105
cm2/Vs at high electric field.
77
HYDRATION OF CYTOCHROME C STUDIED BY FTIR SPECTROSCOPY AND
DSC
J. Latynis, J. Barauskas
Institute of Biochemistry, Mokslininkų g. 12, LT-08662 Vilnius, Lithuania
E-mail: [email protected]
Biological function is possible only in presence of water, which is important for
conformational stability and dynamics of biomolecules [1]. Experimental studies of some
biosystems show that their physiological activity appears rapidly at some critical hydration
level. Most protein folding occurs with water hydrating the peptide backbone and precisely
manoeuvring the backbone through its secondary and supersecondary structural assembly
towards its ultimate and unique active structure [2]. A microscopic understanding of protein
dynamics, i.e., motions of residues and secondary structures, is crucial for our understanding
of protein function. [3] The goal was to investigate structural and thermodynamic behavior of
cytochrome c durig hydration.
It was performed two parallel studies. Fourier Transfer Infrared spectroscopy
secondary structure analysis by amide III vibrational bands showed structural transition
containing 3-14% and lose of beta sheets from 30% weigh procent in protein. Structural
stability is observed from 14 till 30 procent of water in protein. Termodynamic studies of
cytochrome c correlated with spectroscopic studies: during structural transition, enthalpy of
denaturation has minimum and at the 30% - one of the maximum values. At 30% observed
DSC peak of water freezing – “free water”. This is a point when protein become a solution.
alfa
beta
NS
60
7.87
-10
7.48
40
enthalpy (J/g (cit.c.))
Secondary structure (%)
50
14
30
20
-15
-20
-25
10
31.76
87.57
-30
0
0
10
20
30
40
0
50
20
40
60
80
100
water in cytochrome c (%)
Water in cytochrome c (%)
Figure 1. FTIR studied changes in secondary structure Figure 2. DSC studied changes of cytochrome c
denaturation enthalpy during the hydration of protein.
during cytochrome c hydration
References
1.
2.
3.
Oleinikova, A., N. Smolin, and I. Brovchenko. Biophysical Journal, 2007. 93(9): p. 2986-3000.
Chaplin, M. Nature Reviews Molecular Cell Biology, 2006. 7(11): p. 861-866.
Roh, J.H., et al. Biophysical Journal, 2006. 91(7): p. 2573-2588.
78
ANTIMICROBIAL ACTIVITY OF SILVER NANOPARTICLES SYNTHESIZED BY
CAMELIA SINENSIS LEAF EXTRACTS
I. Mačionienė1, J. Šalomskienė1, J. Puišo2, T. Leiliūnas2, A. Guobienė3
Food Institute, Kaunas University of Technology, Taikos av. 92, LT-51180, Kaunas,
Lithuania, [email protected]
2
Department of Physics, Kaunas University of Technology, Studentų str. 50, LT-51368,
Kaunas, Lithuania, [email protected]
3
Institute of Materials Science, Kaunas University of Technology, Savanorių str. 271,
LT-50131, Kaunas, Lithuania, [email protected]
1
Introduction. Nanotechnology is emerging as a rapidly growing field with its application in
science and technology. Biological approaches using microorganisms, fungi, parts of plants or
extracts of plants for metal nanoparticles synthesis have been suggested as a valuable
alternative to chemical and physical methods. The advantage of using plants for the synthesis
of nanoparticles is that they are easily available; safe to handle and possess a broad variability
of metabolites that may aid in reduction. Silver nanoparticles have proved to be most effective
as they had a good antimicrobial efficiency against bacteria, viruses and other eukaryotic
microorganisms. Silver nanoparticles synthesized generated by bioreduction process using
extract of green and black tea leaf (Camelia sinensis), tannic acid and silver nitrate solutions.
The combination of thearubigins, theaflavins, catechins and various phytochemicals present in
tea also serve as excellent stabilizers on nanoparticles and thus, provide robust shielding from
agglomeration.
The aim of this study was to determine antimicrobial activity of silver nanoparticles using
extract derived from green and black tea leaf (Camelia sinensis).
Materials and methods
Biosynthesis of silver nanoparticles was achieved by green chemistry procedure using green
and black tea leaf (Camelia sinensis) extract as a reducing agent. Antimicrobial activity was
determinated by the agar well diffusion method. Test strains of pathogenic microorganisms:
gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC
49452, Bacillus subtilis ATCC 6623), gram-negative bacteria (Salmonella typhimurium
ATCC 14028, Escherichia coli ATCC 25922), and yeast (Candida albicans ATCC 10231)
were used.
Results
The biosynthesized silver nanoparticles demonstrated a good antimicrobial activity against
gram-negative and gram-positive bacteria and yeast. The diameter of inhibition zone that
showed an antimicrobial activity against gram-negative bacteria ranged from 14.5 mm to
16.0 mm, against gram-positive bacteria – from 16.3 mm to 18.0 mm, against yeast – from
12.0 mm to 15.5 mm. Gram-negative bacteria were less susceptible to silver nanoparticles
because the positive charges of the silver nanoparticles interact with the gram-negative
lipopolysaccharide with more affinity than with the gram-positive cellular wall, which is
thought to have fewer interaction sites with positive charges. The good bactericidal activity is
certainly due to the silver cations released from Ag nanoparticles that act as reservoirs for the
Ag+ bactericidal agent.
Conclusions
The biosynthesized silver nanoparticles using Camelia sinensis leaf extracts proved good
antimicrobial activity. The antimicrobial activity is well demonstrated by considerable zone of
inhibition against Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028,
Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 49452, Bacillus subtilis
ATCC 6623, and Candida albicans ATCC 10231.
79
DETERMINATION OF DIBENZO-P-DIOXINS, DIBENZOFURANS AND
DIOXIN-LIKE PCB‘S IN FISH AND MEAT IN LITHUANIA
R. Mašaraitė1, 2, 3, J. Petraitis1, I. Jarmalaitė1, E. Naujalis3
1
National Food and Veterinary Risk Assessment Institute, J. Kairiūkščio str. 10,
LT-08409, Vilnius, Lithuania
2
Natural Science and Technology Center, Chemistry Institute, A. Goštauto str. 9,
LT-01108, Vilnius, Lithuania
3
Natural Science and Technology Center, Semiconductor Physics Institute, A. Goštauto str. 11,
LT-01108, Vilnius, Lithuania
Fish, meat and their products play a significant role in dietary intake of PCDD/PCDF,
that„s why the analytical methods of dibenzo-p-dioxins, dibenzofurans and PCB„s were
developed by HR-GC/MS. Despite very small amounts of these congeners, their toxisity is
very high, so sensitivity and selectivity of analytical methods are very important analysing
samples with HR-GC/MS, because it is possible to achieve concentrations in the level of g-9
(ng) or even g-12 (pg).
Extraction and clean – up of the samples suppose to be the most important goal. As
analytes are lipophylic so the fat content of the sample is determined firstly. Further analysis
is based on the clean – up of fat, fractionating and is made with several columns filled with
different sorbents such as silicagel, florisil, celite and carbon. The amounts of PCDD/F„s are
very small so the cleaning process should be as accurate as possible. Validation was carried
out at the level of interest. Recoveries of internal standarts were achieved 40 – 130 % for fish
and 60 – 120% for meat. Trueness and precision were evaluated on repeatability and
reproducibility conditions (Table 1). Limits of quantification (< 1/5 of maximum limit) and
other validation parameters fulfill requirements that are set out in COMMISSION
REGULATION.
Table 1. Validation data in fish and meat matrixes on reproducibility conditions
(n = 11)
Upper bound PCDD/F‟s (Fish matrix)
Upper bound PCDD/F‟s, DL-PCB‟s (Fish matrix)
Upper bound PCDD/F‟s (Meat matrix)
Upper bound PCDD/F‟s, DL-PCB‟s (Meat matrix)
SD,
pg/g fresh weight
RSD,
(<15 %)
Trueness,
(+/-20%)
3.18 +/- 0.4
7.10 +/- 0.5
0.77 +/- 0.04
3.46 +/- 0.3
12.8
7.4
5.3
7.9
- 6.5
-12.2
1.5
1.3
Fish, meat and their products mostly contain congeners such as
2,3,7,8-tetrachlordibenzofuran, 2,3,4,7,8-pentachlordibenzofuran and polichlorbiphenyls 105,
118 in bigger amounts.
There were analysed 87 fish samples (Baltic herring, Baltic sprats, Baltic salmon, Baltic
cod liver, carp and their products) and 24 animal fat samples (chicken fat, bovine fat, pork fat)
2005 – 2010 in NFVRAI. According the European Commission Regulation, 23 % of fish
samples were found positive that does not meet the requirements concerning
WHO-TEQ(1998)-PCDD/F-PCB.
80
ELECTRODEPOSITION OF Cu-Cr COATING IN THE ACIDIC COPER
ELECTROLYTE WITH METALLIC POWDER OF CHROMIUM
Viktorija Medelienė, Marija Kurtinaitienė
Institute of Chemistry of Center for Physical Sciences and Technology
LT-01108 Vilnius, A. Goštauto 9, Lithuania
Corresponding author: [email protected]
Electrochemical phenomena and materials play an important role in the present-day
technology. Batteries, fuel cells, supercapacitors, electrochromic devices, gas separation
membranes, and sensors are the examples of application of electrochemical materials. The
success in electrochemical technology is largely due to the further design and development of
new electrochemical materials with improved physical and mechanical properties, that meet the
needs of the modern society.
a
b
Fig. 1. SEM image of electrodeposited Cu-Cr coatings vs concentration of
metallic powder of chromium in electrolyte (g .dm-3): 20 (a), 100 (b).
Magnitude: x 5000.
The aim of this paper is to present the data on investigations of electrodeposition of
copper coatings with chromium nanoinclusions in dependance on the amount of a metallic
chromium particles in electrolyte (i), their morphology (ii), their functionality based on their
mechanical properties (hardness, wear resistance) (iii), thermal stability (iiii) as compared to
those of pure copper matrix. It has been discovered that the electrodeposition of copper in an
acidic copper electrolyte with metallic powder of chromium has its peculiarities due to
electrochemical reduction of partially dissolved chromium ions in an acidic medium. The
chromium particles are not chemically inert particles which form copper metal matrix composite,
but thay are an “alloying precursor with chromium”. The polycrystalline Cu-Cr coatings were
electrodeposited in acidic copper sulfate electrolyte containing 20 g.dm-3 of particles of
chromium metallic powder and a smooth-faced Cu-Cr matrix, when the amount of chromium
powder was 100 g .dm-3 (Fig.1). With respect to the increase in smoothness of coating surface the
hardness (HV50) increases from 180 to 240 kgf.mm-2, and shows a significantly higher wear
resistance and more intensive phase transformations of Cu-Cr coating surface at higher
temperatures in nitrogen atmosphere. A meta-stable phases of Cr2N/or CrN were formed at
temperatures higher than 600 o C, which may stabilize matrix of copper coating in nitrogen
atmosphere in contrast to an oxidative degradation of copper coatings in oxygen-containing
atmosphere at higher temperatures. Thus, Cu-Cr coating has more attractive properties as
compared to those of pure copper coating.
81
CONTACT ANGLE MEASUREMENTS OF POLYPROPYLENE MODIFIED BY
Ag2S LAYERS
L. Mikalauskaitė, V. Krylova, R. Alaburdaitė, D. Milašienė
Kaunas University of Technology
Donelaičio str. 73, LT-44029 Kaunas, E-mail: [email protected]
Modification of polymeric surfaces by formation a thin layers of inorganic compounds
including Ag2S has attracted an increasing interest. This is because these composite materials
consisting of polymers with thin semiconductor layer possess various physical and chemical
properties. Due to these properties they can be applied in various fields of science and
technology [1-2]. However, many polymer materials including polypropylene (PP) in their
intrinsic form do not process the surface properties required for their incorporation into
industrial applications. This is mainly due to their poor wettability, poor adhesion and low
surface energy [3].
In this study, deposition of thin Ag2S layers on PP surface was investigated to improve
the surface wettability of this polymer. The substrate material used for chemical bath
deposition (CBD) of thin Ag2S layers was a commercially available PP film of 150 μm
thickness (Proline X998, KWH Plast, Finland). Before modification process the surface of the
PP samples was treated for 25 min at 90 ºC with etching solution (H2SO4/H3PO4 (1:1),
saturated with CrO3). The Ag2S deposition was carried out using a mixture of AgNO3
(0.06 M) and Na2S2O3 (0.2 M) solutions as precursor. Etched PP substrates were immersed
during the deposition process in this mixture solution with pH 2 at 20 °C for 40 min.
Procedure was repeated for 5 times.
Water contact angle (WCA) measurements were carried out at room temperature and
atmospheric pressure using optical measuring equipment. A distilled water drop was released
onto the test substrate surface using a syringe. The drop‟s geometry was acquired by a
numerical camera and transmitted to a computer workstation to calculate the WCA value. All
WCA data were averaged from three measurements with a standard deviation of
approximately 5%. The surface tension s of a solid surface was calculated from the contact
angle of one liquid (water l = 72.8 mJ/m2) [4].
The WCA of the untreated PP was in the order of 104° showing the hydrophobic
behavior of the PP surface. Surface tension s = 20.67 mJ/m2. After PP surface etching, WCA
decreased to 77°, s = 37.36 mJ/m2. Also, etching made hydrophobic PP surface more
hydrophilic. For PP samples coated with Ag2S the WCA also decreased with increasing
immersions time (accordingly the deposited film thickness). Increasing immersions times
from 1 to 5, the WCA decreased from 66 ° ( s = 44.18 mJ/m2) after 1st immersion to 61 °
( s = 47.23 mJ/m2) after 3rd immersion and 56 ° ( s = 50.10 mJ/m2) after 5th immersion.
After etching and further modification PP surface with Ag2S layers became more
hydrophilic, its adhesion properties improved.
References
1.
2.
3.
4.
H. J. Zhai, H. S. Wang, Mater. Res. Bull., 43 (2008) 2354-2360.
Z. Xiaodong, S. Huaqiang, H. Daming, J. Shumin, Mater. Lett., 62 (2008) 2407-2410.
A. Bellel, S. Sahli, Z.Ziari, P. Raynaud, Y. Segui, D. Escaich, Surf. Coat. Technol., 201 (2006) 29–135.
C. A. Ward, A. W. Neumann, J. Colloid Interface Sci., 49 (1974) 286-290.
82
DETERMINATION OF CADMIUM IN FOOD OF ANIMAL ORIGIN BY GRAPHITE
FURNACE ATOMIC ABSORPTION SPECTROMETRY
B. Miliauskaite, A. Jankauskas, J. Sataite, I. Zaikauskiene, I. Jarmalaite, J. Petraitis
National Food and Veterinary Risk Assessment Institute, J.Kairiukscio str. 10, LT-08409
Vilnius, Lithuania
E-mail: [email protected]
A graphite furnace atomic absorption spectrometry (GFAAS) method was established
to determine the amount of cadmium in food of animal origin after the microwave digestion.
Samples were subjected to determination at ashing temperature of 800 ºC and atomization
temperature of 2400 ºC using Pd(NO3)2 as the matrix modifiers. All measurements were
carried out on AA-6800 graphite furnace atomic absorption spectrophotometer (Shimadzu,
Japan) with a hollow cathode lamp. Instrumental parameters: wavelength 228,8 nm, lamp
mode BGC-D2; slit width 0,5 nm; signal processing peak area; sample volume 20 μL; matrix
modifier volume 5 μL; pyrocoated graphite tube with L‟vov platform.
For instrument calibration, 2 μg/L Cd standard was prepared from subsequent
dilutions of 1000 mg/L stock standard (CertiPUR, Merck). A linear working curve could be
obtained between Cd concentration of 0,1-1,0 μg L-1, with a correlation coefficient of 0,999.
ETHOS 900 (Milestone, Italy) was used for the microwave-assisted digestion.
Samples of animal origin were weighed directly into the digestion vessel. Sample weights
were approximately 0,33 grams for fish, meat, mollusks and 0,26 grams for kidney, liver. To
each sample, 3 ml of concentrated HNO3 and 0.5 ml of concentrated H2O2 were added and
microwave assisted digestion is performed. After cooling, the sample solution is transferred to
a plastic vial, and made up to 10 ml. All samples were prepared in duplicate.
This method was validated according to [1], [2] and [3]. Certified reference materials
(CRM) and spiked samples were used for quality assurance. Recoveries of cadmium in frozen
turkey meat (CRL-ISS 14th PT 1st round), freeze-dried fish (CRL-ISS 13th PT 2nd round),
bovine liver (12 PT 2 rd), mussel tissue ERM CE-278, milk powder BCR-151 and spiked
eggs were between 94 and 105 %. In period of 2010 year, were analyzed 84 samples of meat,
73 samples of fish, 34 samples of mollusks, 18 samples of kidney and other different samples.
Cadmium exceeded maximum level in 2 kidney samples and 27 mollusks samples.
Table 1. Limit of detection (LOD), limit of quantification (LOQ) and maximum level (ML) of cadmium
in food of animal origin.
Meat
Fish
Liver
Kidney
Mollusks
LOD, mg/kg
0,001
0,002
0,004
0,051
0,004
LOQ, mg/kg
0,004
0,005
0,014
0,17
0,015
ML, mg/kg
0,050
0,050
0,50
1,0
1,0
Based on validation tests information this method may be successfully used for the
determination of cadmium in food of animal origin.
References
1.
2.
3.
LST EN 14084:2003 Foodstuffs – Determination of trace elements – Determination of lead, cadmium, zinc,
copper and iron by atomic absorption spectrometry (AAS) after microwave digestion
COMMISSION REGULATION (EC) No 333/2007 of 28 March 2007, layng down the methods of sampling
and anglysis for the official control of the levels of lead, cadmium, mercury, inorganic tin, 3-MCPD and
benzo(a)pyrene in foodstuffs
COMMISSION REGULATION (EC) No 1881/2006 of 19 December 2006 setting maximum levels for
certain contaminants in foodstuffs
83
PREPARATION AND CHARACTERIZATION OF VARIOUS STRONTIUM
ALUMINATES
M. Misevičius, G. Degutis, I. Grigoravičiūtė-Puronienė, A. Kareiva
Department of General and Inorganic Chemistry, Faculty of Chemistry, Vilnius University,
Naugarduko st. 24, LT-03225 Vilnius, Lithuania
E-mail: [email protected]
In past years there has been increasing interest in Eu2+ doped strontium aluminates
ceramics because of their long afterglow phosphorescence properties [1]. But most of the
literature deals with the strong green emission ( 530 nm) of Eu2+ in SrAl2O4 with structure of
cubic spinel [2, 3]. Change in the host lattice is regularly used to achieve various emission
colors [4]. In the SrO-Al2O3 system there are four stable double oxides, namely Sr3Al2O6,
SrAl2O4, SrAl4O7 and SrAl12O19 [5].
In the current work the synthesis of various stoichiometric ratio strontium aluminates
including SrAl2O4 (SrO-Al2O3), Sr3Al2O6 (3SrO-Al2O3), SrAl12O19 (SrO-6Al2O3), Sr4Al4O25
(4SrO-7Al2O3), were performed by applying simple aqueous sol-gel process. Appropriate
amounts of Sr(NO3)2 and Al(NO3)3·9H2O were dissolved in 0.2 M acetic acid and stirred for 1
h. In the following step, 1,2-ethandiol as a complexing agent was added to the reaction
solution and stirred for additional 1 h. Then the solvent was evaporated to form xerogel
precursors, which were calcined at temperature range from 700 ºC to 1600 ºC. The structure
of strontium aluminates was determined by X-ray diffraction (XRD) technique. The results
showed, that single phase compounds SrAl2O4 and Sr3Al2O6 were obtained at temperatures of
1200 °C and 900 °C, respectively. Synthesis of other strontium aluminates yielded mixtures
of different crystalline phases. Obtained single phase structures were doped with various
lanthanides such as cerium or erbium/ytterbium. Cerium nitrate dissolved in distilled water
was used as a doping agent in quantities of 1 mol%, 2 mol% and 3 mol%. Er2O3 and Yb2O3
dissolved in nitric acid were used in co-doping strontium aluminates with erbium and
ytterbium at equal molar parts in the range of 1-6 mol%. The photoluminescent properties of
obtained materials are under investigation.
References
1.
2.
3.
4.
5.
D. Haranath, V. Shanker, H. Chander, P. Sharma, J. Phys. D: Appl. Phys. 36 (2003) 2244–2248.
A.J. Lenus, K.G. Rajan, M. Yousuf, D. Somadurai, B. Purniah, Mater. Lett. 54 (2002) 70.
V. Abbruscato, J. Electrochem. Soc. 118 (1971) 930.
T. Aitasalo, J. Holsa, H. Jungner, M. Lastusaari, J. Nittykoshi, J. All. Compd. 341 (2002) 76.
A. Douy, M. Capron, J. Eur. Ceram. Soc. 23 (2003) 2075.
84
INVESTIGATION AND APPLICATION OF IMIDAZOLIUM-BASED IONIC
LIQUIDS IN CAPILLARY ELECTROPHORESIS
A. Orentienė, V. Olšauskaitė, A. Padarauskas
Vilnius university, Department of Analytical and Environmental Chemistry, Naugarduko 24,
LT-03225 Vilnius, Lithuania
E-mail:[email protected]
Ionic liquids (ILs), resulting from the combination of organic cations (e.g., imidazolium,
pyridinium, pyrrolidinium, etc.) and various anions, can be defined as organic salts that are
liquid at or near room temperature, taking 100 °C as arbitrary reference [1]. Scientific interest
in these liquids has started to grow exponentially after discovery of air- and moisture-stable
imidazolium salts in 1992 [2]. There are many factors behind the intense interest in ILs. Some
of these include extended liquid-state temperature range, negligible vapour pressure, high
electrical conductivity, good thermal stability, low flammability and easily tunable physical
and chemical properties by synthetic means. These unique physicochemical properties
contributed to the creation of new technological applications as well as to the improvement of
existing technologies [3]. The intensely increased applicability of ionic liquids will lead to
their industrial production and utilization. Consequently, simple and fast analytical techniques
for the determination of ILs in various matrices will be of great significance. Analytical
methods are also necessary to assess the purity of ILs as well as to determine their physical
and chemical properties. In addition, some properties of imidazolium cations (e.g., positive
charge over a wide pH range, UV absorbance etc.) seem to be very useful for their application
in capillary electrophoretic (CE) separations.
In this study, capillary electrophoresis technique has been investigated for the separation of
imidazolium-based IL cations. In addition, dual-opposite injection CE technique was
evaluated for the rapid separation of both ionic liquid cation and anion in a single CE run.
Finally, the properties of imidazolium cations as cationic UV chromophores, non-covalent
coating agents for fused silica capillaries and carrier electrolyte additives for the separation of
closely related compounds were evaluated.
CE was found to be a good method for the fast separation of commonly used IL cations. The
best separation of cationic constituents of imidazolium ILs was achieved using 50 mmol/L
Tris-phosphate buffer (pH 8.0) as the electrolyte solution. Significant advantage of this
method is the possibility of theoretical prediction of migration times of compounds which
were not analyzed. The CE method was also employed in the determination of commercial
chemical impurities (halides) of ILs.
The addition of 1-alkyl-3-methylimidazolium salt to the electrolyte provided change in the
electroosmotic mobility of the system. Evaluation of the impact of the kind of IL cation on
electroosmotic flow velocity revealed that all imidazolium cations yielded reduced flow, but
cations with longer alkyl chain reduced flow to a larger extent. Finally, we found that adding
imidazolium-based ILs as modifiers in the carrier electrolyte enhanced the separation of
anionic compounds.
Acknowledgements
This work was supported by grant MIP-92/2010 of the Research Council of Lithuania.
References
1.
2.
3.
P. Sun, D.W. Armstrong, Anal. Chim. Acta, 661 (2010) 1-16.
J.S. Wilkes, M.J. Zaworotko, Chem. Commun., 13 (1992) 965-967.
T. Torimoto, T. Tsuda, K. Okazaki, S. Kuwabata, Adv. Mater., 22 (2010) 1196-1221.
85
FORTY YEARS OF MONITORING OF PESTICIDE RESIDUES IN LITHUANIA
J.Petraitis, I.Jarmalaitė, V.Vaičiūnas,
National Food and Veterinary Risk Assessment Institute (NFVRAI), LT-08409,Vilnius, Lithuania
E-mail: [email protected]
Monitoring of pesticide residues in Lithuania started in 1970. During the period 1970 –
1980 main attention was paid to chlororganic pesticides: DDT and its -metabolites, kelthane
(dicofol), hexaclorobenzene, isomers of hexachlorcyclohehane, polychlorpinene, and heptachlor.
Other important control groups were Carbamates, organic mercury compounds, copper residues.
The number of samples of food and water increased to 4000 in 1972 and to nearly 6000 in 1973,
unfortunately only 10 – 15 compounds were analysed. High level of contamination of
environment and feed resulted high level contamination of food of animal origin up to 8.1 %.
From 1950 to 1970, more than 20,000 tonnes of DDT were used annually in the Soviet Union.
According Food Safety issue high contamination of cereals of 2 mg/kg (o, p‟DDT mean
1,2mg/kg; p, p‟-DDT 1, 3 mg/kg) was determined in wheat from Soviet Union [1].
Contamination of food of animal products considerably decreases from 1980 as result of
decreasing of contamination of environment and feeds. Analysis of food of plant origin increase
and exceeded 2000 samples per year. More 600 hundred individual methods for determination of
up 100 pesticide residues in different kind of plant matrixes were prepared. Pesticides with
residues exceeding Maximum residue limits (MRLs) were determined in 1 – 3 % of samples.
The monitoring system was well organised for domestic products to fit planned soviet economy.
Since 1992 farmers started to use the new pesticides. Individual methods for
determination of registered pesticide residues were used for domestic products. Unfortunately
control of imported products was not effective. Contamination of food of animal origin
decreased so since 1994 exceeding of MRLs was not established in products of animal origin.
The new step of control of pesticide residues started in 1998. The multi residue methods
had been developed. Samples were analysed for up 55 to pesticide residues in 1999, the number
ever-increased and reach 310 pesticide residues in 2009. Total number of samples tested for
official control – in period of 1999 -2009 was 4092, fruits and nuts – 1556, vegetables -1870,
cereals - 462, others - 166. 1163 Samples (28.4%) were of domestic origin, 1406 samples
(34.4%) were from other EU countries, 1163 samples (37.2%) were from third countries.
Pesticide residues below MRL were determined in 724 fruit samples (46,2%), 368 vegetables
samples (19.7%), 30 cereal samples (6.5%) and 26 others samples (13.4%). Exceedings of MRL
was determined in 60 fruit sample (3.8 %), 36 vegetable samples (1.9 %), 2 cereals samples
(0.4%) and 2 others samples (1.0%). Exceedings of MRL was determined in apples, grapes,
citrus fruits, pears, plums, peaches, pomegranates, bananas, strawberries, tea cucumbers,
tyomatoes, pepers, aubergines, peas, beans, lettuce, cabbage, carrots, wheat. Pesticides most
commonly exceeding MRL were acephate, acetamiprid, azoxystrobin, boscalide, bromoxynil,
buprofezin, carbaryl, carbendazim, chlorpyrifos, chlorpyrifos-methyl, diazononedemethon-Smethyl, dicofol, dimethoate, endosulfan, ethion, flucitrinate imazalil, lambda-cyhalothrin,
lindane, malathion, parathion-methyl, oxamyl, tecnazene, thiazophos, thiophanate-methyl,
vinclozolin.
References
1. D.Schutz, G.G. Moy and F.K. Kaferstein GEMS/FOOD International dietary survey, WHO,
Geneva, Switzerland, 1974.
86
CELLULOSE/HYDROXYAPATITE COMPOSITES FOR BONE TISSUE
ENGINEERING
O. Petrauskaite, V. Vitkauskas, J. Liesiene
Department of Organic Technology, Kaunas University of Technology,
Radvilenu pl. 19, LT-50254, Kaunas, Lithuania,
E-mail: [email protected]
A. Stumbras, J. Maminskas, G. Juodzbalys
Department of Oral and Maxillofacial Surgery, University of Health Sciences,
Eiveniu str. 2, LT-50009 Kaunas, Lithuania
Cellulose is an abundant renewable, non-toxic and biocompatible polymer. It has similar
mechanical properties compared to hard tissue, but it does not bond directly to bone under
physiological conditions [1]. Thus a direct formation of hydroxyapatite on cellulose surface
was investigated to improve implant bonding abilities to the living bone.
Cellulose gel was prepared by regeneration of cellulose from its acetylated derivatives by the
procedure described previously [2]. In order to make porous cellulose based matrix for bone
tissue engineering gel samples were lyophilized. Photos of scanning electron microscopy
(SEM) showed that sponge structures were fabricated.
Cellulose/hydroxyapatite composites were fabricated mimicking bone mineralization on precalcificated cellulose samples in simulated body fluid (SBF) concentrated by a factor of 1.5
(1.5×SBF). The pre-calcification process of polymer matrix was performed by means of three
different methods: (i) dipping of freeze-dried cellulose samples in phosphate and calcium
solutions; (ii) treating of lyophilized samples with calcium silicate solution that had been aged
for 24 h before use; (iii) treating of carboxymethylated cellulose (amount of carboxyl groups
2.5 mmol/g) matrix with saturated Ca(OH)2 solution.
IR spectra of cellulose samples after mineralization process showed new bands at 602 cm-1
which corresponds to O-P-O bending. The results of X-ray diffraction confirmed the presence
of calcium phosphate, in the form of apatite. After the samples were immersed in 1.5×SBF
solution for 14 days several peaks at 25.8°, 32.1°, 34.1°, 39.6°, 46.7°, 49.6° were detected
which corresponds to the (002), (211), (202), (130), (222), (213) diffraction planes of
hydroxyapatite crystals, respectively.
SEM photos showed that after biomimetic mineralization the surface of cellulose pores was
covered with bone-like apatite layer.
References
1.
2.
P. Cromme, C. Zollfrank, Biomimetic mineralization of apatite on Ca2+ activated cellulose templates.
Material Science and Engineering, 2007, p. 1-7.
A. Maruska, J. Liesiene, A. Serys, Lithuanian Pat. 2299 (1993).
87
FABRICATION OF CARBON NANOTUBES AND COLLOIDAL SILICA
COMPOSITES VIA SOL-GEL PROCESS
J. Pilipavičius, D. Sakalauskas, A. Beganskienė, A. Kareiva
Department of General and Inorganic chemistry, Vilnius University, Lithuania
E. Mail: [email protected]
Carbon nanotubes (CNT) have been widely investigated by researchers to improve
understanding of the unique electric mechanism and optical properties[1]. Semiconducting,
single-walled carbon nanotubes (SWCNT) is a promising material for saturable absorbers in laser
mode locking [2] because of the fast recovery time, which covers a broad spectral range in the
near infrared, and excellent chemical stability. Furthermore, SWCNT-based saturable absorbers
can be fabricated by simple and economical methods, such as spray, spin coating [3] or horizontal
evaporation methods [4].
However, application of those techniques requires dissolution of CNT‟s. Unfortunately,
CNTs are insoluble in any solvents and forming bundles due to strong van der Waals interactions
that tightly hold them together. CNT‟s insolubility decrease the overall yield of usable material
and interfere with most of the desired properties of the CNT‟s [5]. Better CNT solubility can be
reached via chemical covalent or non-covalent modification of tube surface. The use of various
surfactants and polymers can highly increase solubility of CNT in polar and non-polar media.
Currently, fabrication of CNT and polymer composites for saturable absorbers is very
popular and used in laser technology. But, due to nature of organic polymer matrix, these
composites are unstable on higher temperatures or in high energy light expositions. Therefore a
sol-gel process for the fabrication for inorganic (i.e. silica) or semi-organic (organic-modified
silica) matrix can be a promising way to produce photo-chemically and thermally stable CNT
composites: thin/thick coatings, glasses and ceramics
The aim of this work the fabrication of SWCNT‟s and silica composites using spin-coating
technique. So, the SWCNT‟s solubility in ethanol was investigated using different surfactants –
Triton (X-100 and X-305), polyvinylpyrrolidone (PVP 360 000M and PVP 24 000M) and
Poly(4-vinylpyridine) (P4VP 40 000M). The most stable colloidal solution was obtained using a
P4VP as surfactant – solutions were stable up to 6 weeks. Therefore this surfactant was used for
the fabrication of SWCNT/Silica composite coatings. Tetraethyl orthosilicate (TEOS) as silica
precursor and ammonia base as catalyst were used for preparation of colloidal silica
nanoparticles. SWCNT‟s were directly dispensed in the colloidal silica sol and coatings were
made by spin-coating technique. All samples were investigated under optical, atomic force
microscopy methods, and optical non-linearity was measured.
References
1.
2.
3.
4.
5.
Iijima, S. , T. Ichihashi, Nature, 363 (1993) 603-605
Sakakibara, Y., A.G. Rozhin, H. Kataura, Y. Achiba, M. Tokumoto, Jpn J Appl Phys, 44 (2005) 1621
Yim, J.H., W.B. Cho, S. Lee, Y.H. Ahn, K. Kim, H. Lim, G. Steinmeyer, V. Petrov, U. Griebner, F.
Rotermund, Appl. Phys. Lett., 93 (2008) 161106-3
Solodyankin, M.A., E.D. Obraztsova, A.S. Lobach, A.L. Chernov, A.V. Tausenev, V.I. Konov, and E.M.
Dianov, Opt Lett, 33 (2008) 1336-1338
Karousis, N., N. Tagmatarchis, D. Tasis, Chem. Rev., 110 (2010) 5366-5397
88
DISPERSIVE LIQUID-LIQUID MICROEXTRACTION OF DERIVATIZED
PARABENS
A. Prichodko, E. Janėnaitė, V. Vičkačkaitė
Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24,
LT-03225 Vilnius, Lithuania
E-mail: [email protected]
The esters of p-hydroxybenzoic acid (parabens) are effective antibacterial and anti-fungal
agents. Parabens are widely used as preservatives in cosmetics, personal care and
pharmaceutical products and even in foods and beverages, so they are continuously released
in to the environment [1].
Because of the presence of parabens in the environment and their negative effects on human
health there is an increasing interest in their trace analysis. Gas chromatography is one of the
most common methods for parabens analysis. However, since environmental concentrations
of parabens are low it is necessary to perform preconcentration prior to the chromatographic
analysis. Recently introduced dispersive liquid-liquid microextraction [2] is based on ternary
solvent system. A mixture of water-immiscible extraction solvent (as a rule with a higher
density than water) which is dissolved in a water-miscible disperser solvent is injected rapidly
into the aqueous phase. A cloudy solution is formed. It consists of fine droplets of extraction
solvent that are dispersed into aqueous phase. Due to the considerably large surface area of
the finely dispersed extraction solvent, the extraction of the analytes is achieved rapidly.
Following centrifugation, the extraction solvent containing the analytes is sedimented and
analysed by an appropriate method.
Due to their polar nature, prior to GC analysis parabens are often derivatized to reduce their
adsorption in the chromatographic system, to improve sensitivity, peak separation and peak
symmetry. A convenient derivatization approach is in situ acylation by acetic anhydride [3].
The aim of the present work was to develop a simple and rapid dispersive liquid-liquid
microextraction method with in situ derivatization and gas chromatography for the
determination of parabens in water samples.
A dependence of the derivatization efficiency on pH was investigated and it was determined
that derivatization is full at pH>8. The proper pH of the solution was adjusted by addition
0.02 g/ml K2HPO4. The effects of extraction solvent type, extraction and disperser solvents
volume, extraction time and ionic strength of the solution on the dispersive liquid-liquid
microextraction efficiency were investigated. Chlorobenzene containing n-hexadecane as
internal standard was used as an extracting solvent and acetone was used as a disperser
solvent. The calibration graphs were linear up to 10 mg mL-1, correlation coefficients were
0.997 - 0.999, detection limits were 19, 17, 12 and 15 µg L-1 for methylparaben, ethylparaben,
propylparaben and butylparaben, respectively. Repeatabilities of the results were acceptable
with relative standard deviations up to 11 %. A possibility to apply the proposed method for
parabens determination in water samples was demonstrated.
References
1. J.K. Lokhnauth, N.H. Snow, Anal. Chem., 77, (2005) 5938-5946.
2. M. Rezaee, Y. Assadi, M.R. Milani Hosseini, E. Aghaee, F. Ahmadi, S. Berijani, J. Chromatogr. A, 1116,
(2006) 1-9.
3. J. Regueiro, E. Becerril, C. Garcia-Jares, M. Llompart, J. Chromatogr. A, 1216 (2009) 4693-4702.
Acknowledgement
This work has been supported by the Lithuanian State Studies Foundation.
89
THE ELECTROCHEMICAL POLYMERIZATION OF ANILINE ON TITANIUM
AND TITANIUM DIOXIDE
B. Rakovska, A. Malinauskas, A. Valiūnienė
Department of Physical chemistry, Vilnius University
Naugarduko 24, LT-03225 Vilnius, Lithuania
E-mail:[email protected]
Study of electrooxidation of various acids on non- noble metals such as titanium is an
interesting field of research. Titanium anodizing technology is still to be developed. Titanium
can be selected as substrate for electrodeposition of polyaniline because of its good corrosion
resistance and human body biocompatibility [1]. In Ref. [2] authors have reported that when
the working electrode of titanium is anodic polarized, it is easily oxidized giving a nonconducting dielectric film of TiO2 on the electrode surface.
The aim of the present work was to investigate the electrochemical oxidation of Ti in
sulfuric acid and determine the conditions of polymerization of polyaniline on Ti and
electrochemically covered with TiO2 film electrodes.
The layers of TiO2, thickness of 50 – 1000 nm were formed by means of potentiostatic
anodization of titanium electrode in 0.5 M H2SO4 solution. The morphology of the TiO2 films
was characterized by method of the atomic force microscopy (AFM). The results obtained
scanning by AFM electrochemically oxidized Ti surfaces show no clear relationship between
the thickness of TiO2 layer and its roughness. In a common sense, the surface of anodized
titanium becomes more homogeneous with increasing thickness of TiO2 layer. By comparing
the images of anodized and naked titanium surface, and taking into account the roughness
parameters for naked titanium (Rms = 4.1 nm) and anodized titanium (Rms ranging from 1.7 to
3.9 nm), it could be concluded that the sufrace area diminishes to some extent upon
anodization.
Electrochemical formation of polyaniline (PANI) was investigated on both Ti and
electrochemically anodized Ti electrodes in 0.5 M H2SO4 containing 0.05 M aniline solution.
The results obtained using cyclic voltammetry showed that formation of PANI coatings on
titanium electrode occur in the potential range of -0.75 to 1.25 V (vs. Ag/AgCl electrode).
In order to determine whether the electropolymerization of aniline can proceed on the
electrochemically oxidized titanium electrode the cyclic voltammograms were recorded. The
anodic and cathodic current peaks decrease with increasing the thickness of electrochemically
formed TiO2 layer.
The polymerization of aniline on Cu electrode coated with TiO2 by plasma-enhanced
chemical vapor deposition (PE-CVD) was also investigated. The cyclic voltammograms show
that formation of PANI coating on this type of electrode does not occur.
Summarizing, we can conclude that anodizing titanium electrode in 0.5 M H2SO4
solution at the potentiostatic conditions the proper thickness layer of TiO2 can be formed on
the electrode. Furthermore, electrochemically covered with TiO2 electrode is applicable for
polymerization of polyaniline. On the contrary, the formation of PANI does not occur on the
electrode coated with TiO2 by method of PE-CVD.
References
1. Hosseini M, Momeni MM, Faraji M, J Mater Sci.,45 (2010) 2365.
2. Branzoi V, Pilan L, Mol. Cryst. Liq. Cryst., 484 (2008) 303.
90
BLACK PAD PHENOMENON FOUND AFTER THE ELECTROLESS Ni
IMMERSION Au PROCESS
R. Ramanauskas, R. Tarozaitė, A. Selskis, A. Grigucevičienė, A. Kosenko,
J. Juodkazytė
State scientific research institute Centre for Physical Sciences and Technology, Institute
of Chemistry, Potato 9, LT-01108, Vilnius 2600, Lithuania
E-mail: [email protected]
The excessive corrosion of electroless Ni-P (EN) coatings during the subsequent
immersion gold (IG) deposition process often exhibits a grey or black appearance, known
as a “black pad”. Corrosion properties of EN deposits are governed mainly by their P
content and the corresponding structural and mechanical state. With the aim to determine
factors (conditions), which are favorable for enhancement of corrosion resistance of EN
coatings the following activities and studies were carried out: EN coatings with P content
between 3,5 and 11 wt. % were deposited from glycine containing solution and their
thickness, porosity, morphology and corrosion behaviour in a supporting citrate media
were investigated. In order to determine factors (conditions), which are favorable for
deposition of a uniform Au layer of a required thickness (~100 nm) IG was deposited
from KAu(CN)2 solution and further characterization of Au layer thickness, porosity,
quality and morphology was performed. Corrosion behaviour studies were carried out
applying voltammetric and electrochemical impedance spectroscopy (EIS)
measurements, surface morphology examination was performed by scanning electron
microscopy (SEM), while, energy dispersive X-ray spectrometry and X-ray photoelectron
spectroscopy were applied for EN and IG surface chemical composition determination.
Inductively coupled plasma-optical emission spectroscopy was applied for solution
analysis. The thickness of EN and IG coatings was determined gravimetrically and from
SEM data applying Stratagem software. Coatings porosity was evaluated from EIS
measurements.
It was established that the reported characteristics of black pads include the presence
of mud cracks, major/minor spikes, and P enrichment. However, the difficulty of
reproducing black pads out of pure chemicals is a barrier to the understanding of the
phenomenon. Because of the formation of voided layer, the interfacial bonding of solder
to the ENIG plating may be by nature weak even if the EN plating does not suffer from
hyperactive corrosion. Other possible source of weakness of solder joints may be small
voids found at the Ni/Au interface, or impurities introduced during the immersion Au
process, e.g. Cu. Corrosion of the Ni surface is due to its activity in the immersion gold
process. High concentration of citrate (0.4 mol l-1) and the thickness of IG layer
exceeding ~ 80 nm are parameters, which favour the black pad formation.
Inadequate Cu substrate preparation (e.g. inclusions left on the substrate surface)
results in defective EN coating deposition, which could undergo black pad formation.
Acknowledgement: This work was supported by FP7-SME-2008-2-243626-ASPIS
Grant.
91
IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION: A
COMPARATIVE STUDY
I. Razmislevičienė, V. Olšauskaitė, A. Padarauskas
Vilnius university, Department of Analytical and Environmental Chemistry, Naugarduko 24,
LT-03225 Vilnius, Lithuania
E-mail:[email protected]
Dispersive liquid-liquid microextraction (DLLME) is a novel miniaturized sample-enrichment
method developed in 2006 [1]. In this method, water-immiscible extraction solvent dissolved
in a water-miscible dispersive solvent is rapidly injected into an aqueous sample by a syringe.
A cloudy solution containing fine droplets of extraction solvent dispersed entirely in the
aqueous phase is formed. Extraction of the analytes from aqueous sample into the dispersed
organic droplets takes place. After centrifugation, sedimented organic phase is removed using
a microsyringe and analyzed. Simplicity of the operation, speed, low solvent volume, low
cost, high recovery and high enrichment factor are some advantages of DLLME. During the
last two years, ionic liquids have been proposed as extraction solvents in so-called ionic
liquid-based DLLME, and a series of applications, employing the conventional procedure or
some modifications, have been developed [2].
In this work the performance of three ionic liquid-based DLLME approaches, namely solventinduced DLLME, temperature-induced DLLME, and ultrasound-assisted DLLME, was
investigated and compared. Different imidazolium-based ionic liquids were used as the
extraction solvent for the enrichment of four metal complexes with ammonium
pyrrolidinedithiocarbamate and three phthalate esters. Analysis of the extracts was performed
by ultra-performance liquid chromatography (UPLC) on the Waters Acquity UPLC system
(Waters, Milford MA) equipped with an Acquity UPLC PDA detector.
Generally, the extraction efficiency of both analyte groups in ionic liquid-based DLLME was
better than in the conventional DLLME using carbon tetrachloride as extraction solvent. The
enrichment factors ranged from 65 to 103, that are about two times higher than those obtained
by carbon tetrachloride. Finally, there were no statistically significant differences in the
extraction performance by different ionic liquid-based DLLME modes.
Acknowledgements
This work was supported by grant MIP-92/2010 of the Research Council of Lithuania.
References
1.
2.
M. Rezaee, Y. Assadi, M.R. Milani Hosseini, E. Aghaee, F. Ahmadi, S. Berijani, J. Chromatogr. A, 1116
(2006) 1-9.
R. Liu, J. Liu, Y. Yin, X. Hu, G. Jiang, Anal. Bioanal. Chem., 393 (2009) 871-883.
92
CARBON NANOMATERIALS FOR ELECTROCHEMICAL BIOCATALYSIS
J. Razumienėa, I. Šakinytėb, J. Barkauskasb, V. Gurevičienėa, R. Baronasc
Institute of Biochemistry, VilniusUniversity, Moksliniku str. 12, Vilnius 08662, Lithuania
b
Faculty of Chemistry, Vilnius University, Naugarduko 24, Vilnius 03225, Lithuania
c
Faculty of Matchematics and Informatics, Vilnius University, Naugarduko 24, Vilnius 03225,
Lithuania
E-mail:[email protected]
a
Carbon nanomaterials are widely used in bioelectrocatalytic systems, including amperometric
biosensors [1]. These materials are highly attractive due to their unique electronic properties,
biocompatibility, and big variety of forms, which can be tuned to the different enzymecontaining systems. Variety of carbon nanomaterials is yet increasing, since the discovery of
new forms from that group (graphene, nanohorns, nanorings, etc.) is reported.
The aim of this research was to discover carbon materials prospective to be employed in the
third generation reagentless biosensing systems, which are able to operate on the principle of
the direct electron transfer (DET). In this research functionalized single-walled carbon
nanotubes (SWNT) and a few types of graphite nanoparticles have been manufactured and
tested as the electrode material for the amperometric biosensors working with
pyrroloquinoline quinone dependent glucose dehydrogenase (s-PQQ-GDH) from
Acinetobacter calcoaceticus. The SWNT were pre-treated enzymatically using laccase from
Basidiomycete Lac and graphite nanoparticles were obtained as a result of the oxidation in
alkaline media.
It was revealed that using native SWNT or graphite oxide as the electrode materials the DET
effect was not achieved in the biocatalytic systems. This effect can be achieved only in the
presence of oxidized graphite products synthesized in the alkaline media or enzymatically
pre-treated SWNT.
The morphology and the local electric properties of the constituent parts of the biosensors
have been characterized by scanning probe microscopy. The sensitivity and stability are
described for typical types of the biosensors and the mathematical model of their action is
proposed.
Acknowledgements: The work of J. Razumienė and R. Baronas was supported by the European
Social Fund under Measure VP1-3.1-ŠMM-07-K "Support to Research of Scientists and
Other Researchers (Global Grant)", Project "Developing computational techniques,
algorithms and tools for efficient simulation and optimization of biosensors of complex
geometry"
References
1.
C.B. Jacobs, M.J. Peairs, B.J. Venton Anal. Chim. Acta, 662 (2010) 105-127.
93
NEW MEDIATORS FOR BIOELECTROCATALYSIS
J. Razumienė, V. Gurevičienė, E. Čirbaitė, D. Tauraitė, R. Jančienė, A. Palaima,
R. Meškys, V. Razumas
VU Institute of Biochemistry, Mokslinikų 12, LT-08662 Vilnius, Lithuania
E-mail:[email protected]
The implementation of industrially promising biocatalysts, especially oxidoreductases, is
confronted with difficulties concerning availability of efficient redox mediators promoting
an electron transfer between active site of enzyme and electrode surface. A great number
of electron donors or acceptors are known, and are used in chemical technologies,
however many of them suffer of low efficiency or are too expensive for an application in a
bulk synthesis. Thus, there is still a lack of cheap but efficient redox mediators applicable
for enzyme catalyzed redox reactions. In this work, a set of 14 new compounds have been
synthesized and tested as redox mediators applicable for pyrroloquinoline quinone (PQQ)dependent oxidoreductases. The compounds have been synthesized chemically or
enzymatically using laccase from Coriolopsis byrsina GRB13. Synthesis of 2-(4 or 3, or
2-fluorophenylamino)cyclohexa-2,5-diene-1,4-dione was achieved for the first time.
Bioelectrocatalytic systems using the synthesized electron transfer mediators have been
investigated on a base of glucose or ethanol oxidation reactions catalyzed by PQQdependent glucose (PQQ-GDH) and membrane-bound alcohol (m-PQQ-ADH)
dehydrogenases, respectively.
The efficiency of the biocatalytic systems as a factor of electron transfer rate has been
evaluated. The electron transfer from the active site of the enzyme and the electrode
surface via redox conversion of the mediator vary in a wide range (from 0.08(±0.01)×105
A per M of the enzyme active centres for 2-[(2-aminophenyl)disulfanyl]aniline to
2.29(±0.17)×105 A M-1 for 2-(N-methylanilino)-1,4-benzoquinone). Aiming to discover all
essentials for effectiveness of the redox mediators acting in the bioelectrocatalysis, in
parallel with experimental approach, quantum chemical calculations have been applied for
the evaluation of their molecular properties (structure, energy, etc.). The action of the
bioelectrodes was characterized by quantum chemical calculations using density
functional theory with Becke‟s three-parameter exchange hybrid functional combined
with the Lee-Yang-Parr‟s correlation functional (B3LYP). The high level basis set 6311++G** has been used for calculations. Hence, the bioelectrocatalytic systems have
been characterized by experimentally determined kinetic and quantum chemical
parameters.
94
SYNTHESIS AND CHARACTERISATION OF LANTHANIDE DOPED
CADMIUM SELENIDE NANOPARTICLES
1
M. Ruzgytė1, A. Beganskienė1, V. Karabanovas2, A. Selskis1, A. Kareiva1
Vilnius University, Department of General and Inorganic Chemistry, Lithuania.
2
Vilnius University, Institute of Biochemistry, Lithuania.
The development of high-sensitivity and high-specificity probes that lack the intrinsic
limitations of organic dyes and fluorescent proteins is of considerable interest in many areas
of research, from molecular and cellular biology to molecular imaging and medical
diagnostics. Nanometer-sized semiconductor particles have been covalently linked to
biorecognition molecules such as peptides, antibodies, nucleic acids or small-molecule
ligands for application as fluorescent probes. In comparison with organic fluorophores, these
quantum-confined particles (QDs) have unique optical and electronic properties, such as sizeand composition-tunable fluorescence emission from visible to infrared wavelengths, large
absorption coefficients across a wide spectral range and very high levels of brightness and
photostability.
The aim of this study is synthesis, modification and investigation of lanthanide doped
CdSe. The modified cadmium selenide nanoparticles with La2O3, Sm2O3, Eu2O3 and Gd2O3
were investigated using UV/Vis, PL, FTIR and SEM analysis methods. Cadmium oxide and
selenium powder, surfactant - trioctyl phosphine (TOP), and its oxide (TOPO), stearic acid
were used for the preparation of the cadmium selenide nanocrystal. The influence of the
reaction parameters to CdSe nanoparticles size was studied. Cadmium oxide was diluted in
stearic acid at 250-300 °C and added to trioctyl phosphine oxide (TOPO) solution. The
obtained solution was mixed with TOP-Se stock solution to make a raw material solution. The
reaction was stopped, when the particle dimension reached desired size. The optimal reaction
parameters (T = 200 °C, CdO:Se ratio 1:1) were obtained for synthesis highly fluorescence
CdSe nanoparticles. Prepared lanthanide doped CdSe-TOPO coated nanoparticles were
dissolved in toluene or hexane for UV-VIS and fluorescence spectroscopy measurements. The
average particle diameter was estimated from UV-VIS and photoluminescence spectral data.
CdSe semiconductor nanocrystals (2.97 – 4.3 nm) were synthesized.
95
TMSPM/SILICA AND GLYMO/SILICA HYBRID ANTIREFLECTIVE
COATINGS FOR LASER SYSTEMS
D. Sakalauskas, J. Pilipavičius, A. Beganskienė, A. Kareiva
Vilnius University, Department of General and Inorganic Chemistry, Lithuania.
Email: [email protected]
Antireflective (AR) coatings have gained considerable attention for their applications
in optical devices such as solar cells and laser systems [1, 2]. The sol-gel AR coatings consist
of a layer of silica particles that are randomly stacked on the substrate surface. The
interparticle and particle interior porosity decrease the refractive index of the coating to the
square root of the indices of the substrates. The film thickness is easily controlled by varying
the dip-coating or spin-coating speed, sol concentration, and sol viscosity. Also, antireflective
durability and laser damage threshold are very important properties of AR coatings.
In our study, a sol-gel method was proposed to prepare AR silica coatings with
controlled thickness and optical properties by using TMSPM and GLYMO as modifiers.
TMSPM/ and GLYMO/silica sols were prepared by the Stober method [3]. This is the typical
procedure for this simple one-pot reaction. The final concentration of SiO2 was varied from
3% to 5%. The modified SiO2 sols were prepared by adding 0.0028 mol GLYMO /1g or
0.003 mol/1g TMSPM to the colloidal silica suspension. The resultant sols were aged 2 days
in sealed glass containers at room temperature before deposition. All the sols were carefully
filtered through filters before the coating application. The silica sols were deposited on wellcleaned fused silica substrates by dip coating. The coatings were heat treated at 350°C for 4 h.
Transmittance data of obtained coatings confirmed the antireflection behaviour.
Atomic force microscope (AFM) was used for the characterization of surface morphology of
silica coatings. AFM imagines exhibited a direct relation between the surface and morphology
with nature and concentration of modified reagents. The average surface roughness RMS of
GLYMO or TMSPM modified film decreases with the modifier content.
References:
[1]
P. Nostell, A. Roos, B. Karlson Thin Solid Film, (1999), 434, 170-175.
[2]
D. Chen, Material Solar Cell (2000), 68, 313-33.
[3]
W. Stober, A. Fink, J. Colloid Interface Sci. (1968), 26, 62–69
96
ZINC DOPING EFFECTS IN SOL-GEL DERIVED CALCIUM
HYDROXYAPATITE POWDERS AND FILMS
O. Scit1, I. Bogdanoviciene1, E. Garskaite2, R. Ramanauskas3, E. Olsen2, A. Kareiva1
1
Department of General and Inorganic Chemistry, Vilnius University, Naugarduko 24,
LT-03225 Vilnius, Lithuania
2
Department of Mathematical Sciences and Technology, Norwegian University of Life
Sciences, NO-1432 Aas, Norway
3
Center for Physical Sciences and Technology, Institute of Chemistry, A. Gostauto 9,
LT-01108 Vilnius, Lithuania
Calcium hydroxyapatite (CHA) is known to be one of the most important
implantable materials due to its biocompatibility, bioactivity and osteoconductivity coming
from the analogy to the mineral components of natural bones. They can also be used as
florescent materials and radioactive waste disposal matrix. Recently, the sol-gel technique has
been effectively applied for the preparation of CHA [1-4].
Apatites are unique in that they are easily modified due to their property of ease
accommodating foreign ions. The specific luminescence properties of multinary oxides are
highly sensitive to the changes in dopant composition, host stoichiometry, and processing
conditions. However, the CHA has never applied as the matrix for the preparation of
luminescent materials.
In this present work the zinc-doped CHA was synthesized using the same sol-gel
method. The coatings were obtained using dip-coating method. The phase transformations,
composition and micro-structural features in the polycrystalline samples (powder and films)
were studied by infrared spectroscopy (IR), X-ray diffraction analysis (XRD), scanning
electron microscopy (SEM) and energy dispersive X-ray analysis (EDX).
Acknowledgements
O. Scit is grateful for the National Grant from Research Council of Lithuania for Posdoctoral
studies (SF-PD-2010-08-10-0228).
References
1. I. Bogdanoviciene, K. Tõnsuaadu, V. Mikli, I. Grigoraviciute-Puroniene, A. Beganskiene and A. Kareiva.
Centr. Eur. J. Chem., 8 (2010) 1323-1330.
2. I. Bogdanovičienė, A. Beganskienė, A. Kareiva, R. Juškėnas, A. Selskis, R. Ramanauskas, K. Tõnsuaadu
and V. Mikli. Chemija, 21 (2010) 98-105.
3. I. Bogdanoviciene, K. Tonsuaadu and A. Kareiva. Polish J. Chem., 83 (2009) 47-55.
4. I. Bogdanoviciene, A. Beganskiene, K. Tõnsuaadu, J. Glaser, H.-J. Meyer, A. Kareiva. Mater. Res. Bull., 41
(2006) 1754–1762.
Keywords: calcium hydroxyapatite, CHA, sol-gel method, dip-coating method.
97
FORMATION AND CHARACTERIZATION OF SPRAY PYROLYSED
TRANSPARENT CONDUCTIVE FLUORINE-DOPED TIN OXIDE FILMS
B. Šebeka, I. Savickaja, J. Juodkazytė, A. Selskis
Center for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9,
LT-01108, Vilnius
E-mail: [email protected]
Layers of conductive transparent oxides like indium tin oxide (ITO) or fluorine-doped
tin oxide (FTO) are widely used as transparent contacts in the production of solar energy
conversion and optoelectronic devices [1]. Various vacuum evaporation techniques are
usually used for the formation of such layers [2]. These techniques are quite expensive and,
moreover, the surface area of the substrate, which can be coated using these methods, is
relatively small. In order to increase the surface area of the substrate to be coated and to
reduce the production costs, chemical methods of the formation of conductive transparent
oxide layers are sought. Fluorine-doped tin oxide (SnOx:F) is the most resistant and is
characterized by the best chemical durability as far as its possible applications as a substrate
material for electrochemical modifications are concerned. For this reason FTO is preferred to
ITO, despite of its higher electrical resistivity [3].
We have investigated the possibilities to form transparent conductive FTO layers of
various compositions on glass substrate using the method of spray pyrolysis. Among the
various deposition techniques, spray pyrolysis is well suited for the formation of doped tin
oxide thin films because of its rather simple and inexpensive experimental arrangement.
Inorganic Sn salts and fluorides were used as precursors. The solutions were stabilized using
various organic tin-complexing agents. Argon was used as a carrier gas. The temperature of
SnOx:F films deposition ranged from 430 to 480 oC.
Light transmittance, T (%), of FTO films was measured within 270 – 1100 nm range
using Perkin Elmer Lambda 35 UV/VIS spectrophotometer. The resistivity of SnOx:F layers
was measured with ohmmeter between the opposite sides of a surface square. It was found
that both transmittance and resistivity of the films depended on their thickness and formation
temperature. The optimal results were obtained for FTO layers spray-deposited at 460 - 470
o
C: T = 80 86 % (at 400 500 nm) and R = 14 17 /□. The thickness and elemental
composition of SnOx:F films was determined using scanning electron microscope with energy
dispersion and wave dispersion X-ray spectrometers. The film thickness ranged from 200 to
350 nm.
Spray-deposited fluorine-doped tin oxide films were found to be chemically resistant
to inorganic acids. Voltammetric behavior of FTO layers in acid and alkaline solutions was
also investigated.
References
1. C. Agashe, J.Hüpkes, G.Schöpe, M.Berginski, Sol. Energy. Mater. Sol. Cells, 93 (2009) 1256–1262.
2. J. H. Park, D. J. Byun, J. K. Lee, J. Electroceram, 23 (2009) 506–511.
3. A. A. Yadava, , E. U. Masumdara, A. V. Moholkarb, K. Y. Rajpureb, C. H. Bhosaleb, Physica B: Condensed
Matter, 404 (2009) 1874-1877.
98
PHOTOELECTROCHEMISTRY OF MoO2|SnO2|GLASS ELECTRODE IN
AQUEOUS SOLUTIONS
D. Sinkevičiūtė, N. Dukštienė
Kaunas University of Technology, Radvilenų pl.19, 50254, Kaunas, Lithuania
E-mail: [email protected]
In past few years, electrolytic molybdenum oxide films have been investigated widely as a
promising material because of low cost, high electrochemical activity and more friendly
environmental nature than other transition metal oxides [1, 2].
Recently [3] we have reported on the electrodeposition of thin MoO2 films on the Se predeposited SnO2|glass surface. Herein we continue our previous investigations and the purpose
of present study was to investigate the photoelectrochemical behavior of MoO2|SnO2|glass
electrode in aqueous solutions with different pH.
Photoelectrochemical measurements were carried out with a three compartment quartz cell
using a coputer-controlled Autolab PGSTAT12 (Ecochem, the Netherlands)
potentiostat/galvanostat. A UV lamp (F8W/BLB, General Electric) was used as an irradiation
source. The calculated average power density at = 366 nm was 1.8 mW·cm-2.
The photoelectrochemical behavior of MoO2|SnO2|glass electrodes was determined from
current potential curves, recorded both in the dark and under irradiation (Fig.1). In all
solutions the photopotential shift was negative and photocurrents were predominantly anodic,
thus indicating n-type bulk semiconducting behavior of MoO2|SnO2|glass electrodes.
Fig.1 Voltammograms of MoO2|SnO2|glass electrode
recorded in the dark (1) and under UV irradiation (2)
in solution with 6.3 pH. v = 2 mVs-1, t = 20 oC.
Fig.2 Voltammograms of MoO2|SnO2|glass electrode
recorded under UV irradiation in solution with different
pH: 1.6 (1) and 3.1 (2). v= 2 mVs-1, t = 20 oC.
However the shape of voltammograms under irradiation is pH dependant (Fig.1 and Fig.2).
In acidic solutions pronounced anodic current peak is observed. After the peak potential
current suddenly drops down and at above 0.5 V levels to a constant value. Such current
potential characteristics are typical for passivating behaviour of electrode. Contrary,
MoO2|SnO2|glass electrode is stable in pH 6.3 solutions (Fig.1), but generated photocurrents
are rather small. The results showed that the highest calculated IPCE value was in pH 3.1
solutions.
The photoelectrochamical stability of MoO2|SnO2|glass composite was evaluated by the
scanning electron microscopy and Fourier transformed infrared spectroscopy techniques.
References
1.
2.
3.
H. Farsi, F. Gobal, H. Raissi, Sh. Moghiminia, J. Solid State Electrochem., 14 (2010):643-650.
E. Shembel, R. Apostolova, V. Nagirny, I. Kirsanova, Ph. Grebenkin, P. Lytvyn, J. Solid State
Electrochem., 9 (2005) 96-105.
D. Sinkeviciute, J. Baltrusaitis, N. Dukstiene, J. Solid State Electrochem., 15 (2011) 711-723.
99
MATRIX INDUCED DIFFERENCES IN LUMINESCENCE PROPERTIES OF
LANTHANIDE-DOPED OR LANTHANIDE-SUBSTITUTED MIXED-METAL
GARNETS SYNTHESIZED BY SOL-GEL METHOD
Ramunas Skaudzius, Aivaras Kareiva
Department of General and Inorganic Chemistry, Vilnius University, Naugarduko 24, LT03225 Vilnius, Lithuania
E-mail: [email protected]
Yttrium aluminum garnet (YAG) shows exceptional chemical stability and therefore doped or
substituted with Ce3+, Eu3+, Tb3+, Cr3+, Sm3+, Dy3+ or Tm3+ is employed as the host material
of multicolored phosphors. By selecting corresponding lanthanide ions may be produced red,
green and blue (RGB) emission for use in tricolor white light [1-3]. It is known that the
chemical composition of host material influences of optical properties of such phosphors
considerably [4]. The matrixes of garnets could be modified by replacing different molar part
of aluminum or gallium by other metals in YAG. Therefore, in the present work the
sinterability, microstructural and luminescence properties evolution of lanthanide-doped
mixed-metal Ce:Y3Al5-xInxO12 (1.50
x
L:Y3Al5-xInxO12 (L = Ce, Eu, Er and Tb; 1.50
2.25) and lanthanide-substituted mixed-metal
x
2.25) garnets powders synthesized by an
aqueous sol-gel process were investigated. The gels were prepared using stoichiometric
amounts of analytical-grade Y2O3, Al(NO3)3·9H2O, In2O3, Ce(NO3)3·6H2O, Eu2O3, Er2O3 and
Tb2O3 as starting materials.
The synthesized samples were characterized by UV-visible, infrared spectroscopy, X-ray
diffraction analysis, TG/DTA analysis and emission spectra. Scanning electron microscopy
was used to study the morphology and microstructure of the ceramic samples. The tentative
investigations of optical properties of synthesized lanthanide-doped and lanthanidesubstituted mixed-metal garnets showed that their luminescence is slightly dependent on the
chemical composition of matrix. These mixed-metal garnets doped with lanthanide ions could
be potential candidates for the development of new luminescent materials.
References
1.
2.
3.
4.
W.T. Hsu, W.H. Wu and C.H. Lu, Mater. Sci. Engin., 104 (2003) p.40.
A. Katelnikovas, P. Vitta, P. Pobedinskas, G. Tamulaitis, A. Ţukauskas, J.E. Jorgensen, A. Kareiva, J.
Cryst. Growth., 304 (2007) p.361.
P.F.S. Pereira, M.G. Matos, L.R. Avila, E.C.O. Nassor, A. Cestari, K.J. Ciuffi, P.S. Calefi and E.J. Nassar,
J. Lumin., 130 (2010) p.488.
A. Katelnikovas, H. Bettentrup, D. Dutczak, A. Kareiva, T. Jüstel, J. Lumin., (2011) 10.1016.
100
PRODUCTS CYCLIZATION OF 2-{[1-(4-METHOXYPHENYL)-5OXOPYRROLIDIN-3-YL]CARBONYL}HYDRAZINECARBOX(THIO)AMIDES
1
E. Slaninaitė1, V. Mickevičius1, G. Mikulskienė2
Kaunas University of Technology, Radvilenu pl. 19, LT-50254, Kaunas, Lithuania, E-mail:
[email protected]
2
Vilnius University Institute of Biochemistry, Mokslininku str.12, LT-08662, Vilnius,
Lithuania, E-mail: [email protected]
The target thiadiazole and triazole derivatives 3,5,6 were prepared fom the respective
carboxamide 2 or carbothioamide 4 in alkaline or acidic media as illustrated in Scheme. The
starting compounds 2,4 were synthesized by refluxing the corresponding carbohydrazide 1
with phenyl isocyanate or phenyl isothiocyanate in methanol. It is known that the 5oxopyrrolidine cycle is not resistant to alkaline hydrolysis. In the present work, sodium salt of
substituted butanoic acid was formed by decomposition of the pyrrolidinone cycle of
compound 4 in refluxing 20 % solution of sodium hydroxide. Acidification of the aqueous
solution of this salt gave stable 3-substituted 4-arylaminobutanoic acid 7.
O
CH3O
O
2 % NaOH,
CH3O
3h
O
N
NH
2
N
N
NH
NH
3
O
NH
N
PhNCO,
CH3OH, 6 h
O
O
O
CH3O
PhNCS,
CH3OH, 6 h
N
CH3O
S
N
NH
NH
1
NH
NH2
4
O
H2SO4,
r. temp., 1h
O
NH
O
1) 20 % NaOH, 3 h
2) 3N HCl
2 % NaOH,
3h
OCH 3
N
N
H
N
N
O
N
5
N
HO
7
N
6
NH
3N HCl
N
CH3O
HN
S
CH3O
S
NH
O
N
S
The resonances at 160.45 ppm and 164.54 ppm in 13C NMR spectra pointed to the formation
of 5-membered thiadiazole ring in compound 5 [1-2]. The conversion of compound 4 into 6
proved by the appearance of NH singlet at 13.89 ppm in 1H NMR spectra, and absence other
resonances in the NH region. In addition, the characteristic resonances at 152.88 ppm and
168.39 ppm, assigned to the C=N and C=S carbons, respectively, acknowledged the existence
of compound 6. The formation of open structure [3] instead of pirolidinone ring in compound
7 was confirmed by presence of NH resonance at 5.48 ppm in 1H NMR spectra and COOH
group carbon resonance at 173.08 ppm in 13C NMR spectra.
References
1.
2.
3.
K. Anusevičius, V. Mickevičius, G. Mikulskienė, Chemija, 21 (2010) 127-134.
V. Mickevičius, R. Vaickelionienė, I. Jonuškienė, G. Mikulskienė, K. Kantminienė, Monatsh. Chem., 140
(2009) 1513-1522.
M. Mickevičius, Z.J. Beresnevičius, V. Mickevičius, G. Mikulskienė, Heteroatom Chem., 17 (2006) 47-56.
101
DETERMINATION OF ORGANOTIN COMPOUNDS IN WATER USING
GC-MS WITH SELECTED ION RECORDING
Vaida Šmitienė, Vida Vičkačkaitė
Department of Analytical and Environmental Chemistry, Vilnius University,
Naugarduko 24, LT-03225 Vilnius, Lithuania. E-mail: [email protected]
Organotin compounds (OTCs) are used mainly as heat- and light stabilizing additives for
plastics like polyvinylchloride, as biocide agents (e.g. anti-fouling paints for ship hulls, in
pesticides, as wood preservatives) and as polymerization-catalyst (polyurethane foam) [1].
Some of the OTCs are extremely toxic to living organisms. For example, tributyltin and
tripropyltin are most toxic towards marine organisms; tributyltin and triphenyltin have been
identified as endocrine disruptors. The toxicity of organotin compounds increases with the
increase of the number of organic functional groups attached to tin.
Due to their widespread use organotin compounds are present in biota, marine water and
sediments including those in deep-sea environments worldwide at levels which are harmful to
some marine organisms [1]. Because of their toxicity and bioaccumulation potential, OTCs
have been registered as priority pollutants by European Union in the Pollutant Emission
Register (2000/479/EC) and in the Water Framework Directive (2000/60/EC) [2].
Several methods for the analysis of OTCs have been described. Most of them are based of
hyphenated techniques using liquid and especially gas chromatography [3].
In this work, capillary gas chromatography and MS detection with selected ion recording was
applied for OTCs determination. Prior to GC analysis OTCs should be derivatized. The
derivatization reactions most commonly used for OTCs are hydride generation with sodium
borohydride, ethylation with sodium tetraethylborate (NaBEt4) and alkylation with Grignard
reagents [3]. In this work, ethylation using NaBEt4 followed by liquid-liquid extraction was
developed. An optimum pH for the ethylation was determined to be 4 -5, thus the
derivatization procedure was carried out at pH 4.5 that was adjusted using acetic acid/sodium
acetate buffer. Hexane as an extraction solvent was selected and its volume was optimized. An
optimal extraction time was determined to be 20 min.
Accurate organotin determination requires the use of appropriate internal standards in order to
alleviate matrix effects and systematic errors during the sample preparation step. Tripropyltin,
tricyclohexyltin and deuterated organotin compounds are most frequently used as internal
standards for GC-MS [4]. In this work, tripropyltin and tetrapentyltin were tested.
Tetrapentyltin gave more reproducible results thus it was selected as an internal standard.
The precision, linearity, detection limits of the method were determined.
The suggested technique was applied for organotin determination in drinking, surface, waste
and sea water samples. The concentrations were determined by calibration over the total
procedure using an internal standart.
Acknowledgement
This work has been supported by the Lithuanian State Science and Studies Foundation.
References
1. N. M. Tzollas, G. A. Zachariadis, J. Sep. Sci., 33 (2010) 1610-1616.
2. T. Zuliani, G. Lespes, R. Milačič, J. Ščančar, Talanta, 80 (2010) 1945-1954.
3. E. Magi, C. Liscio, M. Di Carro, J. Chromatogr. A., 1210 (2008) 99-107.
4. C. Devos, M. Vliegan, B. Willaert, F. Davida, L. Moens, P. Sandra, J. Chromatogr. A., 1079 (2005) 408414.
102
ELECTROCHEMICAL CHARACTERIZATION OF SPUTTER-DEPOSITED Mg-Nb
ALLOYS
L. Staišiūnas, A.Grigucevičienė, K. Leinartas, P. Miečinskas, R.Juškėnas, P.
Kalinauskas, E. Juzeliūnas
Centre for Physical Sciences and Technology, Institute of Chemistry, A. Goštauto 9, 01108
Vilnius, Lithuania; E-mail: [email protected]
Magnesium co-deposition with Nb is of interest to get systems, which linked up the lightness
of magnesium and the corrosion resistance of the alloying additive. Niobium is a valve metal,
which reacts readily with water or oxygen and forms dense and highly protective oxide layer.
Magnesium is the lightest metal, which is susceptible to pitting or exfoliation corrosion due to
low protective capability of (hydro)oxide film. Formation of Mg-Nb alloys is complicated
because the melting point of Nb exceeds far the boiling point of Mg; Nb does not form binary
phases with Mg and shows negligible solubility in it [1]. Such a binary system, however, can
be deposited from a gas phase by evaporation of metals from different crucibles or cosputtering different targets. Sputtering provides an opportunity to supersaturate a single phase
with a metal of limited solubility. For instance, supersaturation of a single phase Mg-Al-Zr
was achieved up to 15 at. % of Zr, while its solubility in magnesium is 1 at.% [2].
Thin films of Mg-Nb alloys were deposited by DC magnetron sputtering (UNIVEX 350,
Leybold) in a wide range of Nb concentrations from 6 at. % to 80 at.%. The SEM microprobe
("EVO-50 EP", Carl Zeiss SMT AG) and XRD (“D8 Advance” diffractometer, Bruker AXS)
methods were used to evaluate composition and structure of the deposits. The DCvoltammetry and Electrochemical Impedance Spectroscopy (EIS) measurements (P/G/FRA
Model 2273, Princeton Applied Research) in chloride and chloride-free borate solutions
showed high corrosion resistance of the alloys when Nb content in the alloy was one third or
more. Semiconductor properties of spontaneously formed oxide on Mg-Nb were studied by
EIS Mott-Schottky plots and photo-electrochemistry methods. The obtained data show that
the spontaneously formed niobium oxides are highly doped and non-stoichiometric. It can be
mentioned that for as-prepared Mg-Nb patterns any or very slight p-type photo-response was
determined. At the same time prolonged exposure of alloys in borate solutions or especially
its anodizing lead to formation of distinct n-type semiconductor layers. For an n-type oxide
the doping comes from the defects due to predominating oxygen vacancies. It is quite
understandable that the spontaneously developed oxide during sample exposure in atmosphere
could have some oxygen concentration gradient: the area close to the interface oxide/air will
contain more oxygen than the area close to metal/oxide interface. In spite of great number of
defects, the oxides exhibit high protective capability provided content of Nb is sufficient, i.e.
some 30% and more. These alloys as film coatings are of interest in practical magnesium
protection (for instance, in biomedical materials), because Mg can promote adhesion on
parent metal and Nb can create an effective barrier from aggressive environment.
References
1. A.A. Nayeb-Hashemi, J.B. Clark (Eds.) Phase Diagrams of Binary Magnesium Alloys, ASM International,
Materials Park, OH 44073, 1988.
2. A. Grigucevičienė, K. Leinartas, R. Juškėnas, E. Juzeliūnas, Mat. Sci. Eng. A, 394 (2005) 411-416.
103
Cu(II) COMPLEX FORMATION WITH PENTAETHYLENEHEXAMINEDETERMINATION OF STABILITY CONSTANTS USING THE LIGAND
DISPLACEMENT METHOD
I. Stankevičienė, A. Jagminienė, E. Norkus, K. Prušinskas
Center for Physical Sciences and Technology, Institute of Chemistry,
A. Goštauto 9, LT-01108 Vilnius
E-mail: [email protected]
Diamines or higher amines found application as copper(II), cobalt(II) and cobalt(III)
ligands in the novel systems of electroless copper deposition, where Co(II) complexes act as
reducing agents [1-5]. Probably, pentaethylenehexamine (penta), also can be applied as
Cu(II), Co(II) and Co(II) ligand in the systems for electroless copper deposition.
Cu(II) ions form (pH 7) 1:1 and 1:2 complexes with pentaethylenehexamine (penta),
depending on excess of penta. The spectrophotometric method of ligand displacement was
applied for determination of the stability constant of mentioned complexes using EDTA as
competitive ligand. The results obtained are in agreement with the 1:1 and 1:2 stoichiometry
of the complexes, namely Cupenta2+ and Cupenta22+, the stability constant logarithms being
21.1 and 29.8, respectively (Table 1 and Fig.1).
Absorbance
Table 1. Data on equilibria in the system Cu(II)-pentaethylenehexamine(penta)-EDTA calculated from the
spectrophotometric data of Fig. 1 ( Cu(II)-penta molar ratio 1:2). [Cu]0 = 0.005 M; pH = 7; 20 °C.
[EDTA]0 * [CuY2-] *[Cupenta22+]
[penta]
[Y4-]
[Cu2+]
log
M
M
M
M
M
M
Cupenta22+
0.001
0.000713
0.004287
9.2285E-10
1.07806E-07
3.99849E-16
30.8
0.002
0.001339
0.003661
1.73349E-09
2.48189E-07
8.71659E-16
30.2
0.003
0.001882
0.003118
2.43502E-09
4.20247E-07
7.11202E-16
29.9
0.004
0.002495
0.002505
3.22845E-09
5.65627E-07
6.99437E-16
29.5
0.005
0.00244
0.00256
3.15828E-09
9.61728E-07
4.02244E-16
29.8
0.007
0.002758
0.002242
3.56905E-09
1.59393E-06
2.74326E-16
29.8
0.008
0.00366
0.00134
4.73669E-09
1.63067E-06
3.55967E-16
29.2
0.010
0.003501
0.001499
4.53091E-09
2.44187E-06
2.27274E-16
29.5
0.015
0.003918
0.001082
5.07094E-09
4.16374E-06
1.4918E-16
29.4
Mean: 29.8 0.5
* Averages of the values calculated at 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690,
700 nm wavelengths.
Fig.1. Cu(II) light absorption spectra in penta solutions (1), EDTA(11) and their mixture (2-10). Solution
composition (M): [Cu(II)]0 – 0.005; [penta]0 – 0.01; [EDTA]0: 1-0; 2-0.001; 3-0.002; 4-0.003; 5-0.004; 6-0.005;
7-0.007; 8-0.01; 9-0.008; 10-0.015. Solution pH – 7; 20 C
1.0
References
1
1. A. Vaškelis, J. Jačiauskienė and E. Norkus,
2
Chemija, N 3, 1995, p. 16.
0.8
3
2. A. Vaškelis, E. Norkus, G. Rozovskis, and J.
4
Vinkevičius, Trans. Inst. Metal Finish., 75, 1997.
0.6
5 6
3. A. Vaškelis and E. Norkus, Electrochim. Acta, 44,
7
1999, p. 3667.
8
9
0.4
4. A. Vaškelis, A. Jagminienė and I. Stankevičienė,
10
Electrochim. Acta, 51, 2006, p. 2215.
11
0.2
5. A. Vaškelis, I. Stankevičienė, A. Jagminienė, L.
Tamašauskaitė Tamašiūnaitė and E. Norkus. J.
Electroanal. Chem., 622, 2008, p. 136.
0.0
400
600
800
1000
nm
104
SYNTHESIS OF PYRIMIDINE DERIVATIVES BY SONICATION AND
TRADITIONAL HEATING METHODS
Ţ. Stankevičiūtė, A. Jančauskaitė, V. Gefenas
Vilnius Pedagogical University, Studentų 39, LT–08106 Vilnius, Lithuania
E-mail: [email protected]; [email protected]
Green chemistry has become a major driving force for organic chemists to develop
environmentally benign routes for the preparation of organic compounds. Many organic
reactions have recently been accelerated by one of the green synthetic method – ultrasonic
irradiation [1,2]. A particularly attractive approach is based on ultrasound-promoted
heterocyclization reactions of suitably functionalized substrates [2].
In this work 5-cyano-2-methylsulfanyl-4(3H)-pirimidinone (3) and furo[2,3-d]pyrimidines
6a,b were synthesized from ethyl (E)-2-cyano-3-(S-metilizotioureido)-2-propenoate (1) and
4-(p-halophenacyloxy)-2-methylsulfanylpyrimidine-5-carbonitriles (5a,b), respectively, using
thermal and sonochemistry (35 and 130 kHz) methods. Reaction of compound 1 gives a
complex mixture of cyclization (compounds 2 and 3) and hydrolysis (compounds 4a,b)
products [3]. Alkylation of pyrimidinone 3 with p-halo -bromoacetophenones occurs to give
carbonitriles 5a,b [4], which undergo ring closure to form furopyrimidines 6a,b [5].
NH2
COOC2H5
N
5–10
2
oC
CH3S
H2NC(SCH3)=N
50–55
H
oC
or US / r.t.
CN
H
CO2C2H5
1
+
NH2C(O)NH
1. 0.5M MOH
(M = Na, K)
CN
N
CO2C2H5
4a
+
2. HCl or
CH3COOH
NH2
N
CH3S
N
0–2
oC
R
O
6a,b
a
CN
H
NH2C(O)NH 4b CO2C2H5
+
CN
N
O
CH3S
N
H
C
N
N
_
R
C2H5ONa / C2H5OH
C
N
O
3
R
N
or US / r.t.
CH3S
N
O Na+
CH3S
O
5,6 a R = Cl, b R = Br
N
O
5a,b
a
O
The product distribution in both cyclization reactions depends on quantity of base and
initiation method. Application of ultrasound shortened the reaction time of the generation of
pyrimidines 6a,b. While with thermal heating reactions of furopyrimidines 6a,b synthesis
required heating at reflux for 8 h, the new method was performed at room temperature for 1–3
h. These reactions were realized under milder conditions and the yields of the products 3 and
6a,b were improved by 10–30 % in comparison with those obtained by the thermal heating
methods.
References
1. E. Ruiz, H. Rodriguez, J. Coro et al., Ultrasonics Sonochemistry, 18 (2011) 32-36.
2. R. Cella, H. A. Stefani, Tetrahedron, 65 (2009) 2619–2641.
3. V. Gefenas, Ţ. Stankevičiūtė, A. Malinauskas, S. Tumkevicius, Khim. Geterotsikl. Soedin., (2010) 456–459.
[Chem. Heterocycl. Comp., 46 (2010) 363–365].
4. V. Gefenas, Z. Stankeviciutė, A. Malinauskas, Khim. Geterotsikl. Soedin., (2009) 1754–1756. [Chem.
Heterocycl. Comp., 45 (2009) 1413–1415].
5. V. Gefenas, Ţ. Stankevičiūtė, A. Malinauskas, Khim. Geterotsikl. Soedin., (2010) 464–467. [Chem.
Heterocycl. Comp., 46 (2010) 372–374].
105
SYNTHESIS, STRUCTURAL AND CIRCULAR DICHROISM STUDY OF SOME
EXOCYCLIC BENZYLIDENE SUBSTITUTED BICYCLONONANES
S. Stončius, A. Neniškis
Department of Organic Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius,
Lithuania
E-mail: [email protected]
Bridged bicyclic and polycyclic compounds are suitable model structures for studying
chiroptical properties and transannular interactions between non-conjugated chromophores
due to an appropriate molecular geometry and well-defined spatial orientation of functional
groups. Herein we present the synthesis, structural and chiroptical studies of exocyclic
benzylidene substituted enone 1 and related structures 2-5.
150
4
100
1
50
0
-50
2
3
-100
200
250
300
350
, nm
Molecular modeling and X-ray structure of enone 1 proved substantial twisting of the enone
chromophore. In the CD spectrum of 1, a very intensive bisignate exciton couplet centered at
ca 300 nm is observed. The latter originates from transannular interaction and exciton
coupling between the two non-conjugated enone chromophores. Analogously, the strong
negative couplets observed in the CD spectra of unsaturated exocyclic derivatives 2-4 are due
to exciton coupling between the two π π* transitions of the styrene chromophores. The
negative twist defined by interacting transition moments in the structures 1-4 is in agreement
with the negative couplets observed in the CD spectra. The intensities of the Cotton effects
correlate with the interchromophoric distance, which depends on the substitution pattern.
Synthetic transformations of enone 1, including the cyclization to tricyclic brexane derivative
5, and the molecular geometries of compounds 1-5 will be discussed.
Acknowledgements: This work was funded by the Research Council of Lithuania (Global
Grant Programme No. VP1-3.1-ŠMM-07-K-01-030).
106
ON ACID DECOMPOSITION OF SELENO – AND TELLUROPENTATHIONATES
Judita Sukyte
University of Technology, Radvilenu pl. 19, LT-50254, Kaunas, Lithuania
E-mail:[email protected]
Monoselenopentathionic H2SeS4O6 and monotelluropentathionic H2TeS4O6 acids were
isolated from its barium salts, BaSeS4O6 2H2O and BaTeS4O6 3H2O, in the reaction of
precipitation of BaSO4 with the solution of H2SO4 [1-3]. In neutral or slightly acid solutions
chalcopentathionates decomposes into chalcogen and tetrathionate [4]:
SeS4O62- Se + S4O62TeS4O62- Te + S4O62In the synthesis of H2SeS4O6 with aim to isolate more concentrated solutions we tried to treat
powdered crystalline BaSeS4O6 2H2O with conc. H2SO4 ( = 1.832 – 1.841 g/cm3, 94.32 % or
17.608 mol/dm3). Unexpectedly, we found that in the reaction with conc. sulphuric acid
BaSeS4O6 rapidly decomposes into orange – yellow precipitates (el. Se and S) with the
releases of H2Se, H2S, and SO2, and some amounts of H2SO4. Experimental data could not be
presented by classical and simple reaction mechanism. We sugest the acid decomposition of
selenopentathionate follows a 2-step mechanism involving the formation of a kinetically
significant intermediates., e.g., sulfane-monosulfonates H-Sn-SO3H [6, 7] or their analogous,
new compounds selenane-monosulfonates [1]:
HO H
HO3S  S-Se-SO3H H2SO4 + HSSeSSO3
This compound might be decomposed in two ways:
1. with elimination of S and Se: HSSeSSO3 Se + 2S + H2SO3
2. with elimination of H2S and formation of new selenopolythionic acid:
2HSSeSSO3 H2S + H2Se2S5O6
The catalytic action of hydrogen ion on the stability of seleno- and telluropentahionate could
be interpreted on the basis of the properties of their central sulfur and chalcogen atoms [4]. At
sufficiently high acid concentrations the polarizing proton effect causes breakdown of the
chalcopentathionic acid with liberation of hydrogen selenide or telluride and elemental
selenium or tellurium in the case of chalcopentathionates, respectively [5]. The decomposition
of chalcopolythionic acids follows the first-order reaction law [3]. The direct dependence of
an apparent reaction rate constant from the acide‟ concentration exists for all isolated acids:
kapparent = 2.70 10-5 [H2SeS4O6] + 3.00·10-6, s-1, 50°C
Probably, the hydrogen ions of chalcopolythionic acid provide catalytic action to the
decomposition of their anions. In the case of selenopentathionic acid this relation is valid in
the range of concentration of 0.4 – 3.0 mol/dm3. With further increase of concentration the
rate of decomposition increases sharply and the decomposition goes according the reactions
described above with release of hydrogen chalcogenides and formation of new compounds
containing sulfur or chalcogen chains terminated by sulfonate groups [4, 6-7].
References
1. J. Šukytė, Doctoral thesis, Kaunas, 1973.
2. J. Šukytė, R. Ivanauskas, V. Janickis, Int. Conf. “Chemistry and Technology of Inorganic Compounds”,
April 21, Kaunas, Lithuania, 2004, 57 58.
3. V.I. Zelionkaitė, V.J. Šukytė, J. Inorg. Chem. 18/9, (1973) 23474. O. Foss, In Advances in inorganic chemistry and radiochemistry; Ed. H.J. Emeleus, A.G. Sharpe,
Academic Press, New York, 1960, 2, p. 243 – 278.
5. V.J. Šukytė, R. Ivanauskas and V. Janickis., Polish J. Chem., 79 (2005) 759-771.
6. M. Schmidt, Z. anorg.u.allgem.Chem., 289 (1957) 158.
7. F. Feher, J. Schotten, B. Thomas, Z. Naturforsch., 13 b (1958) 624.
107
ELECTRODEPOSITION OF CrNi ALLOYS FROM AQUEOUS OXALATE BATH
S. Survilienė, A. Češūnienė, A. Selskis, R. Butkienė, I. Jurevičūtė
Centre for Physical Science and Technology, A.Gostauto 9, 01108 Vilnius, Lithuania
e-mail: [email protected]
The electrodeposition and properties of CrNi alloy coatings were studied using trivalent
chromium plating baths containing NiSO4 and oxalate as a complexing agent. Till now
simultaneous electroreduction of both nickel and chromium ions and formation of CrNi alloys
from Cr(III)+Ni(II) solutions were discussed without regard for solution chemistry. As
deposition of Cr or its alloy from Cr(III) baths is difficult owing to both thermodynamic and
kinetic considerations, the effect of Cr(III)+Ni(II) solution chemistry should be taking into
account. The purpose of this investigation was to consider in detail the electrochemical and
chemical processes that occur during deposition of CrNi alloys.
It has been found that the formation of CrNi alloy begins at a less negative potential (-0.9 V)
than that of pure Cr (-1.3 V) in the absence of Ni2+ ions, which suggests that Cr nucleates on
Ni giving CrNi, alloy. The underpotential deposition of Cr may be explained by adsorption of
chromium on electropositive (relative to chromium) as-deposited nickel layer with subsequent
alloy formation [1], the physical meaning of which was quantitatively explained in [2]. Even
greater shift to less negative potentials was observed during electrodeposition of CrNi alloy
on polymer-modified surfaces. It was found experimentally, that a thick (about 40 μm) Crrich coating with a uniform bright surface and good adherence to the substrate might be
deposited from the oxalate bath. As the duration of electroplating increased (>30 min), the
deposits gradually turned from shiny metallic to dull metallic and dark gray. This might be
associated with the formation of solid chromium hydroxide particles since pH of the near
cathode layer increased during electrolysis.
To obtain some information concerning nucleation and growth of the deposits on the cathodic
surface, current-time curves (CTCs) were recorded at various potentials. The morphology of
CrNi alloy has showed nanoscale particles with a large number of pores. The deposit surface
has become coarse and the percentage of Ni in the alloy has increased from 6 to 50 at% when
the temperature of electrolysis has increased from 30 to 40 oC.
To identify the Cr(III) species in the electrolyte the visible absorption spectra (VS) of Cr (III)
complexes were recorded. As the inorganic species in Cr(III) complexes may be replaced by
the organic ligands (L) forming various organo-chromium complexes [3], the number of
organic ligands in the Cr(III) complexes affects the UV-visible spectrum. It is shown that
NiSO4 added to the Cr(III)-oxalate solution has no effect on the absorption maxima positions
of Cr (III) complex. A decrease in the absorption peaks recorded for the spent solutions was
more significant in the presence of Ni2+ ions, which suggested the formation of binuclear
[(H2O)nCr(C2O4)Ni(H2O)n] and [(H2O)nCr(C2O4)(OH)Ni(H2O)n] complexes in which metal
atoms are linked together via an oxalate ligand and/or a hydroxo- bridge [4]. The formation of
such structures may be the cause of a decrease in concentration of the active Cr(III) complex.
Attempts to reveal any distinctions between FT-IR spectra recorded before and after addition
of NiSO4 in the Cr(III)-oxalate solution have not been successful. This suggests that the
structures of oxalic complexes are similar in both cases.
References
1. A.A. Edigaryan, E. H. Lubnin, Y.M. Polukarov, Zashch. Met., 36 (2000) 565-569..
2. D.M. Kolb, M. Przasnycki and H. Gerischer, J. Electroanal. Chem. 54 (1974) 25-38
3. Y.B. Song and D.-T. Chin, Electrochimica Acta 48(4) (2002) 349-356.
4. K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds, New York, John
Wiley and Sons, 1986
108
DIELECTRIC PROPERTIES OF 0.4Na1/2Bi1/2TiO3 – (0.6 – x)SrTiO3 - xPbTiO3 SOLID
SOLUTIONS
Š. Svirskas1, M. Ivanov1, Š. Bagdzevičius1, J. Banys1, M. Dunce2, M. Antonova2, E.
Birks2, A. Sternberg2, V.Zauls2
1
Vilnius University, Faculty of Physics, Saulėtekio av. 9, III b., LT-10222 Vilnius, Lithuania
2
Institute of Solid State Physics, University of Latvia, Kengaraga street 8, LV-1063 Riga,
Latvia
e-mail: [email protected]
Many solid solutions based on Na1/2Bi1/2TiO3 (NBT) were brought to the daylight of
ferroelectric society in order to find low-lead compositions suitable for practical applications.
Barium titanate (BT), strontium titanate (ST) and lead titanate (PT) were used as secondary
materials for NBT solid solutions [1, 3]. The only report on such solid solutions as NBT-STPT is published in [2]. It is known that PT and ST influence phase transition of NBT
differently. PT induces ferroelectric phase transition, while ST enhances relaxor properties
[1]. So the main interest is to
400 K
350 K
320 K
250 K
8000
find out how these materials
6000
'
interact with each other in
NBT solid solutions.
Fig.
frequency
1
4000
2000
shows
dependence
0
1500
of
1200
dielectric
permittivity for x = 0.1. The
purpose of the report is to
investigate
dielectric
dynamic
properties
900
''
complex
600
300
0
0
10
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10
Frequency [Hz]
of
Fig. 1 Frequency dependence of complex dielectric permittivity for
0.4NBT-(0.6-x)ST-xPT for x = x = 0.1 at different temperatures, solid lines are fits with Havriliak0.1 and 0.15.
Negami formula
References
[1] Lee, J.K.; Hong, K.S.; Kim, Ch.K.; Park, S.E.; Phase transitions and dielectric properties in A-site ion
substituted (Na1/2Bi1/2)TiO3 ceramics (A=Pb and Sr), Journal of Applied Physics, vol. 91, No.7 (2002)
[2] Birks, E., Dunce, M., Antonova, M. and Sternberg, A., Phase transitions in modified Na 1/2Bi1/2TiO3-SrTiO3
solid solutions, Physica Status Solidi C, vol.6, No.12 (2009)
[3] Gomah-Pettry, J.R.; Said, S.; Marchet, P.; Mercurio, J.P.; Sodium-bismuth titanate based lead-free
ferroelectric materials, Journal of the European Ceramic Society, vol. 24, Issue 6, Electroceramics VIII (2004)
109
ELECTROCHEMICAL AND ENZYMATIC REDUCTION OF
BENZOFUROXAN DERIVATIVES
A. Šaikūnas, J. Šarlauskas*, Ţ. Anusevičius, L. Misevičienė, K. Krikštopaitis,
A. Marozienė, V. Miliukienė and N. Čėnas
Vilnius University, Institute of Biochemistry, Mokslininkų 12, Vilnius, 08662, Lithuania *E-mail:
[email protected]
Benzofuroxan derivatives are remarked group of the so-called „quinoidal“ heterocycles,
containing in their structure a strong electron-accepting furoxan fragment, equivalent of the two
„masked“ neighboring NO2 groups.
The pharmacological action and biodegradation of these compounds are frequently related to
their flavoenzyme-catalyzed 1e-/2e-(4e-) reduction [1, 2]. In order to understand their
bioreduction mechanisms and enzyme substrate specificity, and to predict the pathways of their
biodegradation, one has to characterize their electron-accepting properties. In this work, we
performed cyclic voltammetry studies (pH 7.0, aqueous medium) of a number of benzofuroxans.
Their reduction peak potentials (Epc) were found to range from -731 to - 314 mV vs.Ag/AgCl
being dependent on the electron-accepting properties of the ring substituents. The preliminary
study of enzymatic reactivity of benzofuroxans was carried out using Glu301 Ala-ferredoxin:
NADP+ reductase (E301A-FNR) as a model flavoenzyme.
Table 1. Epc and bimolecular rate constants (kcat/KM ) of conpounds reduction by E301A-FNR
No.
Compound
1.
2.
3.
4.
5.
6.
Benzofuroxan
4-Nitrobenzofuroxan
5-Nitrobenzofuroxan
4,6-Dinitrobenzofuroxksan
4,6-Dimetilbenzofuroxan
4,6-Diamino-5,7dinitrobenzofuroxan
4-Amino-5,7dinitrobenzofuroxan
7.
Epc mV (Ag/AgCl,
50 mV/s)
-500
-480, -624
-492, -637
-513, -665
-731
-314, -761, -834
E301A-FNR kcat/KM
(M-1s-1)
(5,1±1,5)×103
(7,5±0,7)×105
(2,0±0,1)×105
(1,8±0,3)×105
(1,7±0,4)×106
-460, -640, -820
(2,0±0,4)x106
Typically, the reduction peak current was proportional to the square root of the
potential scan rate, which is consistent with the diffusion-controlled electrochemical process.
This research was funded by a grant No. MIP-11248 “Heterocyclic N-Oxides (HNO):
synthesis, cytotoxicity and interaction with enzyme-targets” from the Research Council of
Lithuania.
References:
1. D.J. Abraham (Ed.) Cardiovascular Agents and Endocrines, In: Burger‟s Medicinal Chemistry and Drug Discovery, WileyInterscience, N.Y., Vol. 3 (2003), 11.
2. N. Čėnas, A. Nemeikatė-Čėnienė, J. Šarlauskas, Ţ. Anusevičius, L. Misevičienė. Mechanisms of Mammalian Cell Cytotoxicity
of Explosives. In: Ecotoxicology of Explosives, CRC Press, Boca Raton-London-N.Y., 2009, 211.
110
SYNTHESIS OF Hsp90 CHAPERONE INHIBITORS
D.Tauraitėa, M. Morkūnasa, M. E. Maierb
a
Institute of Biochemistry, Vilnius University, Mokslininkų 12,
LT-08662 Vilnius, Lithuania
b
Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076
Tübingen, Germany
E-mail: [email protected]
Heat shock protein (Hsp90) is ATP-depended chaperone protein essential for the
maturation and activity of a varied group of proteins involved in signal transduction, cell
cycle regulation, and apoptosis [1]. The ATPase activity of Hsp90 can be inhibited by natural
products antibiotics such as geldanamycin and radicicol [2]. Despite the fact that a large
number of different Hsp90 inhibitors have been synthesized [3], only few of them are
clinically tested. There still remains a great need of new potential Hsp90 inhibitors which
offer one or more following advantages: improved activity and selectivity, solubility, reduced
toxicity and side-effects and reduced cost of synthesis. Herein high-yielding synthesis of
substituted 1,2,3-thiadiazoles and three new molecules, that are shown below, will be
discussed. It was predicted, that this kind of aromatic frame could be very promising [4], and
bicyclic part was chosen as another necessary one.
O
HO
R
O
X
Ar
HO
HO
N
S
N
OH
X = CH2, O, NH
All synthesized compounds will be measured as Hsp90inhibitors to check the activity.
These measurements will be done in the Institute of Biotechnology, Vilnius University using
isothermal titration calorimetry (ITC) method.
References
1.
2.
3.
4.
J.C. Young., I. Moarefi, F.U.J. Hartl, Cell Biol., 154 (2001) 267-273.
S. Soga, Y. Shiotsu, S. Akinag, S.V. Sharma, Curr. Cancer Drug Targets, 3 (2003) 359-369.
B.W. Dymock, X. Barril, P.A. Brough, J.E. Cansfiueld, A. Massey, E. McDonald, R.E. Hubbard, A.
Surgenor, S.D. Roughley, P. Webb, P. Workman, L. Wright, M.J.J. Drysdale, Med. Chem., 48 (2005)
4212-4215.
H.S. Christensen, S.V. Boye, J. Thinggaard, S. Sinning, O. Wiborg, B. Schiųtta, M. Bols, Bioorg. Med.
Chem., 15 (2007) 5262–5274.
111
CHARACTERIZATION AND SUGGESTED USAGE IN FOOD INDUSTRY OF
NATURALLY DERIVED CALCIUM COMPOUNDS
J. Trinkunaite-Felsen, A. Zalga, A. Kareiva
Department of General and Inorganic Chemistry, Faculty of Chemistry, Vilnius University,
Naugarduko str. 24, LT-03225 Vilnius, Lithuania
E-mail: [email protected]
Health benefits of calcium compounds are widely acknowledged [1-6], health claims linking
calcium and bone health in postmenopausal women were issued in Europe by The European
Food Safety Authority (EFSA). An adequate intake of both calcium and vitamin D is
important for bone health and is recognized as an important component of any osteoporosis
prescription-drug regimen. Indeed, as part of the US Food and Drug Administration‟ s
approved labelling of all bisphosphonates used for the prevention and treatment of
postmenopausal osteoporosis, correction of disorders of mineral metabolism such as calcium
and/or vitamin D deficiency is mandatory before initiating therapy. The risk of one or another
health condition arises when people do not consume the Recommended Daily Intake (RDI) of
calcium through their daily diet. Recent studies revealed that calcium intake is inadequate in
both children and elderly people [7-9].
Calcium supplements and calcium-fortified foods are additional sources of calcium for people
unable to consume sufficient dietary calcium [10, 11]. Calcium supplements are available in a
variety of different calcium salts. The specific salt tends to determine application form,
concentration of elemental calcium in it as well as it can affect the circumstances surrounding
administration and bioavailability.
In this work naturally derived calcium containing compounds from dairy, corals, sea-shells,
bones and/ or others are analysed and characterized using infrared (IR) spectroscopy, X-ray
diffraction (XRD) analysis and scanning electron microscopy (SEM). These methods are
indispensable tools in order to learn some special features of calcium compounds, identifying
their composition, structure as well as describing particle size and surface morphology. From
the obtained results functional properties, usage in food industry and theoretical
bioavailability of the corresponding compounds are evaluated.
References:
[1] Rao L. G. , Khan T., Gluck G., Biosci Biotechnol Biochem., 71, 336-42 (2007).
[2] Muehrcke D.D.,Shimp W.M., Aponte-Lopez.R., Ann Thorac Surg.,88, 1658-61 (2009).
[3] Bonjour J. P., Carrie A. L., Ferrari S., Clavien H., Slosman D., Theintz G., Rizzoli R., J Clin Invest., 99,
1287-94 (1997).
[4] Sharma S. V., Hoelscher D. M., Kelder S. H., Diamond P., Day R. S., Hergenroeder A., J Am Diet Assoc.,
110, 932-6 (2010).
[5] Chan G. M.,McElligott K., McNaught T., Gill G., Obstet Gynecol., 108, 565-71 (2006).
[6] Lau E. M.,Woo J., Leung P. C., Swaminathan R., Leung D., Osteoporos Int., 2, 168-73 (1992).
[7] Xingqiong M., Deborah A. K., Kun Z., Amanda D., Vicky S., Colin W. B., Richard L. P., Nutrients , 2,
1036-1043 (2010)
[8] Lee Y. H., Lim Y. W., Ling P. S., Tan Y. Y., Cheong M., Lam K. S., Singapore Med J., 48, 1117-21 (2007).
[9] Vargas-Zárate M, Becerra-Bulla F, Prieto-Suárez E., Rev Salud Publica (Bogota)., 12, 116-25 (2010)
[10] Ervin R. B., Wang C. Y., Wright J. D., Kennedy-Stephenson J., Adv Data., 341, 1-5 (2004).
[11] Plawecki K. L., Evans E. M., Mojtahedi M. C., McAuley E., Chapman-Novakofski K., Prev Chronic Dis.,
6, A124 (2009)
112
REACTION PRODUCTS OF 3-[(4-METHYLPHENYL)AMINO]
PROPANOHYDRAZIDE WITH ARYL ISOCYANATES AND THEIR
TRANSFORMATIONS
I. Tumosienė, K. Kantminienė, Z. J. Beresnevičius
Kaunas University of Technology, Lithuania, Radvilėnu pl. 19, 50254 Kaunas
E-mail: [email protected]
We have reported the cyclization of N-phenyl- -alanine hydrazide [1], and semi- and
semithiocarbazides of N-carboxyphenyl-N-phenyl- -alanine [2] to compounds containing one
or several azole fragments.
In this work, cyclization reactions of N-(4-methylphenyl)- -alanine hydrazide and its N‟phenylcarbamoyl derivatives to oxa-, thiazole, thiadiazole, and triazole derivatives were
carried out.
Ar
H
N
RC6H4 NCX
Ar
H
N
POCl3
1
X
N
H
O
NH2
O
S
N
RC6H4 NCX
N
H
N
R
N
H
2- 4
2 RC6H4 NCX
H
N
R
H
N
H
N
Ar
5-7
a) KOH
b) NH2NH2
R
R
X
X
POCl3
Ar
Ar
N
N
H
N
H
N
R
X
N
N
8 - 10
KOH
O
N
H
Ar = 4-CH3C6H4
H
N
Ar
N
X
N
H
N
N
H
11 - 13
R
NH
R
14 - 16
X
X 11,
= O,14 R = H, X = O;
2, 5, 8,
X 12,
= S,15 R = H, X = S;
3, 6, 9,
4, 7, 10, 13, 16 R = CH3, X = S.
References
1.
2.
I. Tumosienė, Z. J. Beresnevičius. Synthesis of azoles from 3,3′-[(4-alkoxyphenyl)imino]bis(propanoic acid
hydrazides). Monatshefte fur Chemie. 2009, Vol. 140, iss. 12, p. 1523-1528.
I. Tumosienė, K. Kantminienė, A. Pavilonis, Ţ. Maţelienė, Z. J. Beresnevičius. Synthesis of azole
derivatives from 3-phenylaminopropanohydrazide and evaluation of their antimicrobial efficacy.
Heterocycles. 2009, Vol. 78, no. 1, p. 59-70.
113
INVESTIGATION OF FUNGISTATIC PROPERTIES OF PAPERS TREATED WITH
BROMOSEPT 50 OR P-3 TRIQUART COMPOUNDS
M. Urbaitytė1,2, A. Beganskienė1, I. Bubinienė3, J. Lukšėnienė3
1
Vilnius University, Faculty of Chemistry, Naugarduko 24, Vilnius, Lithuania
2
Vilnius University, Library Restoration Centre, Universiteto 3, Vilnius, Lithuania
3
Lithuanian Art Museum P.Gudynas Centre for Restoration, Rūdininkų 8, Vilnius, Lithuania
Libraries and museums are responsible for preserving heritage; they have the challenge to
preserve millions of books printed on fragile paper. But, libraries and archives sometimes have
suitable conditions for fungal growth, which is highly dependent of temperature and humidity. The
high humidity and temperature are frequent, have environmental conditions that encourage the
development of these microorganisms. This situation can bring risks for books and documents.
Fungi can hydrolyse a wide variety of polymers, including cellulose, as a result of their efficient
degradative enzymes. Cellulolytic fungi, which use cellulose as substratum, when growing in
favorable environmental conditions, can destroy paper material in a short time
The fungal activity is generally associated with an increased activity of the enzyme cellulase
activity, which leads to destruction of the fibers [1, 2]. Microbiological pollution and its effects are
extremely dangerous, even disastrous, and for the performance of works of art on paper: microstorey paper, toner and ink binders, leaving undesirable color spots. One of the most effective
means to inhibit microbiological contamination is a biocide. The main requirement for materials
used in the protection of cultural values and hence the biocides is their compatibility with the
preservation or restoration of course materials.
The aims of this study is the determination the impact of fungicide materials Bromosept 50
and P3 - Triquart (quaternary ammonium salts) for paper, also, the minimum concentrations of
fungicidal materials and acidity change during the thermal aging time.
References
1. Minderienė R., Krikštaponis A., Fungicidinio poveikio medţiagų pritaikymo popieriaus konservavime tyrimai, LDM
metraštis, T. VI, 2005.
2. Lugauskas A., Bridţiuvienė D., Levinskaitė L., Paškevičius A., Pečiulytė D., Repečkienė J., Salina O., Varnaitė R.,
Mikrobiologiniai medţiagų paţeidimai. Vilnius: Valstiečių laikraštis., 1997.
114
SYNTHESIS OF 4,7-DIARYL-2-METHYLTHIO-7H-PYRROLO[2,3-d]PYRIMIDINES
BY THE SUZUKI COUPLING AND N-ARYLATION REACTIONS
R. V. Urbonas, V. Poskus, J. Dodonova, S. Tumkevicius
Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania
[email protected]
Organic molecules with -conjugated backbone have attracted a growing interest over
recent years owing to their applications in a wide range of electronic and optoelectronic
devices [1]. Recently, pyrrolo[2,3-d]pyrimidine-core based oligoarylenes with aryl branches
have been elucidated as blue light-emitters due to their strong fluorescence [2]. To develop
more efficient fluorescent materials we report herein on the synthesis of novel pyrrolo[2,3d]pyrimidines with various aryl branches at positions 4 and 7 of the heterocyclic moiety.
Scheme 1
i
iii
N
MeS
N
Cl
Cl
N
N
4
O
MeS
Bu-t
MeS
N
O
N
1
N
H
N
MeS
N
N
3 (23%)
R
R
R
iv
ii
N
N
N
N
N
H
Cl
ii
i
MeS
N
2 (traces)
N
5 O
Bu-t
O
MeS
N
H
N
6
R = H, 4-OMe, 4-Ph, 4-CHO
R' = H, R' = NPh2; R' = CN
MeS
N
N
7
R'
Reagents and conditions: i) ArB(OH)2, Pd(OAc)2, PCy2(2-biPh), K3PO4, dioxane, Ar; ii) ArI(Br), CuI, (±)-trans1,2-diaminocyclohexane, K3PO4, dioxane, Ar; iii) Boc2O, DMAP, DIPEA, DCM, r.t.; iv) TFA, DCM
Synthetic routes to the title compounds have been explored. The shortest route to
compounds 7 using the Suzuki coupling or N-arylation reactions of 1 did not give the
desirable results (Scheme 1). Therefore, for the preparation of 4,7-diarylpyrrolo[2,3d]pyrimidines a synthetic method consisting of four reactions sequence - protection of N(7)-H
group in 1, cross-coupling reaction of the obtained 4 to give 5, deprotection of 5 and Narylation reactions of 6 with halobenzenes - has been developed. It is worth to mention, that
the Suzuki coupling of 4 with arylboronic acids bearing electron-donating groups proceeded
smoothly and furnished pyrrolopyrimidines 5 in good yields (64-86%). However, reactions of
compound 4 with p-R-phenylboronic acids containing electron-withdrawing groups (R=CHO,
NO2) or with potassium (p-trifluoromethylphenyl)trifluoroborate did not give the desirable
result. Only reaction of 4 with p-formylphenylboronic acid furnished the corresponding 5
(R=CHO) in 28% yield, while in other two cases complex inseparable mixtures were
obtained. N-Arylation of 6 with selected haloarenes using CuI/(±)-trans-1,2diaminocyclohexane/K3PO4 as a catalyst system afforded 7 in 68-99% yields.
1.
2.
(a) G. Hughes, , M. R. Bryce, J. Mater. Chem., 15 (2005) 94-107; (b) W.Y. Wong, G.-J. Zhou, X.-M.
Yu, H.-S. Kwok, Z. Lin, Adv. Funct. Mater., 17 (2007) 315-323.
S. Tumkevicius, J. Dodonova, K. Kazlauskas, V. Masevicius, L. Skardziute, S. Jursenas, Tetrahedron
Lett., 51 (2010) 3902-3906.
115
PROCESSABLE AMBIPOLAR FULLERENE[60]-ARYLHYDRAZONE DYADS
S. Urnikaite,1 T. Malinauskas,1 V. Gaidelis,2 V. Jankauskas,2 V. Getautis 1
1
Department of Chemical Technology, Kaunas University of Technology, Radvilenu pl. 19,
LT-50254 Kaunas, Lithuania
2
Department of Solid State Electronics, Vilnius University, Sauletekio 9, LT-10222 Vilnius,
Lithuania
E-mail: [email protected]
Compared to the extensive literature on the hole and electrone transporting molecules,
compounds capable of transporting both electrons and holes were studied a lot less intensively
[1]. The ambipolar charge transport in the amorphous organic semiconductors have been
established basically in the molecular composites combined of a set of hole and electron transport
materials.
In this work fullerene[60]-arylhydrazone dyads FH1 and FH2 have been synthesized utilizing
Prato-Maggini-Scorrano reaction followed by the condensation with phenylhydrazines [2]:
CH3
H3C
N
H2N
R
R
O
N
OH
C60,
H3C
H
N
toluene, reflux
O
H3C
N
N
N
H3C
CH3
N
FH1
N
N
N
O
2a,b
1a,b
H2N
O
N
N
H3C
N
N
N
1a, 2a R = CHO
1b, 2b R = H
N
FH2
A new guest-host system composed of dyads FH1 and FH2 as charge transporters and amorphous
2,2-bis{4-[2-hydroxy-6-(carbazol-9-yl)-5-(carbazol-9-methyl)-4oxahexyloxy]phenyl}propane (CBH) as host for ambipolar charge transport application was developed and
investigated. Charge transport properties were studied by xerographic time of flight (XTOF)
technique. Electron and hole mobilities in the composition of FH1 and CBH (1:1) are 7 10-6 and
1.5 10-6 cm2V-1s-1 (at at an electric field of 3.6·105 Vcm-1) accordingly. Drift mobilities of the
composition of FH2 and CBH are 1.6 10-6 cm2V-1s-1 for electron and 1.15 10-5 cm2V-1s-1 for holes
(at an electric field of 3.6·105 Vcm-1). Additionally, the guest-host composition of FH1, FH2 and
CBH (1:1:2) was prepared. In this case electron and hole mobilities are balanced: 2.2 10-6 and
3.4 10-6 cm2V-1s-1 accordingly.
References
1. Zaumseil J., Sirringhaus H. Chem. Rev., 107 (2007) 296-323.
2. Urnikaite S., Malinauskas T., Gaidelis V., Maldzius R., Jankauskas V., Getautis V., Carbon 49 (2011) 320-325.
116
MONITORING OF PESTICIDE RESIDUES IN 2009
V.Vaičiūnas, R. Golubevas, J.Petraitis, I.Jarmalaitė,
National Food and Veterinary Risk Assessment Institute (NFVRAI), LT-08409, Vilnius, Lithuania
E-mail: [email protected]; [email protected]
Every year food of plant origin is checked for pesticide residues in accordance with the
EU and national monitoring programme [1]. Samples were mainly analysed by multi-residue
method EN 12393-(1-3):2000. The samples were extracted with or acetone,
cyclohexane/ethyl acetate, cleaned up on gel permeation column, and determined by capillary
gas chromatography and extraction with methanol cleaned up on diatomaceous earth and
analysis by gas and liquid chromatography with GC/MS and LC-MS/MS. The QuEChers
extraction method was implemented. EN 15637:ChemElut. Dithiocarbamates were
determines by method EN 12396-1:2000. Pesticides surveyed: - Maneb group and Thiuram.
The Quality Assurance procedures described in SANCO document [2] were used.
310 samples of fruit, vegetables, cereal, processed and baby food were analysed for
pesticide residues in 2009. 81 samples (26 %) were of domestic origin, 127 samples (41 %)
were from other EU countries, 102 (33 %) samples were imports from third countries.
Fruit and vegetables: Total number of samples tested was 251, Fruits and nuts – 138,
infusions – 4, Oil plants -4, vegetables -105. 36 Samples (14.4 %) were of domestic origin,
118 samples (47.0 %) were from other EU countries, 97 - (38.6 %) samples were from third
countries. Samples were analysed for up to 274 residues (pesticides and metabolites).
Pesticide residues were not detected in 121 samples (48.2 %), 119 samples (47.4 %)
contained residues in level below or at the level of Maximum Residue Limits (MRL); in 11
samples (4.4 %) the EU MRLs were exceeded.
Cereals: Total number of samples tested was 21. Of the samples taken, 17 samples (81
%) were of domestic origin, 4 samples (19 %) were imports from third countries. Samples
were analysed for up to 250 residues. Pesticide residues were not detected in 17 samples (81
%), 3 samples (14.2 %) contained residues in level below MRL; in 1 sample (4.8 %) the EU
MRL was exceeded.
Animal products. Total number of samples tested was 28. All samples domestic origin.
Samples were analysed for 48 pesticide residues. Pesticide residues were not detected in 26
samples, above MRL were determined in 2 samples (7.1 %).
Baby food: 10 samples of baby food were tested for pesticide residue. 9 samples (90 %)
were from EU countries and 1 (10 %). All samples were free from pesticide residues.
The most commonly detected pesticides were azinphos-methyl, azoxystrobin, boscalid,
carbendazim, chlorpyrifos, chlorpyrifos-methyl, chlorothalonil, cyprodinil, cypermethrin,
diazinon, dimethoate, dithiocarbamates, endosulfan, ethion, fenhexamid, fenitrothion,
fenpropathrin, fludioxonil, flutriafol, hexythiazox, imazalil, imidoxacarb, imidachlorprid,
iprodione, malathion, methiocarb methidathion, myclobutanil, penconazole, phosmet,
procymidone, propargite, pyrimphos-methyl, quinoxyfen, thiophanate-methyl, tolylfluanid,
triadimefon, tribendazole, trifloxystrobin.
References
1. Commission regulation (EC) No 1213/2008
2. Method validation and Quality control procedures for pesticide residues analysis in food and feed. Document
No. SANCO/3131/2007.
117
Treatment of water-based paint wastewater with Fenton process
T.Vengris, R.Binkienė, R.Butkienė, R.Ragauskas, A.Stončius
Center of physical sciences and technology, Institute of Chemistry
Goštauto 9, Vilnius, Lithuania, e-mail:[email protected]
Painting industry wastewaters, contaminated by organic and inorganic pigments, binders,
thickeners and other additives create serious ecological problems. In many cases these
wastewaters, especially that including UV dyestuff are not biodegradable, so the other
treatment methods must be implemented. In this work the treatability of water-based paint
wastewater by Fenton process had been studied. Fenton process is based on the oxidizing
pover of OH˙ radicals and is thoroughly described in monographs [1,2].
The object of investigation was water-based paint wastewater (WPW) from Lithuanian
enterprise „Universal wood products“, located in Ukmergė city. This water results from
cleaning of the equipment used in coating productions. After primary treatment by CaCl2,
FeCl3, Ca(OH)2 and sedimentation, the chemical oxygen demand (COD) of residual
wastewater amounts 16000-18000 mgO2/l. According to the paint production technology the
main paint components, as well as that of wastewater are water-soluble organic compounds:
1-butoxy-2-propanol (BP), dipropylene glycol monomethyl ether (mixture of isomers) (DGE), 2hydroxy-2-methylpropiophenone (HMP), 2-butoxyethanol (BE) and acrylates oligomers
(AO), all of them are nominated as harmful.
Fenton oxidation was performed in chemical beaker, adding to 100ml wastewater appropriate
amount of hydrogen peroxide and ferric sulfate salt. COD of tested solutions was established
by the standard potassium dichromate oxidation method, using a Spectroquant TR 320 reactor
and a Spectroquant Picco Colorimeter. Organic compounds were analyzed by GC/MS
(Shimadzu, Japan) and GC/FID (Clarus 500, USA).
The influence of temperature, pH, concentrations of H2O2 and FeSO4 on the effectiveness of
COD reduction have been established. Approximately even results of COD reduction in pH
range 2,5-5,5 were achieved. 1M H2O2 and 0,1-0,01M Fe(II) concentrations acted most
effectively. In 20 - 50o C temperature range roughly even COD reduction was reached, yet
with different reaction kinetics. At optimal reaction conditions established, around 80% COD
reduction has been achieved. It coincide with the results of other authors [3] in similar
investigation. COD reduction kinetics at different Fenton reagent concentration is shown in
Table.
Table. COD(mgO2/l) change kinetics in WPW at pH=2.5 and 50oC temperature at different Fenton components
concentrations. Initial COD=16500 (mgO2/l)
Fenton components 0.5 h
1h
2h
3h
24 h
concentrations.
0.5M H2O2, 0.01M
Fe(II)
1M H2O2, 0.01M
Fe(II)
7000
6750
4500
4350
4550
6500
4500
3550
3500
3500
The effective Fenton reaction run is about 2h. The increase of hydrogen peroxide
concentration enhances the COD reduction, but out of proportion to peroxide concentration.
GC/MS analysis showed no BP, DGE, HMP, BE and AO compounds in WPW after Fentons
treatment.
1. Neyens, E., Baeyens, J. Hazard Mat., B98 (2003) 33-50.
2. Pignatello, J.J., Oliveros, E., MacKay, A., Crit. Rev. in Envir Sci and Techn., 36 (2006) 1-84.
3. Kurt, U., Avsar Y., Gonullu M.T. Chemosphere., 64 ( 2006) 1536-1540.
118
SYNTHESIS OF WATER SOLUBLE CATIONIC MOLECULAR BRUSHES
C. Visnevskij, A. Baceviciute, R. Makuska
Department of Polymer Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius,
Lithuania
E-mail:[email protected], [email protected]
Molecular brushes are extraordinary polymeric molecules whose conformation can be
varied by changing in temperature, pH, ionic strength and solvent quality. Controlled radical
polymerization is superior among several methods of the synthesis of molecular brushes,
because of good control of molecular structure and polydispersity [1]. Atom transfer radical
polymerization (ATRP) is one of the most perspective and successful controlled/living radical
polymerization (CRP) techniques. Polymers synthesized via ATRP have low polydispersity
and various architectures such as block, gradient, brush, multiarmed, end-functional, etc. [2].
In the present work, we aimed to synthesize molecular brushes with cationic tail
through which they could adsorb effectively to negatively charged surfaces (Fig. 1) and
modify surface properties. Cationic tail was composed of [2-(methacryloyloxy)ethyl]
trimethylammonium chloride (METAC) units, and the brush segment was build from
poly(ethylene oxide) methyl ether methacrylate (PEO45MEMA, Mn = 2080) units.
Figure 1. Sorption model of molecular brush containing cationic tail to negatively charged surface
Using one approach, PEO45MEMA homopolymer was synthesized first with the aim
to use it as a macroinitiator for AGET ATRP of METAC. Controlled polymerization of
PEO45MEMA macromonomer was carried in 5% solution of a mixture of 2-propanol and
water at 35 oC. A series of poly-PEO45MEMA with molecular weight Mn ranging from 300
000 to 500 000 was synthesized. Unfortunately, an attempt to polymerize METAC by AGET
ATRP from poly-PEO45MEMA as a macroinitiator failed.
Using another approach, AGET ATRP polymerization of cationic monomer METAC
was done first. The best results were achieved using tris[2-(dimethylamino)ethyl]amine
(Me6TREN) as a ligand, ascorbic acid as a reducing agent and methanol-water (85/15 wt/wt)
as a solvent. A series of poly-METAC with molecular weight Mn from 5 000 to 30 000 and
Mw/Mn (PDI) from 1.15 to 1.3 was synthesized. AGET ATRP of PEO45MEMA from polyMETAC as a macroinitiator was successful resulting in diblock copolymers poly-METAC-bpoly-PEO45MEMA with molecular weight Mn from 300 000 to 600 000 and polydispersity
index Mw/Mn from 1.5 to 1.8.
Acknowledgement. Financial support from the Research Council of Lithuania under the project MIP50/2010 is gratefully acknowledged.
References
1. S. S. Sheiko, B. S. Sumerlin, K. Matyjaszewski, Prog. Polym. Sci., 33, 759-785.
2. W. A. Braunecker, K. Matyjaszewski, Prog. Polym. Sci., 32, 93-146.
119
The Synthesis of purposive Phenanthrolinium Salts
S. Višniakova, A. Ţilinskas
Vilnius university, Naugarduko 24, LT-03225 Vilnius,
Lithuania
E-mail: [email protected]
The heterocyclic ammonium salts are useful synthons for constructing polycyclic systems [1].
The most popular used ammonium derivative is pyridinium salt [2]. Its derivatives are also
attracted attention because they have interesting properties and often react differently [3]. In
this work we studied synthesis of unsymmetrical phenanthrolinium bromides fused with
bicyclo[3.3.1]nonane system and their reactions with cyclic 1,3-dicarbonyl compounds.
Below is the general scheme of these reactions (1 scheme).
Ar
N
N
a)
N Br- N
O
O
+
+
b)
1
E
3
2
a) BrCH2C6H4NO2, CH3CN, toC
b) BrCH2COC6H5, CH3CN, toC
c) Et3N, CH3CN, toC
O
c)
Ar
Ar
N
N
N
N
+
O
E
O
E
O
4
5
1 scheme
Preliminary experiments showed that following reactions are applicable for synthesis of
unsymmetrycal phenanthrolines fused with bicyclo[3.3.1]nonane system. Although the yields
of polyheterocyclic systems were moderate, the simplicity of the procedure makes this
reaction very attractive.
The photophysical properties of synthesized compounds will be explored and presented.
References
1.
2.
3.
A. J. Winstead, N. Fleming, Molecules, 13 (2008) 2107-2113.
Satoshi Kojima, Kyoko Hiroike, Tetrahedron Lett., 45 (2004) 3565–3568.
J. L. Kristensen Tetrahedron Lett., 49 (2008) 2351–2354; L. G. Voskressensky, L. N. Kulikova,
Tetrahedron Lett., 51 (2010) 2269–2270; Hui Li, Chao-Guo Yan, Tetrahedron, 67 (2011) 2863-2869.
120
SYNTHESIS OF NOVEL 6-SUBSTITUTED-2,4-DIARYLAND 4,6-DISUBSTITUTED 2-METHYLTHIOPYRIMIDINES
1
A. Voitechovicius,1,2 K. Karpavicius,1 P. Adomenas,2 S. Tumkevicius1
Department of Organic Chemistry, Vilnius University, Naugarduko 24, LT-03225, Lithuania
2
Liquid Crystals Laboratory, Institute of Applied Research, Vilnius University,
Naugarduko 24, LT-03225,Lithuania
E-mail: [email protected]
In view of search of highly efficient light-emitting materials we report herein our results on
the synthesis of novel non-linear (so-called banana-shaped and star–shaped ) oligoarylenes of
a pyrimidine series (1-3) (Scheme 1).
The synthetic strategy for preparation of compounds 1, 2 was based on the palladiumcatalyzed cross-coupling reaction (Suzuki coupling) of the corresponding 4-chloro-6-methyl2-arylpyrimidines with arylboronic acids and following modification of 6-methyl group of the
obtained 2,4-diaryl-6-methylpyrimidines using their condensation reaction with various
aromatic aldehydes.
Scheme 1
Synthesis of compounds 3 was accomplished by the reaction of 4,6-dimethyl-2methylthiopyrimidine with 6-bromonicotinic aldehyde followed by the Suzuki coupling with
arylboronic acids. Some non-commercial arylboronic acids were synthesized by the reaction
of the corresponding arylmagnesium halides with trimethylborate and subsequent hydrolysis
of the formed dimethylboronates.
Photophysical properties of the synthesized compounds will be presented, as well.
121
EQCN STUDY OF ELECTROCHEMICAL MODIFICATION OF BISMUTH SULFIDE
FILMS IN THE Co2+ CONTAINING ELECTROLYTE
A. Ţielienė, L. Tamašauskaitė-Tamašiūnaitė, L. Naruškevičius, B. Šimkūnaitė-Stanynienė,
A. Sudavičius, V. Pakštas
State Research Institute, Center for Physical Sciences and Technology, Istitute of Chemistry,
A. Goštauto 9, LT-01108 Vilnius, Lithuania
E-mail: [email protected]
Thin films of bismuth sulfide show promise for application as photovoltaic
converters, optoelectronic and thermoelectric devices, and photodiode arrays. Currently they have
been used as a conductive sublayer in direct electrochemical metallization of dielectrics. For this
purpose bismuth sulfide is usually formed using the successive ionic layer adsorption and
reaction (SILAR) method. It was shown that the bismuth sulfide can be easily modified in nickel
and zinc plating electrolytes [1-3]. The present work is a continuation of our previous studies.
The aim of this study was to investigate in more detail the electrochemical behaviour and
possibility of modification of bismuth sulfide films with cobalt. The electrochemical reduction of
bismuth sulfide thin films as-deposited on Au using the SILAR method has been investigated in
the Co2+ free background and Co2+ containing electrolytes at different pH values by means of
electrochemical quartz crystal nanobalance coupled with cyclic voltammetry. The resulting cobalt
modified bismuth sulfide film surfaces were characterized by X-ray photoelectron spectroscopy
and scanning electron microscopy.
It has been determined that the bismuth sulfide film initiates the Co2+ ions reduction
prior to the traditional overpotential deposition of it. The processes occurring during the
reduction of bismuth sulfide film in the Co2+ containing electrolyte depend on the
electroreduction medium. At pH 5 it occurs at more negative potential values and the observed
mass changes due to cobalt electrodeposition are greater than that at pH 3. A more detailed
investigation of cobalt deposition has been carried out under the potentiostatic conditions. The
data obtained confirm that the reaction mechanism depends on solution pH: at pH 3 the
predominant reaction is reduction of bismuth sulfide to Bi while at pH 5 the predominant reaction
is the reduction of Co2+ ions.
The XPS analysis confirms the incorporation of cobalt into the bismuth sulfide film
during the reduction of bismuth sulfide film in the Co2+ containing solution at pH 3 and 5: both
on the film surface and at a film depth of 2 nm cobalt and oxy/hydroxy cobalt compounds were
detected. When bismuth sulfide film modified with Co was annealed at 200 0C, a ternary sulfide
was not formed in contrast to the Ni modified bismuth sulfide film, when a metal-rich mixed
sulfide Ni3Bi2S3 (parkerite) was obtained, which possesses a markedly higher conductivity [1].
The proposed method can be applied for cobalt electrodeposition on dielectrics,
using thin bismuth sulfide films as an activator.
References
1.
2.
3.
G. Valiulienė, A. Ţielienė, B. Šimkūnaitė, L. Naruškevičius, L. Tamašauskaitė Tamašiūnaitė, V. Pakštas, A.
Selskis, J. Solid State Electrochem., 14 (2010) 203-212.
L. Tamašauskaitė Tamašiūnaitė, B. Šimkūnaitė-Stanynienė, L. Naruškevičius, G. Valiulienė, A. Ţielienė, A.
Sudavičius, J. Electroanal. Chem., 633 (2009) 347-353.
L. Naruškevičius, B. Šimkūnaitė-Stanynienė, G. Valiulienė, A. Ţielienė, L. Tamašauskaitė Tamašiūnaitė, A.
Sudavičius, Trans. IMF, 87 (2009) 303-308.
122
International Session on Nanomaterials:
fabrication, characterisation and applications
October 14th, Friday
Venue: Lithuanian Academy of Sciences.
Organising Committee
Valentinas Snitka, Chairman
Artūras Ulčinas
Carles Canes
Harri Lipsanen
Mervyn Miles
Ingrida Bružaitė
Contributors:
EU FP7 NANOMAT project, Research Center for Microsystems and
Nanotechnology, Kaunas University of Technology
Scope of the Scientific session: to stimulate the scientific exchange and collaboration on
instrumentation and applications of nanotechnology in the materials and life sciences.
The meeting creates an environment to discuss current developments and to generate new ideas.
123
BREAKING THE SPEED LIMIT IN AN AFM
- WITH A LIGHT TOUCH
L. Picco, R. Harniman, M. Antognozzi, A. Ulcinas, O. Payton, D. Engledew, D.
Carberry, D.B. Phillips, J. Grieve, J. Vicary, M. Padgett*, M.J. Miles
Centre for Nanoscience & Quantum Information,
H.H. Wills Physics Laboratory,
University of Bristol,
Bristol, BS8 1TL,
UK
*Department of Physics & Astronomy, Glasgow University, Glasgow G12 8QQ, UK
For the characterisation of nanoscale structures of materials, scanning probe microscopy
(SPM) and atomic force microscopy (AFM) in particular are the main tools. In the case of
AFM, this is a result of its versatility in providing three-dimensional images in a great variety
of environments. However, some aspects of AFM can limit its application to particular types
of samples.
There are three areas in which conventional AFM has limitations: (i) low imaging rate, (ii)
probe-sample force interaction, and (iii) the planar nature of the sample.
We are developing two techniques for high-speed force microscopy. One high-speed AFM
(HS AFM) technique is a DC method in which the tip is in continuous contact with the
specimen. This routinely allows video-rate imaging (30 frames per second, fps) and a
specially developed version of this instrumentation has allowed imaging at over 1000 fps, i.e.,
100,000 times faster than conventional microscopes. Damage to specimens resulting from
this high-speed contact-mode imaging is surprisingly very considerably less than would be
caused at normal speeds. The nature of tribological forces at the nanoscale and high shear
rates is of great interest in general and in this new technique in particular. Considerable
progress has been made recently in measuring and calculating the behaviour of the cantilever
and tip at these high-speeds, in order ultimately to design a better cantilever. The other highspeed force microscope is a non-contact method based on shear-force or transverse dynamic
force microscopy (TDFM). In this HS TDFM, the vertically-mounted laterally-oscillating
probe detects the sample surface at about 1 nm from it as a result of the change in the
mechanical properties of the water confined between the probe tip and the sample. With this
technique, very low forces are applied to the specimen resulting in negligible distortion.
Movies in which imaging of biomolecular structures at several frames/second in non-contact
will be presented.
The final limitation of requiring the sample to be planar is so engrained in the operation of
SPM that it is usually not recognized as a constraint. In a conventional AFM, as the tip and
cantilever scan over the surface of a sample they are displaced essentially only in the
direction perpendicular to the sample. It is as if the tip is only seeing the sample from one
direction. For example, it is unable to „look‟ at the sides of structures on the sample. We
have recently constructed an AFM in which the tip is the end of a nanorod that is steered in
three dimensions with five or six degrees of freedom. This allows the nanorod to be scanned
over and detect the sample surface from any direction such that it is capable of scanning
around 3D structures. The first images from this new instrument will be presented.
124
COMBINING SCANNING PROBE AND OPTICAL MICROSCOPY TECHNIQUES
J.K.H. Hoerber
HH Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, UK
In the last 25 years, the Atomic Force Microscope (AFM) emerged as a powerful technique
for biological research giving ultra high-resolution structural information and allowing
measurements of molecular forces at the single molecule level. An important aspect for AFM
studies on living cells from the very beginning was the integration of the instrument into an
optical microscope. Furthermore, a combination of several techniques in one instrumental setup is desirable to reduce the problems caused by variations in sample preparations.
However, living cells are 3-D structures and the AFM is a surface tool with its performance
directly coupled to the flatness of the surface investigated. Imaging inside cells is impossible
due to the mechanical connection of the instrument with the imaging tip. Therefore, a
scanning probe microscope without a mechanical connection to the tip like the Photonic Force
Microscope (PFM) is an ideal complementary technique for cell biological research. In the
PFM the mechanical cantilever is replaced by the 3-D trapping potential of a laser focus
holding a nanometer sized particle used as the tip. This opens up many new ways of
measuring interactions with 3D structures and to develop particle sensors for optical and
chemical sensing of material properties on the nanometer scale.
125
EFFECT OF ANNEALING ON THE ELECTRICAL CHARACTERISTICS
OF CNT BASED TRANSISTORS WITH ALUMINA COATING
K. Grigoras
Department of Materials Science and Technology, Aalto University,
P.O.Box 13500, FI-00076 Aalto, Finland
E-mail:[email protected]
Atomic layer deposition (ALD) offers perfect uniformity and conformality of the film, even in
the case of complicated surfaces and high-aspect-ratio structures. Also, the layer thickness can
be controlled in the nanometer range [1, 2]. Ald is successfully applied in carbon nanotube
(CNT) basee device fabrication [3]. In this work we are presenting results on the annealing of
alumina (aluminium oxide) films grown by ALD. Main attention is paid to the electrical
characteristics of CNT network based field effect transistors with alumina coatings. A local
delamination of the films is observed after treatment at temperatures above 400 oC (figure1).
Changes of the electrical conductivity type is measured on transistors with different coating
thicknesses, as well as after annealing devices at different temperatures (figure 2). Results can
be important for device operation at critical conditions, such as high temperature.
Figure 1. SEM pictures showing delamination of aluminum oxide layer form the Si/SiO 2 substrate.
Ug [V]
a
b
c
Figure 2. Transistors source-drain current dependences on gate voltage: without coating (a), after coating with
100 nm of alumina (b), and after annealing it at 600oC (c). Conductivity type changes from p-type (a) into
ambipolar (b) and returns back (c).
References
1.
2.
3.
M. Leskelä and M. Ritala, Angew. Chem. Int. Ed., 42 (2003) 5548.
K. Grigoras, V-M. Airaksinen, and S. Franssila, J. Nanosci. Technol., 8 (2009) 3763.
M.Y. Zavodchikova et al, Nanotechnol., 20 (2009) 085201.
126
SURFACE PLASMON RESONANCE AT THE NANOSCALE:
HOW DOES THAT WORK?
B. A. Snopok
V.Lashkaryov Institute of Semiconductor Physics,
National Academy of Sciences, 41 Prospekt Nauki, 03028 Kyiv, Ukraine
E-mail: [email protected]
The surface plasmon resonance (SPR) phenomenon is a basis of many optical nondestructive
analytical techniques. Both the propagating and localized surface plasmon excitations are
electromagnetic waves coupled to charge fluctuations, and are pinned to the interface between
a metal and a dielectric. The main advantage of the SPR technique is possibility of direct
registration of surface interactions without any additional labels. However, application of
SPR-based methods to the monitoring of nanostructures with lateral dimensions in nanoscale
range often run into problems. This results from the fact that propagation length for p-SPR is
normally in micron range for usially using metals like gold or silver.
In general, an optoelectronic technique measuring parameters other than simple reflection
may yield more information on interfacial structure as measurements (intensity, polarization,
and Stokes factors) of evanescent wave light scattering depend strongly on variation of
permittivity within interfacial architectures in nanometer scale and, consequently, on the
presence of different spatial organization of foreign molecules [1]. In line with that a novel
SPR based technique to detect processe specific for nanometer scale is discussed (see Figure).
The technique involves measuring scattered light under surface plasmon resonance conditions
[2]. It was shown that the maximum scattering angle correlates with the traditionally
employed reflection minimum. Panoramic scanning of scattered light under SPR conditions
has all the functional advantages of the SPR technique and open the way for detection of
nanoscale structures with lateral dimentions in nanoscale range [3]. In addition, the proposed
technique simplifies device design, increases the dynamic range of analysis, and integrates
data with those from surface-plasmon field-enhanced fluorescence spectroscopy.
References
1.
2.
3.
S.I.Lysenko, B.A.Snopok, V.A.Sterligov, Optics and spectroscopy, 188 (2010) 618-628.
A.Savchenko, E.Kashuba, V.Kashuba, B.Snopok, Analytical Chemistry, 79 (2007) 1349-1355.
A.Savchenko, E.Kashuba, V.Kashuba, B.Snopok, Sensor Letters, 6 (2008) 705–713.
127
AFM MAPPING OF BIOMOLECULAR FORCE AND SURFACE INTERACTIONS:
APPLICATIONS IN BIOLOGY AND GEOCHEMISTRY
T. McMaster
H. H. Wills Physics Laboratory, University of Bristol, Bristol Centre for Functional Nanomaterials,
UK
128
SURFACE CHEMISTRY MAPPING WITH TIP-ENHANCED RAMAN
MICROSCOPY
V. Snitka
Research Center for Microsystems and Nanotechnology, Kaunas University of Technology,
Studentu 65, Kaunas 51369, Lithuania
E-mail: [email protected]
Due to diffraction limit, the lateral resolution achieved in standard microscopic Raman measurements
cannot be better than about a few hundreds of nanometers. This restriction of Raman spectroscopy has
been overcome by Zenobi et al. [1] , who showed, that when a fine tip made of a metal that supports
surface plasmon resonances is brought within a nanometer range to a sample, a strong enhancement of
Raman signal from molecules being in the close proximity to the tip is observed and tip-enhanced
Raman spectra (TERS) achieved lateral resolution is less than 10 nm. Moreover, TERS has the
potential to achieve angstrom resolution for tips of 1 nm radii. However, one of the major difficulties
of TERS is the low reproducibility of the Au or Ag-vapor coated tip.
In this work the current status and challenges of the TERS development are presented. As a solution
of cantilever for TERS, a novel bulk gold tapping mode cantilever and application for TERS will be
demonstrated. The cantilever fabrication procedure is similar to the one adopted by Macpherson et al
[2]. A gold microwire purchased from Goodfellow was flattened against two flat silicon surfaces
producing the cantilever force sensor. One of the extremities of the wire, left without being flattened,
was bent at 90º resulting in the future tip. This cantilever was glued to a standard silicon chip, equal to
the ones used to hold commercial cantilevers. The tip extremity was both shortened and sharpened by
electrochemical etching. The obtained cantilever had a length of 250 µm, average thickness of 33 µm
and average width of 75 µm. The TERS system was built on NT-MDT Spectra platform [3].
In Fig.1 are shown Raman spectra for TERS and micro-Raman at the same intensity scale. Large
exposition times would have risked the CCD camera while measuring in TERS mode, thus for the
sake of comparison between tip-enhanced and micro-Raman the exposition time was limited to 0.5 s.
It is clear the high enhancement was induced by the bulk gold tip at the same time the gold cantilever
allows to achieve the atomic step resolution on AFM imaging of graphene.
Fig.1. TERS of graphene obtained with bulk gold cantilever in tapping mode.
References
1. R.M. Stockle, Y.D. Suh, R. Zenobi, Nanoscale analysis by Tip-enhanced Raman Scattering, Chem. Phys.
Lett. 318 (2000) 131.
2. V. Macpherson, P. R. Unwin, Combined Scanning Electrochemical-Atomic Force Microscopy, Analytical
Chemistry 72 (2000) 276-285
3. http://www.ntmdt.com/device/ntegra-spectra
129
FEELING THE SQUEEZE: SHEAR VISCOELASTICITY OF NANOCONFINED
WATER
A. Ulčinas, 1 G. Valdre,2 V. Snitka,1 M. J. Miles,3 P. M. Claesson,4 and M. Antognozzi3
1
Research Centre for Microsystems and Nanotechnologies, Kaunas University of Technology,
LT-51369 Kaunas, Lithuania
Email: [email protected]
2
Department of Earth and Geoenvironmental Sciences, University of Bologna, I-40126
Bologna, Italy
3
H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL and Nanoscience and
Quantum Information Centre, University of Bristol, Bristol BS8 1FD, UK
4
Department of Chemistry, Surface and Corrosion Science, Royal Institute of Technology, SE100 44 Stockholm, Sweden
How water molecules confined in nanometer gaps respond to shear: as a viscoelastic solid, a
viscous fluid or something in between? This important question relevant in tribology,
colloidal science and biology, continues to be debated, with experimental evidence provided
for conflicting points of view.
Here we describe the results obtained using innovative technique based on vertically oriented
micromechanical force sensors [1, 2] investigating viscoelastic response of nanoconfined
water. By conducting measurements in high acidity and high ionic strength conditions, we
show that surface-adsorbed cations play an important role in viscoelastic shear response of
water confined in a gap of less than 1 nm on muscovite mica surface.
References
1. M. Antognozzi, A. Ulcinas, L. Picco, S. H. Simpson, P. J. Heard, M. D. Szczelkun, B. Brenner, and M. J.
Miles, Nanotechnology 19 (2008) 384002.
2. T. Scholz, J. A. Vicary, G. M. Jeppesen, A. Ulcinas, J. K. H. Hoerber, M. Antognozzi, Nanotechnology 22
(2011) 095707
130
SILICON NANOGRASS FOR IMPROVED GALVANIC CONTACT TO MICRO FUEL
CELL GAS DIFFUSION LAYER
G. Scotti1,2, M. Mäkinen2,P. Kanninen3, T. Kallio3 and S. Franssila2
Department of Micro and Nanosciences, Aalto University, Espoo, FINLAND
2
Department of Materials Science and Engineering, Aalto University, Espoo, FINLAND
3
Department of Chemistry, Aalto University, Espoo, FINLAND
1
Silicon nanograss is a surface morphology of silicon reactively etched in passivating SF6/O2
conditions. It is a near-random series of pyramidal structures up to 2 μm tall, with a base about
300 nm wide (Figure 1). The authors have previously studied black silicon as a micro fuel cell
(MFC) gas diffusion layer (GLD) [1]. In this abstract we focus our attention on the improved
electrical contact between the silicon current collector and a mesh-like material such as carbon
cloth, which now acts as GDL.
Figure 2 illustrates the construction of a MFC: the silicon chips have a flowfield consisting of an
array of 200x200μm2 square pillars, 50μm tall and separated by 100μm wide channels. This
flowfield is recessed 50μm below the plane of the chips, and it is then etched to create the black
silicon surface. A commercial carbon cloth with platinum catalyst is placed inside the recess, and
a Nafion® membrane is inserted between two silicon-carbon cloth assemblies.
To determine the effectiveness of silicon nanograss, both samples with and without silicon
nanograss were prepared and characterized by sweeping a voltage from an open-circuit value
down to 0.1 V, with hydrogen as fuel, at 20°C. Compared to no-silicon nanograss, a clear
increase in maximum current and power density is was observed. The MFCs without black
silicon achieved a maximum power density of 30 mW cm-2, compared to 63 mW cm-2, obtained
with the device with black silicon. The results obtained are comparable to some of the best
hydrogen micro fuel cells [2][3], validating the use of silicon nanograss to improve the galvanic
contact between silicon substrate and a carbon mesh.
Figure 1.AFM scan of silicon nanograss.
Figure 2: Construction of a silicon chip with carbon
cloth and structure of the assembled MFC.
References
[1] G. Scotti, P. Kanninen, M. Mäkinen, T. Kallio, S. Franssila, Micro Nano Lett., Vol. 5, Iss. 6 (2010), 382-385
[2] N. Kuriyama, T. Kubota, D. Okamura, T. Suzuki, J. Sasahara, , Sens. Actuators, A, 145-146 (2008), 354-362
[3] Z. Xiao, G. Yan, C. Feng, P. C. H. Chan, I. M. Hsing, J. Micromech. Microeng. Vol. 16 (2006), 2014-2020
131
CHEMICAL IMAGING AND GRAPHENE-ENHANCED RAMAN SPECTROSCOPY
OF TIO2 NANOPARTICLES
D. Naumenko1, V. Snitka1, H. Lipsanen2
Kaunas University of Technology, Studentu 65, LT-51369 Kaunas, Lithuania
2
Aalto University School of Electrical Engineering, Tietotie 3, 02150 Espoo, Finland
[email protected]
1
The aim of this work was to investigate the TiO2 nanoparticles Raman response depending on
the graphene properties.
The physical-chemical characterization of nanoparticles (NPs) has been one of the main
research areas in nanotechnology where high sensitivity and short measurement time are
highly sought goals. Raman spectroscopy has been for years a standard tool for chemical
analysis although the long acquisition time usually required limits its application [1]. Using
graphene we report on its application as a substrate to analyse nanoparticles in the so-called
surface-enhanced Raman spectroscopy (SERS) mode. As a proof of concept it is
demonstrated the capabilities and limitations of graphene to enhance the Raman signal of
TiO2 NPs of technological interest. It is shown that the main issues of Raman like long
acquisition time can be overcome using graphene as SERS support. At the excitation
wavelength used (λ=632.8 nm) plasmon excitation in graphene does not take place in the
contrast to conventional SERS substrates based on noble metals; therefore a chemical
mechanism is invoked to explain the enhancement observed [2].
The graphene sheets on the glass supports have been prepared by mechanical exfoliation of
graphite or by transfer from the copper of big area CVD graphene sheets. The commercial
TiO2 NPs powder was used to be deposited on the graphene surface from a water colloid
solution. The NPs were preliminary characterized by AFM and XRD.
We have obtained a higher enhancement of the Raman signal on the graphene flakes
comparing to CVD graphene. To analyse an influence of graphene properties on NPs Raman
response, the main phonon bands of CVD graphene (D, G, 2D) were measured
simultaneously with the chemical imaging of TiO2 NPs on graphene sheet. It seems that the
higher enhancement on graphene flakes can be explained by the strongest value of D-band. It
was obtained also that the TiO2 NPs Raman signal increases with the increasing of CVD
graphene D/G bands ratio that confirms the charge transfer from graphene to TiO2 NPs [3].
Figure 1. a) Raman spectra of anatase TiO2 NPs on the glass support and graphene flake demonstrating the
potential of graphene for surface-enhanced Raman spectroscopy of NPs. b) Raman imaging of TiO2 NPs on
CVD graphene/glass substrate (33x33µm). The strongest band of TiO 2 (around 150 cm-1) was chosen for its
“fingerprint”. c) The increasing of TiO2 Raman signal depending on the graphene D to G bands ratio.
References
1. T. Deckert-Gaudig, E. Bailo, V. Deckert. Journal of Biophotonics, 1 (2008) 377-389.
2. X. Ling, L. Xie, Y. Fang, H. Xu, H. Zhang, J. Kong, M.S. Dresselhaus, J. Zhang, Z. Liu. Nano Letters, 10
(2010) 553-561.
3. B. Das, B. Choudhury, A. Gomathi, A.K. Manna, S.K. Pati, C.N.R. Rao. Chem. Phys. Chem., 12(5) 2011
937–943.
132
HIGH SPEED, HIGH THROUGHPUT, SPM IMAGING AND NANOMECHANICS
S. C. Minne, L. Mininni, A. Slade, S. Hu, J. Kindt, H. Stadler, and C. Su.
Bruker Nano Surfaces
Santa Barbara, CA – 93117, USA
The AFM has long been recognized for its ability to both image surfaces and determine
mechanical properties at the nanoscale. However, until recently, the combination of these two
capabilities was often a compromise between achievable imaging rate, and the amount or
quality of material property data collected.
In this talk we present advances in each of these areas: 1) a new microscope which, for the
first time, enables high speed (10x to 100x) large area scanning of large samples, and 2) a
new way to control the atomic force microscope to acquire mechanical properties at the
nanometer scale (modulus, adhesion, deformation, dissipation).
The high-speed AFM is novel in that it is a large area “scanning-tip” design, which
implements small fast cantilevers. This configuration eliminates nearly all sample constraints,
allowing virtually any sample to be simply imaged at high speeds. Videos of various samples
scanned in both air and fluid will be presented. The system is also used with a novel control
process that directly measures the instantaneous force interaction during each tapping cycle,
and this information is used to directly control the tip-surface interaction down to 10pN.
133
AFM-RAMAN-SNOM AND TIP ENHANCED RAMAN STUDIES OF MODERN
NANOSTRUCTURES
P. Dorozhkin, A. Shchokin, E. Kuznetsov, V. Bykov, I. Bykov
NT-MDT Co., Build. 100, Zelenograd Moscow, 124482 Russia
E-mail: [email protected]
We demonstrate instrumental realization and various applications of Atomic Force Microscopy
integrated with Confocal Raman/Fluorescence/Rayleigh microscopy and Scanning Near Field Optical
Microscopy (SNOM) produced by NT-MDT. Results on various samples are demonstrated: graphene,
carbon nanotubes, semiconductor nanowires, quantum dots, nanodiamonds, plasmonic waveguides,
photonic crystal optical fibers, various biological objects etc. For example, graphene on gold is
investigated by different AFM and spectroscopy techniques providing comprehensive information
about the sample. We study in details how the thickness (number of monolayers) in graphene affects
its physical properties: surface potential (work function), local friction, elastic modulus, capacitance,
conductivity, charge distribution, Raman and Rayleigh light scattering etc. Results for graphene flakes
are qualitatively compared to those for carbon nanotubes of different diameters. We show how
electrostatic charging of graphene flakes can be effectively measured and modified by AFM cantilever.
Studies are performed both in ambient air conditions and in controlled atmosphere and humidity.
c
b
d
e
f
h
i
j
g
Fig. a), b). AFM – Raman configuration: schematics (a) and white light image (b); Raman laser is tightly (400 nm spot diameter)
focused onto the very end of a “nose”- shaped AFM cantilever using 100x objective; Graphene layer is positioned below the
cantilever and under the laser spot; while scanning the sample, AFM and Raman data is obtained simultaneously.
c) – g). Various AFM images characterizing different physical properties of the sample - Topography (c), Electrostatic Force (d),
Force Modulation (elastic properties) (e), Kelvin Probe (f), Lateral Force (g).
h) – j). Confocal optical images – Rayleigh light (h), Raman 2D band mass center (i), Raman G band intensity (j).
The ultimate goal of integrating AFM with Raman/fluorescence spectroscopy is to break diffraction
limit and to bring spatial resolution of optical methods down to resolution of AFM (a few nm). We
also present results of Tip Enhanced Raman Spectroscopy (TERS) or “nano-Raman” mapping realized
using integrated AFM-Raman system. Measurements are realized in two different excitation
configurations: Inverted (for transparent samples) and Upright (reflected light configuration, for
opaque samples, with side illumination option). In both geometries we demonstrate near field Raman
enhancement effect due to resonant interaction of light with localized surface plasmon at the apex of a
metal AFM probe. Various samples are studied by TERS technique: thin metal oxide layers, fullerenes,
strained silicon, carbon nanotubes, graphene. Actual plasmonic and near field nature of the Raman
enhancement is proven by a number of ways: dependence of the enhancement on the excitation
wavelength and polarization, enhancement versus tip-sample distance curves, observation of selective
enhancement of Raman signal from thin surface layers of the sample etc. Finally, the ultimate
performance of TERS is demonstrated by measuring Raman 2D maps with subwavelength lateral
resolution (down to 14 nm) – determined not by the wavelength of light, but by the localization area of
the surface plasmon electromagnetic field. We discuss current progress in manufacturing reliable
TERS probes.
134
INVESTIGATION OF STRUCTURAL AND CHEMICAL CHANGES IN
SACCHAROMYCES CEREVISIAE YEAST CELLS BY AFM AND RAMAN
SPECTROSCOPY
I. Bruţaitė2, D. Naumenko1, V. Snitka1, E. Servienė2,3
1
Research Center for Microsystems and nanotechnology, Kaunas University of
Technology, 65 Studentu Str.LT-51369, Kaunas, Lithuania
2
Vilnius Gediminas Technical University, Deparment of Chemistry and
Bioengineering, 11 Sauletekio al.,LT-10223 Vilnius, Lithuania,
3
Nature Research Centre, Akademijos 2, Vilnius, Lithuania
The Raman spectroscopy of biological tissues and cells is useful and important in the fields
of medical and biological diagnosis. It is a label-free technique for generating unique spectral
fingerprints from microorganisms. On the other hand using of gold AFM cantilevers in the
combination with Raman leads to excitation of surface plasmon resonance on metallic surface
and enhancement a quite weak Raman signal in biological samples.
The aim of this work was to analyze the Saccharomyces cerevisiae yeast cells using the
Micro-Raman and Tip-enhanced Raman (TERS) spectroscopy together with Atomic force
microscopy (AFM) to monitor the changes in the cells membrane morphology and chemical
mapping of mermbrane structure.
In this work the differences of the cell membranes of Saccharomyces cerevisiae parental and
the modified strains were identified using Micro-Raman and TERS spectroscopy. AFM was
used to evaluate the life-form, shape and size of the yeast Saccharomyces cerevisiae cells, as
well as the cell membrane surface topographical differences between the parental strain
21PMR MAT leu2 ura3-52 [kil-0] and its transformant 21PMR-[YEpsec1-GDH-ab]
synthesizing membraneous protein GDH-ab.
Raman investigations were done using NTEGRA Spectra system (NT-MDT Inc.) on both
inverted and upright configurations (with 100x high NA objectives and bulk gold cantilevers
for TERS measurements) at the excitation wavelength of 632.8 nm and the controlling laser
power in the range of 0.07-70 mW. We have observed sufficiently strong fingerprint region
bands at 900, 1100, 1180, 1280, 1450, 1650, 1875, and 2900 cm-1.
AFM investigations have shown a substantial differences in the parental and genetically
modified cells membrane morphology. The forced displacement measurements have been
used to identify the difference in mechanical properties of the parental and modified cells.
The obtained results indicate that Raman spectroscopy combined with AFM can be used for
fingerprinting of different yeast strains and structural analysis of cellular compartments.
References
1. P. Rösch, M. Harz, M. Schmit, J. Popp. Journal of Raman spectroscopy, 2005, 36: 377-379.
2. E. Burattini, M. Cavagna, r. Dell‟Anna, F. Malvezzi campegge, F. Manti, F. Rossi, S. Torriani. Vibrational
Spectroscopy, 2008, 47: 139-147.
3. C.M. Creely, G.P. Singh, D. Petrov. Optics Communications, 2005, 245: 465-470.
4. V. Turov, V. M. Bogatyrev, V. I. Zarko, S. P. Gorbik, E. M. Pakhlov, R. Leboda, O. V. Shulga, A. A.
Chuiko. Journal of Colloid and Interface Science, 2005, 283: 329-343.
135
SYNTHESIS OF SILVER NANOPARTICLES USING PHYTOEXTRACTS FROM
HIGHER PLANTS
Ya. Pirko1, I. Danylenko1, O.Kolomys2, P. Smertenko2, V.Strelchuk2, Ya.B. Blume1
1
Institute of Food Biotechnology and Genomics, Natl. Acad. of Sci. of Ukraine,
Osypovskogo str., 2a, Kyiv, 04123, Ukraine
E-mail: [email protected]
2
Institute of Semiconductor Physics named V.E. Lashkaryov, Natl. Acad. of Sci. of Ukraine,
pr. Nauki, 41, Kyiv, 03028, Ukraine
E-mail: [email protected]
Nanoparticles are attracting a great deal of attention because of their potential biological,
pharmaceutical and many other aspects of their potential applications [1, 2]. Today there are
several different approaches to synthetase nanoparticles. The chemical and physical methods
are the most popular. However, the chemical approaches of the synthesis of nanoparticles are
not always spared from the necessity to use toxic substances. The physical methods are often
very expensive. Chemical synthesis methods may still lead to the presence of some toxic
chemical species adsorbed on the surface that may have adverse effects in medical
applications. Biological methods of synthesis of nanoparticles (using microorganisms, cell
culture, plant tissue or phytoextracts) were proposed as possible environmentally safe
methods which are alternatives to existing chemical and physical methods of nanoparticle
synthesis [3, 4]. While microorganisms such as bacteria, actinomycetes, and fungi have long
been used in synthesis of metal nanoparticle, the use of plants in similar nanoparticle
synthesis techniques is relatively unexplored [5].
The silver nanoparticles were synthesized from solution of AgNO3 using the phytoextracts of
Magnolia denudata and M. stellata. Phytoexstrakts were obtained in two ways: by grinding
plant material (leaves) in liquid nitrogen and subsequent removal of debris by centrifugation,
as well as by boiling. Nanoparticles were purified after reaction from the excess of the
phytoextract three times by centrifugation and resuspension of sediment. The sloping peak
absorption of the mixture at a wavelength of 425-435 nm corresponded the absorption of
silver nanoparticles. The nanoparticles which were synthesized were stable in solution during
long time (2 weeks). The spectral characteristics of a colloidal solution of purified
nanoparticles were not changed during 2 weeks after their synthesis. The influence of light
and temperature on formation of silver nanoparticles was studied. It was found that light can
accelerate the process of nanoparticle synthesis as well as also can change their size. Silver
nanoparticles obtained in the experiment were studied by Raman and FTIR spectroscopy and
transmission electron microscopy.
References
1.
2.
3.
4.
5.
I.Brigger, C. Dubernet, and P. Couvreur, Adv. Drug Delivery Rev., 54 (2002) 631–651.
X. Wu, H. Liu, J. Liu, K. N. Haley, J. A. Treadway, J. P. Larson, E. Ge, F. Peale, and M. P. Bruchez, Nat.
Biotechnol. 21(2003) 41–46.
D. P. Debecker, C. Faure, M.-E. Meyre, A. Derre, E. M. Gaigneaux, Small, 4 (2008) 1806–1812.
A. Ahmad, P. Mukherjee, D. Mandal, S. Senapati, M. I. Khan, R. Kumar, M. Sastry, J. Am. Chem. Soc.,
124 (2002) 12108-12109.
S. Shankar, A. Rai, A. Ahmad, M. Sastry, J. Colloid and Interface Sci., 275 (2004) 496–502.
136
FABRICATION OF INTERFACIAL GOLD NANOSTRUCTURES BY SIZECONTROLLED CHEMICAL ETCHING
P. M. Boltovets, S. A. Kravchenko, B. A. Snopok
V.Lashkaryov Institute of Semiconductor Physics,
National Academy of Sciences, 41 Prospekt Nauki, 03028 Kyiv, Ukraine
E-mail:[email protected]
Development of soft chemical processes for the synthesis of interfacial architectures with
well-defined structural nano-motifs organized over large areas in two dimensions is an
important branch of nanotechnology. The present study deals with the fabrication of gold
nanostructures using size-selective chemical etching of continuous gold films on glass support
with titanium and chromium adhesive layers. In this process, which is called self-passivated
surface etching, a gold film is etched in the presence of citric acid, resulting in gold
nanostructures adhering to the metal support. The size-controlled chemical dissolution of gold
is driven by a competing reaction between self-organized passivation of surface nano-motifs
by citric acid shells and soft etching by a nonoxidative composition containing hydrochloric
acid and hydrogen peroxide in water.
Figure demonstrates general concept of the size-controlled chemical etching of gold surfaces
in the presence of citric acid. Scheme illustrates the interfacial equilibrium of gold atoms at
the nanostructured surface. Typical packing of citric acid in crystalline lattice is shown in
right top corner.
According to obtained results, the presence of a chemically stable adhesive layer (titanium),
citric acid in solution, and agitation are critical factors to be considered. However, the nature
of the adhesive layer is the most influential factor. The following technique presents a simple
method for the rapid fabrication of a nanostructured gold substrate that has the ability to
support both propagatingon and localized surface plasmon resonances simultaneously.
References
1.
P. M. Boltovets, S. A. Kravchenko, B. A. Snopok, Plasmonics, 5 (2010) 395-403.
137
FUNCTIONAL ARCHITECTURES BASED ON GOLD NANOPARTICLES BOUND
TO THE SURFACE OF SILVER BY A COORDINATION BRIDGE
S. A. Kravchenko, A. Shanzer*, B. A. Snopok
V.Lashkaryov Institute of Semiconductor Physics,
National Academy of Sciences, 41 Prospekt Nauki, 03028 Kyiv, Ukraine
E-mail: [email protected]
*Weizmann Institute of Science, Rehovot 76100, Israel
E-mail: [email protected]
Methods for the preparation of ordered surface structures by means of controlled selfassembly of molecules on a surface have gained practical significance after the work of Lehn
et al., who demonstrated the feasibility of forming stable supramolecular complexes on
surfaces. Special interest is found in multilayer architectures, in which the layering process of
self-assembly results from formation of chemical bonds between functional groups of
individual layers by means of covalent or coordination bonding. The potential of this field has
not yet been fully exploited. New approaches may be sought for coordination-bound
supramolecular architectures yielding new materials for sensor technology, medical
diagnostics, and analytical biochemistry. In the present work, we examined the optical
properties of coordination-bound surface architectures, in which gold nanoparticles are
immobilized on a silver surface by means of a bridge structure containing Zr(IV) ions.
In the present work, we obtained multilayer surface structures by means of coordination
binding of the gold nanoparticles with the silver surface by Zr(IV) ions with subsequent
formation of a multilayer GNP structure. The structurized GNP/MPA-Zr-MPA/Ag surface
architecture displays a high absorption capacity in a broad spectral region due to interaction of
plasmon excitations of the silver surface and the gold nanoparticle film separated by a
dielectric d-metal ion bridge structure. Such ultrablack films deposited on a metal surface
permit a considerable improvement in the function of temperature sensors of radiation,
decrease the effects of scattered light in optical devices, and may be used in the preparation of
various apparatuses such as sunlight energy transducers, broadband radiation sensors,
superlight ultrathin thermopanels absorbing light in a broad spectral range.
References
1.
S. A. Kravchenko, A. Shanzer, B. A. Snopok, Theoretical and experimental chemistry, 46 (2010) 302-308.
138
SYNTHESIS OF NANO-CARBON BY THE ELECTROCHEMICAL DEPOSITION IN
LIQUID OF ALCOHOL
A. Štogrin1, I. Bruţaitė2
1
Research Center for Microsystems and nanotechnology, Kaunas University of
Technology, 65 Studentu Str.LT-51369, Kaunas, Lithuania
2
Vilnius Gediminas Technical University, Deparment of Chemistry and
Bioengineering,
11 Sauletekio al.,LT-10223 Vilnius, Lithuania,
Nano-carbon structures growth in liquid, is an assembly of carbon nano-particles using an
electrolyte, that is rich source of carbon and inert or catalytic electrodes. Advantage of this
method is relatively cheep production of nano-Carbon structures, which doesn‟t require any
special equipment with extremely high temperatures, or pressure. Carbon structures are
usually grown by arc-discharge technique [1, 2] or in CVD reactors [3, 4]. One of the first
teams to apply carbon nano-tube growth in organic electrolyte at room temperature used
relatively toxic electrolyte mix of methanol and benzyl alcohol [5].
In this work an electrochemical deposition technique has been employed to produce nanocarbon from organic solvent at room temperature. Silicon were employed as counter electrode
(anode) and shungite plate, the only natural material that contains fullerenes was a working
electrode (cathode). In this method 96 vol% ethanol ( C2H5OH ) was used as the electrolite.
The potencial difference applied between the anode and cathode was kept at 550V. A low
resistance (550 kΩ cm) was placed perpendicularly on the centre in the liquid. The electrical
current was by applying 1· 10-3 A through electrolite for a period of up 30 min to 180 min or
360 min. The deposition was carried out at room temperature and was employed to achieve
nano-carbon deposit on the cathode. The prepared samples were analyzed by AFM, SEM and
EDX. Analysis by AFM give structures like strip cluster about 520 nm. SEM show the
diameter of the strips are around 47-57 nm. Scanning the sample with EDX showed the
presence of carbon, silicon and oxygen.
Fig. SEM image of nano-carbon.
References
1. Iijima S, Ichihash T. Nature 1993; 363:603–5.
2. Bethune DS, Kiang CK, de Vries MS, Gorman G, Savoy R, VazquezJ, et al. Nature 1993; 363:605–7.
3. Amelinckx S, Zhang XB, Berbarerts D, Zhang XF, Ivanov V, Nagy JB. Science 1994;265:635–9.
4. Yacaman MJ, Yoshida MM, Rendon L, Santiesteban JG. Appl Phys Lett 1993;62:657–9.
5. D. Zhou, E. V. Anoshkina, L. Chow, G. Chai. Carbon, 2006, 44: 1013-1024.
139
THE INFLUENCE OF ZnO NANOPARTICLES ON THE VIABILITY
OF THE SACCHAROMYCES CEREVISIAE YEAST CELLS
S. Komarovskaja, I. Bruţaitė
Vilnius Gediminas Technical University, Deparment of Chemistry and
Bioengineering,
11 Sauletekio al.,LT-10223 Vilnius, Lithuania,
Nanosized metal oxide particles are receiving increasing attention for a large variety of
applications. Zinc oxide (ZnO) nanoparticles are included in beauty products, sunscreens.
Nano-powders such us ZnO have been found to exhibit marked antibacterial activity [1].
Whereas [2] suggested that the binding of ZnO particles to yeast cells surface due to
electrostatic forces kills the anaerobic organisms. The antibacterial activity of ZnO showed
capability to induce a reactive oxygen species (ROS). The aim of this work was to indentify
the toxicity of the ZnO nanoparticles for the Saccharomyces cerevisiae yeast cells. An
Atomic force microscope was used as an instrument to evaluate size and form of the ZnO
nanoparticles. Analysis by AFM indicated that ZnO Nps are spherical form and diameter is
about 33.5 nm. The yeast cells viability was studied using methylene blue dye in different
conditions and the UV–VIS absorption, luminescence spectra. The dye methylene blue took
up by the dead or severely damaged cells, but not by living cells. The optical absorption of
yeast cells was investigated in the wavelength rage from 300 to 670 nm.
Fig.2. Image of S. cerevisiae cells in an
indentical field stained by Methylene
blue: blue–non-viable, colourless –
viable.
Fig.1. UV-Vis spectra of S. cerevisiae cells.
The main absorption peaks were found 330, 540 and 620 nm. It was found a good correlation
between the concentration of dead cells and optical absorption. The increase in dead cells
concentration have shown a higher absorption. The luminescence from yeast cells have been
observed when the metabolism of cells was drastically altered. Luminescence spectra of
yeast cells have been investigated in the wavelength range from 470nm to 700 nm. The
higher dead cells concentration shows the higher emission intensity.
References
1. C. Hanley, J. Layne, A. Punnoose, K.M. Reddy, I. Coombs, K. Feris, D. Wingett. Nanotechnology, 19 (2008)
295-303
2. P. K. Stoimenov, R. L. Klinger, G. L. Marchin, K. J. Klabunde. Langmuir, 18 (2002) 6676-6686.