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Rosov pin 2014
SECOND REGIONAL
ROUNDTABLE:
REFRACTORY,
PROCESS INDUSTRY
AND NANOTECHNOLOGY
Programme and
The Book
of Abstracts
CENTER FOR INDUSTRIAL
AND TECHNOLOGICAL
DEVELOPMENT ”ANDREVLJE”,
FRUŠKA GORA,
SERBIA,
OCTOBER 23-24, 2014
Second regional roundtable: Refractory, process industry and
nanotechnology
ROSOV PIN 2014
Center for Industrial and Technological development ”Andrevlje”,
Fruška Gora, Serbia, October 23-24, 2014
Programme
and
The Book of Abstracts
Organised by:
Vinča Institute of Nuclear Sciences, Belgrade
Engineering Academy of Serbia, Belgrade
Lafarge BFC d.o.o. Beočin
REAL S d.o.o. Beograd
Title:
Second regional roundtable: Refractory, process industry and nanotechnology
ROSOV PIN 2014
Programme and The Book of Abstracts
Publishers:
Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Engineering Academy of Serbia, Belgrade, Serbia
Editor:
Vukoman Jokanović
Technical editor:
Božana Čolović
Sponsors:
LAFARGE BFC d.o.o. Beočin
REAL S d.o.o. Beograd
GALAX d.o.o. Donji Žabar, RS, BiH
BOMEX Invest d.o.o. Beograd
Printed in:
MP štampa, Novi Sad
Circulation: 100 copies
ISBN: 978-86-7306-125-2
Acknowledgement:
The Organizing and Scientific comities of ROSOV PIN 2014 are grateful to the Ministry of
Education, Science and Technological Development of the Republic of Serbia for financial
support.
Dear colleagues,
We are pleased to welcome you in the center “Andrevlje”, placed in the
hearth of beautiful mountain Fruška Gora, at the Second regional roundtable
“Refractory, process industry and nanotechnology”, ROSOV PIN 2014.
ROSOV PIN 2014 focuses on connecting different types of
nanotechnology with conventional technologies in refractory and process
industry. Nanotechnologies are not only present in modern high tech technology,
but also in conventional technology applied in the process industry and
refractory, giving the materials a completely new mechanical and corrosion
properties.
The roundtable is organized in three different parts: Refractory, including
the preparation of mineral raw materials; Process technology, including the
cement industry, glass industry, iron and steel and non-ferrous metallurgy; and
Nanotechnology, which covers the general principles of nanotechnology and its
place in the development of advanced refractories and ceramics in general,
powder metallurgy and carbon materials.
The desired intention of the organizers is to collect as many corporate
actors, including producers, consumers and providers of services in the field of
refractory and process industry in particular, and to open innovative ways of the
penetration of new technologies based on nanotechnology in various types of
process industry, in order to create entirely new products and to accelerate
technological progress in industries that are mostly present in our region.
Completely new approaches and technological concepts are welcome.
Have a nice time and a fruitful discussion with your colleagues from
scientific institutions and experts from the industry. We hope that you will
establish new connections which will lead to further efficient collaboration.
On behalf of the Organizing and Scientific Committee
Vukoman Jokanović
Scientific committee
Vukoman Jokanović, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Zlatko Rakočević, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Branko Nikolić, Engineering Academy of Serbia, Belgrade, Serbia
Mirko Gojić, Faculty of Metallurgy, Department for Physical metallurgy, Sisak, Croatia
Maja Dotour-Sikirić, Ruđer Bošković Institute, Zagreb, Croatia
Vesna Babić-Ivančić, Ruđer Bošković Institute, Zagreb, Croatia
Rebeka Rudolf, Faculty of Mechanical Engineering, Maribor, Slovenia
Ilija Nasov, Institute of Physics, St. Cyril and Methodius University, Skopje, Macedonia
Mira Vukčević, Faculty of Metallurgy and Technology, Podgorica, Monte Negro
Monika Jenko, Institute of Metals and Technology, Ljubljana, Slovenia
Tatjana Volkov Husović, Faculty of Technology and Metallurgy, Belgrade, Serbia
Branko Bugarski, Faculty of Technology and Metallurgy, Belgrade, Serbia
Ljubiša Andrić, Institute for Technology of Nuclear and Other Mineral Raw Materials,
Belgrade, Serbia
Amir Baraković, Faculty of Mining, Geology and Civil Engineering, Tuzla, Bosnia and
Herzegovina
Željko Kamberović, Faculty of Technology and Metallurgy, Belgrade, Serbia
Dejan Marković, Faculty of Dentistry, Belgrade, Serbia
Slavoljub Živković, Faculty of Dentistry, Belgrade, Serbia
Nikola Bajić, Institute for Chemical Power Sources, Belgrade, Serbia
Nenad Radić, Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia
Duško Borka, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Dušan Milivojević, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Anka Trajkovska Petkoska, University St. Kliment Ohridski, Bitola, R. Macedonia
Organizing Committee
Goran Lazić, LAFARGE BFC d.o.o., Beočin, Serbia
Vukoman Jokanović, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Snežana Pašalić, Ministry of Education, Science and Technological Development of the
Republic of Serbia
Branko Nikolić, Engineering Academy of Serbia, Belgrade, Serbia
Vesna Babić-Ivančić, Ruđer Bošković Institute, Zagreb, Croatia
Božana Čolović, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Milan Petrović, Faculty of Dentistry, Belgrade, Serbia
Svetlana Nikolić, Faculty of Technology and Metallurgy, Belgrade, Serbia
Miodrag Stević, Real S d.o.o., Belgrade, Serbia
Svetolik Baucal, Lafarge BFC d.o.o., Beočin, Serbia
Ivan Kranjčić, Zagorka, Bedekovčina, Croatia
Marko Jokanović, Tehnoimpex, Belgrade, Serbia
Nedret Kikanović, Regional Chamber of Commerce, Tuzla, Bosnia and Herzegovina
Gorica Avramović, Bomex, Belgrade, Serbia
Gordana Višnar, VIGO, Jesenice, Slovenia
Jelena Stamenkovski, Holcim (Srbija), Popovac, Serbia
Toše Dimitrievski, Vatrostalna, Skoplje, Macedonia
Momčilo Tadić, VGI-Rivir, Nikšić, Monte Negro
Dalibor Stević, Real S d.o.o., Belgrade, Serbia
Programme
General conference program
Thursday, October 23th 2014
0800-0900
Registration
0900-0930
Opening ceremony
0930-1115
Plenary lectures
1115-1135
Coffee break
1135-1340
Invited lectures
1340-1530
Lunch break
1530-1710
Invited lectures
1800-1930
Poster session
2000
Gala dinner
Friday, October 24th 2014
0900-1045
Plenary lectures
1045-1115
Coffee break
1115-1320
Invited lectures
1330-1400
Closing ceremony and awards
7 Program of lectures
Thursday, October 23th 2014
Plenary lectures: 0930-1115 (Amfiteatar I)
Chairmen: Vesna Babić-Ivančić , Vukoman Jokanović
0930-1005 Basic principles of materials design in refractory, process technology and
nanomedicine, based on nanotechnology
Vukoman Jokanović
The Vinča Institute of Nuclear Sciences, Belgrade, Serbia
1005-1040 Mechanisms of in vitro and in vivo crystallization of calcium phosphates
Vesna Babić-Ivančić
The Ruđer Bošković Institute, Zagreb, Croatia
1040-1115 Plasma - PVD technology: customized nano coatings for solar applications
Ilija Nasov
Institute of Physics, St. Cyril and Methodius University, Skopje, Macedonia
Break until 1135
Invited lectures: 1135-1340
Section: Refractory (Amphitheater I)
Chairmen: Tatjana Volkov-Husović, Mirko Gojić
1135-1200 Implementation of non-destructive methods for monitoring the degradation of
refractory materials exposed to thermal shock
Tatjana Volkov Husović
Faculty of Technology and Metallurgy, Belgrade, Serbia
1200-1225 Refractory materials used in the process of lead production
Branislav Nikolić
Engineering Academy of Serbia
1225-1250 The mineral raw materials and methods of their preparation for the use in the
refractory and process industry
Ljubiša Andrić
Institute for Technology of Nuclear and Other Mineral Raw Materials, Belgrade,
Serbia
8 1250-1315 Refractory and ceramic resources of Bosnia and Herzegovina
Amir Baraković
Faculty of Mining, Geology and Civil Engineering, Tuzla, Bosnia and
Herzegovina
1315-1340 Refractory in cement industry
Goran Lazić
Lafarge BFC, Beočin, Serbia
Section: Process industry (Hall II)
Chairmen: Željko Kamberović, Anka Trajkovska Petkoska
1145-1210 Copper, nickel and alumina based nanocomposites: different architectures
and applications
Željko Kamberović
Faculty of Technology and Metallurgy, Belgrade, Serbia
1210-1235 Impact of roughness of Zn-Mn coatings on corrosive stability
Milorad Tomić
University of Eastern Sarajevo, Faculty of Technology Zvornik, Republic of Srpska
1235-1300 Polymer surface engineering by using advanced nanotechnology
Anka Trajkovska Petkoska
The St. Clement of Ohrid University of Bitola, Macedonia
Break until 1530
Invited lectures: 1530-1710
Sections: Refractory and Process industry (Amphitheater I)
Chairmen: Amir Baraković, Mira Vukčević
1530-1555 Harmonization of European regulations and standards (EN) and the national
standards (SR) in the field of refractory materials
Sanja Martinović
Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia
1555-1620 Low cement concrete: composition, properties and application
Milica Vlahović
Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia
9 1620-1645 Catalysts: from nanotechnology to the application
Nenad Radić
Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia
1645-1710
Improving the quality of new supplementary materials for arc welding
Nikola Bajić
Institute for Chemical Power Sources, Belgrade, Serbia
Section: Nanotechnology (Hall II)
Chairmen: Dušan Milivojević, Božana Čolović
1530-1555 Surface active substances in the synthesis of inorganic materials
Maja Dutour-Sikirić
The Ruđer Bošković Institute, Zagreb, Croatia
1555-1620 Biomimetic designing of carriers and controlled drug release
Božana Čolović
The Vinča Institute of Nuclear Sciences, Belgrade, Serbia
1620-1645 Carbon nanostructured materials: theoretical aspects and applications in
electronics and medicine
Duško Borka
The Vinča Institute of Nuclear Sciences, Belgrade, Serbia
1645-1710 Electron paramagnetic resonance and nanomaterials
Dušan Milivojević
The Vinča Institute of Nuclear Sciences, Belgrade, Serbia
1730-1900
Poster session
Friday, October 24th 2014
Plenary lectures: 0900-1045 (Amphitheater I)
Chairmen: Ilija Nasov, Rebeka Rudolf
0900-0935
Methods of corrosion protection of dental alloys and characterization of
coatings
Rebeka Rudolf
Faculty of Mechanical Engineering, Maribor, Slovenia
10 0935-1010 Correlation between microstructure and functional properties of memory
shape alloys
Mirko Gojić
Faculty of Metallurgy, Department for Physical metallurgy, Sisak, Croatia
1010-1045 Properties of red-mud based geopolymers as a function of raw mixture and
activator characteristics
Mira Vukčević
Faculty of Metallurgy and Technology, Podgorica, Monte Negro
Break until 1115
Invited lectures: 1115-1320
Section: Nanotechnology (Amphitheater I)
Chairmen: Dejan Marković, Slavoljub Živković
1115-1140 Biological aspects of the application of nanomaterials in tissue engineering
Dejan Marković
Faculty of Stomatology, Belgrade, Serbia
1140-1205 Bone tissue engineering in maxillofacial region
Petrović Milan,
Faculty of Stomatology, Belgrade, Serbia
1205-1230 Nanomaterials in endodontics
Živković Slavoljub
Faculty of Stomatology, Belgrade, Serbia
1230-1255 Biocompatibility and bioinductivity of materials based on calcium silicates
and hydroxyapatite
Violeta Petrović
Faculty of Stomatology, Belgrade, Serbia
1255-1320 Advanced integrated electron spectroscopy techniques for the haracterisation
of the surface of nanostructured metallic materials
Monika Jenko
Institute of Metals and Technology, Ljubljana, Slovenia
11 Abstracts
Plenary lectures
Basic principles of materials design in refractory, process technology and
nanomedicine, based on nanotechnology
Vukoman Jokanović
The Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Influence of nanotechnology on the structure and physical and mechanical properties
of various materials used in the refractory, process industry and finally nanomedicine is very
high. The initial structure of various components in such complex systems was studied in
numerous papers in which fine details of system geometry and structure were pointed.
Although most of the components belonging to the refractory materials are much larger than
the nanometer size, advanced approaches to these technologies assume full understanding of
special role of components with nanometric dimensions. The problem of adjusting the
rheological properties of various casting mixtures is one of the main problems that can be
solved on the base of nanotechnology experience, to obtain easily flowable mixtures with
high green density, and finally sintering density after their thermal treatment in situ in the case
of monolithic refractory linings. These properties are crucial from the aspect of material
functionality, its corrosion resistance to the influence of various corrosion media and erosion,
and abrasion properties. All this indicates that nanotechnology is one of the most important
factors in design of such materials.
The similar conclusions can be drawn for any kind of material, ceramic or metal,
because the design of micro-phases between grains of its matrix is the most important for
behavior of the material in practice. Various processes as quenching should be conducted to
enable development of these micro-phases of desired design which is the most important for
functions of corresponding materials. Synthesis of very active calcium silicate phases using
colloid technology combined with the technology of self propagating combustion waves, in
our investigations, significantly improved the setting rate of these components of dental
cements, while in the case of tetra calcium phosphate, whisker phase obtained by inverse
micelle method, the material showed unusual high mechanical properties. Special attention
was dedicated to materials which can be used in tissue engineering, like hydroxyapatite, from
the aspect of particle size and shape of the initial hydroxyapatite powder, obtained by various
technologies. In every case the obtained powder was specific from the aspect of its particles
shape and specially diameter: length ratio. The powder synthesis was only the first step in
obtaining the scaffold, using different techniques. The aim was to obtain the structure with
very pronounced geometrical design which includes macro level, micro level and finally nano
level, very important for cell adhesion and attachment of filopodia during cell adhesion and
free proliferation of cells in all directions.
14 The production of starting components in all of these cases includes various
nanotechnology techniques. It can be concluded that nanotechnology enables the creation of
materials which have great potential for practical application in many areas.
Mechanisms of in vitro and in vivo crystallization of calcium phosphates
Vesna Babić-Ivančić
The Ruđer Bošković Institute, Zagreb, Croatia
Calcium phosphates (CaP) continue to attract considerable research interest due to
their role not only in biological (bones, teeth) and pathological (urinary and/or kidney stones,
carries) mineralization, but also in precipitation processes in natural and industrial waters, as
well as in production of fertilizers, ceramics, bioimplants, etc.
Formation, i.e. precipitation of calcium phosphates has been investigated both in vitro
and in vivo in various fields (chemistry, physics, medicine, biology, materials sciences). The
results obtained in in vitro investigations of CaP formation under different conditions
contributed to our understanding of mechanisms of their formation in vivo, and vice versa. As
formed calcium phosphates can be of different composition, crystallinity and morphology, in
recent years this knowledge is used in preparation of novel materials for specific applications,
like hard tissue engineering and etc.
15 PVD plasma technology and design of nanocoatings for solar thermal
absorbers
1
2
Ilija Nasov , Anka Trajkovska Petkoska
1
PLASMA – Center for plasma technologies, Skopje, Macedonia
2
University Sv.Kltment Ohridski, Bitola, Macedonia
Solar thermal collectors are mainly used for water and space heating. They capture
incident solar radiation, convert it to usable thermal energy, and transfer the energy into a heat
transfer fluid. All of this should be accomplished economically with minimum energy loss.
One of the most important components of the solar thermal collector is the solar absorber. To
be effective, the absorber should exhibit wavelength selectivity, i.e. have maximum solar
absorbance, minimum solar reflectance and thermal infrared emittance. A high solar
absorbance is needed to collect as much of the incident solar radiation as possible and a low
thermal infrared emittance is needed to minimize radiant energy losses. A lightweight
materials (copper or aluminium) having a high thermal conductivity is needed to transfer the
absorbed energy from surface to the fluid which has to be heated.
Spectral selective coatings are composed of islands of metal embedded in a threedimensional matrix of dielectric. Recent researches of authors are on mixtures of titanium
nitride and titanium oxide that has yielded spectral selective coatings with a solar absorbance
of α > 0.95 and an emittance, ε < 0.55. In most cases, they are TiNxOy coatings that are
manufactured by Physical Vapour Deposition process – combination of magnetron sputtering
and cathodic arc evaporation deposition;
TiNxOy film possesses excellent absorbance towards visible light, in which most of
solar energy lies, and good transmittance for the infrared region. This new “blue” coating,
based on Titanium, marked a significant increase in performance and represented one of the
first environmentally friendly alternative to the so far commonly used “Black-Chrome”- and
“Black-Nickel”- coatings.
In this work, the TiNxOy coating is deposited by magnetron sputtering and cathodic arc
evaporation deposition process in Ar/N2/O2 environment onto aluminium, copper and glass
substrates.
Finally, authors present some new types of coatings on different substrates as glass,
metals and polymers, two and three dimensional absorbers for solar thermal collectors.
16 Methods of corrosion protection of dental alloys and characterization of
coatings
Rebeka Rudolf1,2
1
University of Maribor, Faculty of Mechanical Engineering, Slovenia
2
Zlatarna Celje d.d. Slovenia
In this lecture a compressive overview will be presented of the typical composition,
mechanical and physical properties of two group dental alloys (basic and noble) in connection
with their corrosion resistance. Namely, formatted corrosion products of dental alloys tend to
seal the marginal gap and inhibit the entering of oral fluid and bacteria. According to this, it is
known that in most cases corrosion of the dental restorations and prostheses in the oral
environment is undesirable. In this manner it could be concluded that no dental device
(including restorative materials) is absolutely safe for the human organism.
The first group of dental alloys represents austenitic (316) and, rarely martensitic
(440) stainless steels alloys which have a variety of uses in dentistry. A common example of
corrosion of these dental alloys is rusting of iron caused by a complex chemical reaction
which is the final result in the formatting of the oxide Fe2O3×H2O. This oxide is porous,
weaker and more brittle than the metal from which is formed. One method to prevent such
types of corrosion is to alloy these materials with chromium, Nickel and Molybdenum to form
stainless steel. A second one is to perform treatments of the upper surfaces with different
coatings.
The second groups of alloys represent noble and high noble, which are usually stable
chemically and they do not develop significant corrosion; the major components of these
alloys are gold, palladium, and platinum. However, we must take into consideration the fact
that in this metals group silver is not considered as noble by dental standards since it will
react with tissue fluid, air and sulphur to form silver sulphide, a dark discoloration product.
Because silver is still used widely for the production of noble dental alloys as one of main
metals it is clear that problems with corrosion do still exist. For these purposes different
techniques of electro-depositions of the noble metals on the upper surface for such alloys are
used. One of them will be presented as successful praxis in the firm ZlatarnaCeljed.d..
Finally, characterization techniques will be presented which enable the overview and
identification of a formatted protective layer, as well as the determination of chemical
compositions.
17 Correlation of microstructure and functional properties of shape memory
alloys
Mirko Gojić1, Borut Kosec2, Stjepan Kožuh1
1
University of Zagreb, Faculty of Metallurgy Sisak, Sisak, Croatia
2
University of Ljubljana, Faculty of Natural Science and Engineering, Ljubljana, Slovenia
Shape memory alloys (SMAs) belong to a group of new functional metallic materials.
They are used in different fields: medicine, electrical and electronic industry, machine
industry etc. Shape memory effect is a remembrance of previously deformed shape of the
material, and in physical sense is a consequence of martensitic transformation in structure of a
homogeneous substance. Necessary condition for obtaining the shape memory is the presence
of the reversible phase transformation of austenite (high-temperature phase) in martensite.
This transformation is obtained by mechanical (deformation) or thermal methods (heating and
cooling).
Numerous alloys show shape memory effect. In this paper, an overview of the most
important three groups of alloys: Ni-Ti alloy (nitinol), Cu-alloy (Cu-Zn-Al, Cu-Al-Ni, etc.)
and iron based alloys (Fe-Pt, Fe-Mn-Si, etc.) will be presented. Besides nitinol, copper-based
alloys (CuZnAl, CuAlNi) have the highest application, which are much cheaper and relatively
easy to produce, and they are used as sensor, actuator, etc. Also, production methods of these
alloys such as “melt-spinner” technique (rapid solidification), production of alloys by
conventional and continuous casting, etc. will be presented. Besides the development trend
and characterization of these alloys, a part of our own research, obtained on nitinol and
copper based alloys, particularly from the standpoint of their production (casting), heat
treatment, microstructure and functional properties (hardness, corrosion resistance, etc.), will
be presented in this work.
18 Properties of Red-Mud based geopolymers as a function of Raw Mixture
and Activator characteristics
M. Vukčević, M. Krgović, I. Bošković
Faculty of Metallurgy and Technology, Univeristy of Montenegro, Podgorica, Montenegro
A wide spectrum of by-products enriched with the alumosilicates (ashes, slags,
construction remainings, red mud) can be used for the synthesis of geopolymers. Red mud, as
the by-product in aluminum industry can be activated by a highly concentrated alkaline
solution (sodium hydroxide and sodium-silicate) in the presence of silicon binder. This study
presents the influence of relevant parameters as the content of initial mixture and
characteristics of alkaline activator and different types of binder, on performances of
geopolymers with the aim to obtain satisfactory mechanical characteristics. The level of
characteristics of these materials shows all the advantages of these constructive materials in
respect to portland cement. The most convenient combination of the parameters can be
defined with the aim to enable the use of red mud as the precursor in geopolymers production.
19 Invited lectures
Refractory
Implementation of non-destructive methods for monitoring the degradation
of refractory materials exposed to thermal shock
Tatjana Volkov Husović
Univeristy of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
The purpose of this study was to investigate possibilities of using non destructive
testing methods for additional thermal shock monitoring of refractory castable. Samples based
on low cement high alumina castable sintered at 1300 °C with a dwell time of 3 hours were
used in this paper. Thermal stability of refractory samples was tested using standard
laboratory procedure of water quench test (ICS 81.080 SRPS B.D8.308 former JUS B. D8.
306). Program for image analysis Image Pro Plus was applied for monitoring destruction at
the surface of the sample before and during testing. Ultrasonic pulse velocity testing (UPVT)
was applied to measure ultrasonic velocities before and during the testing with the aim of
monitoring the changes inside the bulk. Obtained results were used for analysis of samples
degradation level before and during the testing. Based on the obtained results, models for
strength degradation of the samples during the thermal shock were proposed. Proposed
models were compared with the experimental values of compressive strength degradation
during the thermal shock. Strength degradation that defining life time of the samples was
obtained based on the analysis of the results for monitoring sample behavior due to rapid
temperature change.
21 Refractory materials used in the process of lead production
Branislav Nikolić1, Vesna Vujačić2
1
Engineering Academy of Serbia, Belgrade, Serbia
2
Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia
About 90% of the total lead is produced by pyrometallurgical processing of flotation
lead-sulphide concentrates (PbS) and waste lead accumulators (aku-waste). By roasting,
sulfides convert into oxides (PbO) which are processed in blast furnace at about 1200 ° C to
obtain the raw lead. During roasting, sulfur from the concentrate releases as SO2 which is
conducted into the plant for the production of sulfuric acid, and in this technological line
sulphureous-acid refractory materials are used.
Raw lead contains many useful metals (Cu, Sb, Ag, Bi, Au) which are separated from
the lead by refinery and are valorized into commercial products by specific processes. In
kettle furnaces for refining, standard refractory materials for operating temperatures up to 850
° C are used.
Bismuth is produced in chlorine process, so walls of settling chamber for process
gases (up to 600 ° C) and the chimney should be resistant to chlorine and chlorides.
Batches of reverberatory furnaces for processing of copper dross, and short-drum
furnaces for processing of aku-waste and As-Sb dross have a high content of soda (NaOH,
Na2CO3), and operating temperatures are about 1100 °C.
Batches of retort and cupellation furnaces for the production of gold and silver have
high zinc content and operating temperatures of about 1100 °C.
Therefore, in certain processes i.e. in certain metallurgical furnaces, refractory
materials should be used according to the operating temperature, but also depending on the
chemical composition of the treated material.
Burner holes, casting of the material from the furnace, batching and other specific
parts of the furnace are particularly burdened, and they should be specially treated and
strengthened, which significantly contributes to the long working life of the aggregate.
22 Mineral raw materials and preparation methods for application in
refractory and process industry
Ljubiša Andrić
Institute for Technology of Nuclear and other Mineral Raw Materials,
Belgrade, Serbia
Basic request for the non-metallic mineral raw materials and components which are
applied in the manufacturing of different refractory materials is to be bearers of minerals and
oxides necessary for the formation of adequate structure of the refractory material. It should
be highlighted that these raw materials should not contain impurities which could decrease
final properties of the product and negatively affect the course of its manufacturing.
Basic raw materials and components, on whose application the manufacturing of the
refractory materials is based, in wider belong to the group of silicates, alumo-silicates, oxides
and carbonates. From the natural resources the components are: kaoline, refractory clays,
silimanite group of minerals (silimanite, andalusite, kyanite), bauxite, quartz, quartzite,
magnesite, chromite, dunite, olivinite, zircon.
Besides natural raw materials for manufacturing of various types of refractory-ceramic
materials, the materials obtained via chemical processing of natural materials or via synthesis
are used. In group of such materials are: technical alumina, synthetic magnesium-oxide,
mullite, electrically melted quartz, deposited calcium carbonate, synthetic gypsum, synthetic
wollastonite, etc.
Reserves of quality refractory clays have been significantly depleted in past years, and
if serious measurements regarding preservation of existing foundations of these raw materials
are not conducted, the Serbian refractory industry will remain without raw material basis.
Having in mind acute problem of raw material basis, the investigations planned for following
years should be conducted in rest of interesting and potential parts of Serbia.
As a part of a complex consideration of the problem of refractory clays in Serbia,
physico-chemical, mineralogical and technological researches should have a huge part in
23 finding of the adequate solutions for obtaining quality materials from the clays of lower
quality.
At the same time, technological investigations should be initiated regarding
application of adequate methods of enriching clays of lower quality in order to obtain
synthetic raw material which are fulfilling the requested quality. These researches are based
on the fact that Serbia has large quantity of non-metallic mineral raw materials for process
industry, which is going to be discussed in the paper.
Refractory and ceramic resources of Bosnia and Herzegovina
Amir Baraković
Faculty of Mining, Geology and Civil Engineering, University of Tuzla, Bosnia and
Herzegovina
Refractory and ceramic resources of Bosnia and Herzegovina are characterized by
insufficient degree of exploration and low level of technological knowledge. In the overall
potential of these resources there are significant deposits of kaolin, bentonite, ceramic and
brick clay, dolomite and limestone and quartz sand, quartzite, talc and magnesite, whose
evaluation is possible. Based on the current level of knowledge on the potential of raw
material and perspectives, it can be concluded that Bosnia and Herzegovina is abundant in
various deposits and occurrences of natural resources, classified in more ore regions within
the inner and central Dinarides. Deposits and occurrences of the mentioned resources, in
genetic terms, are related to the zone of the Cenozoic Neo-Alpine autonomous activation and
sediment-genesis in the Neogene lakes and lagoons, or to multiphase polygenetic geodynamic
movements and processes whose activity was strongest in the Oligo-Miocene with calming in
the Pliocene and the Quaternary.
A multiple application of refractory and ceramic raw materials in the process industry
is possible, as a crude or refined ore whose composition is adjusted by different recipes and
demands of the industry. The quality and application of these materials in various industries
determine the chemical and mineralogical composition and technological parameters of
homogeneity in the final product. The main qualitative parameters of the listed refractory and
ceramic raw materials of Bosnia and Herzegovina are shown in this work.
24 Refractory in cement industry
Goran Lazić
Lafarge, Beočin, Serbia
The concept of refractory in its original sense, as well as refractory in the industry, is
very broad term. Consequently, each segment within the global notion has its own similarities
and particularities. The common denominator in every aspect of refractory is the need of
opposition to high temperature, abrasive reactants, thermochemical processes between
reactants and also between the reactants, technological fuel and refractory material etc.
Number of similarities is long. Of course, there are differences. Some of them are
outstanding, some are small-scale.
Mutual similarities give the space to provide universality, and thus simplify the work
with all its benefits. Mutual differences give the space to creativity, scientific research,
learning and improvement, both in technical and technological terms, and of course, to the
safety of work. A specific review of refractory in cement industry will be given in this work.
25 Harmonization of European regulations and standards (EN) and the
national standards (SR) in the field of refractory materials
Sanja Martinović
Institute of Chemistry, Technology and Metallurgy, University of Belgrade
Technical Committee for standardization of Serbia, KS B033 - Refractory materials,
which is operating withinin the Institute for standardization of Serbia has the task to prepare
the standards in the field of raw materials and products of the refractory materials industry
with monitoring the work of Technical Committees: CEN/TC 187-European Committe for
Standardization (CEN): Refractorory products and materials and ISO/TC 33-International
Organisation for Standardization (ISO): Refrectoriess. Harmonization of Serbian standards
with European ones are based on the adoption of European standars as national and especially
European standards that are directly related to implementation of the New Approach
Directives. In addition, by adopting the European standards as Serbian, all national standards
for the same items of standardization that are inconsistent with them, must be withdrawn. This
presentation would give the basic information related to the published standards in the fields
of Refractory materials, primarily referring to the European standards. Also, the Committee’s
work program which is adopted by the Expert Counsil of the ISS will be shown. The
Committee has the plan to adopt the national standards related to the environmental
management in the field of refractory materials. This presentation will show specifically
standard for shaped refractory products - sampling and acceptance testing on admission of the
samples together with the statistical assessment (ISO 5022).
26 Low cement concrete: composition, properties and application
Milica Vlahović
Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
Today’s low cement refractory castables are refractory concretes with the most of 5 %
calcium-aluminate cement and the content of CaO in the range of 0-1.5 % while the content
of water should be 4-6 %. Modern low cement concretes have the composition that provides a
dense packing of particles, high density and low porosity. Such composition involves the use
of fine and ultra-fine particles, additives or active deflocculants and other powders thus
preventing the agglomeration of particles and increasing the zeta potential of oxide grains in
concrete, and thereby reducing the required amount of water for the preparation of concrete.
Modern low cement concretes show superior physical properties compared to other
monolithic or shaped refractory materials of similar composition (content of Al2O3). The
improved properties include small porosity, high density, ultra high strength, resistance to
corrosion, erosion and abrasion, thermal stability and resistance to the effects of slag,
excellent resistance to mechanical and thermal spalling. Development of low and ultra-low
refractory concretes significantly increases the scope of application, even in cases where the
only solution was lining of the refractory bricks. Advantage in comparison with the shaped
refractory products is primarily economic (lower cost of production and application), but also
they can be simply applied in case of complex shapes and difficult to reach areas. Nowadays,
applications of low cement concretes are numerous in almost all areas of industry: metal (iron
and steel), cement, chemical, petrochemical, nuclear, in hydrocarbon waste incinerators,
power plants, and etc. It should be emphasized that low cement concretes can be sucessfully
used for repairing the damaged refractory lining.
27 Process industry
Coopper, nickel and alumina based nanocomposites, different architectures
and applications
Marija Korać1, Zoran Anđić2, Željko Kamberović1
1
Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
2
Innovation Center of the Faculty of Chemistry, Belgrade, Serbia
Considering that nanostructural materials are expected to have special physical and
mechanical properties, in the recent years the examinations of synthesis and characterization
of the nanocomposite system attracts even greater scientific interest. This paper presents
production of sintered contacts materials produced from nanocomposite powders obtained by
combination of thermochemical synthesis of Cu-Al2O3 powder and mechanical alloying of
atomized copper powder with previously synthesized Cu-Al2O3 powder. Produced powders
were characterized by X-ray diffraction and Analytical Electron Microscopy. Characterization
of sintered samples included Scanning Electron Microscopy (SEM), Energy Dispersive
Spectrometry (EDS), measurement of hardness and specific electrical conductivity. By
thermochemical method of Cu-Al2O3 nanocomposite synthesis, i.e. deposition from aqueous
solutions, in combination with mechanical alloying, significant effects of reinforcement were
achieved as a result of homogenous distribution of alumina in the nanocomposite system.
In combination with conventional methods, thermochemical process of nanocomposite
powders synthesis could be successfully applied for synthesis of new nanocomposite
catalysts, which are characterized by a high degree of dispersion of the catalytically active
component, respectively the catalyst with high activity and selectivity. The high degree of
dispersion is the result of uniform distribution of the catalytically active component into
alumina suspension, realized during the thermochemical treatment in the synthesis of
nanocomposite catalysts. In accordance with this, the paper shows the synthesis of Ni/Al2O3
and Ni-Pd/Al2O3 nanocomposite catalysts with homogeneously dispersed Ni particles, as
catalytically active component, and Pd, as activity modifier, supported on ceramic Al2O3
based foam. Namely, the previous synthesized monolith was soaked in a mixed alumina
suspension with NiCl2, PdCl2 and appropriate organic additives in order to obtain
nanocomposite catalysts with homogeneous distribution of catalytically active components.
Characterization of obtained Al2O3 foam, as the active catalytic components primary carrier,
and synthesized nanocomposite catalysts included SEM, EDS, gas permeability and
mechanical properties.
Synthesis of nanocomposite materials with homogeneous distribution of particles on
the nanometer level may lead to formation of new materials with improved or even
unexpected properties.
28 Impact of roughness of Zn-Mn coatings on corrosive stability
Milorad V. Tomić1, Milan G. Riđošić1, Miomir G. Pavlović1, Miroslav Jokić1, Jelena Bajat2
1
University of Eastern Sarajevo, Faculty of Technology Zvornik, Republic of Srpska
2
University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
This paper involves electrochemical deposition of Zn-Mn coatings from four solution,
we measured their roughness and corrosion stability. We used cathodes made of steel of
unknown composition that were licensed under the chemical preparation before the
electrochemical deposition of dual-Zn-Mn coatings, and we also used the anode of zinc,
purity of 99.99%. Dual Zn-Mn coatings were electrodeposited for 15 minutes from all of the
solutions at a current density of 1 A/dm2, 2 A/dm2 and 4 A/dm2. All experiments were carried
out in galvanostatic (at constant current) in an electrochemical cell, volume of 500 cm3 and at
room temperature.
The roughness of electrochemically deposited Zn-Mn coatings was measured by a
device TR200 and corrosion stability of deposited coatings by determining the
electrochemical impedance spectroscopy (EIS). The results show that the coatings with the
smallest roughness are coatings deposited at a current density of 2 A/dm2 from all of the
solutions. The exception is the solution 3 with the relation [Mn2 +]:[Zn2 +]=1:2 where the
roughness is at the lowest level in comparison to all solutions, ranging from 0.71 to 0.875 µm,
and the roughness is lowest at the current density of 4 A/dm2 and is 0.71 µm. Based on
electrochemical measurements, the corrosive most stable Zn-Mn coating is deposited at a
current density of 2 A/dm2 from all the solutions and at the current density of 4 A/dm2 from
solution 3 with a ratio of [Mn2+]:[Zn2+]=1:2. This suggests that the corrosion stability is
directly related to the roughness and compactness of Zn-Mn coatings. When it comes to
corrosion, the most stable coatings are those with the lowest roughness.
29 Shaping of polymeric material by use of soft lithography
Anka Trajkovska Petkoska
University St. Kliment Ohridski, Bitola, R. Macedonia
Soft lithography as a technique has been used for replicating structures with
micrometer or nano-dimensions with an elastomeric mold or stamp. In this study, soft
lithography technique has been used for manufacture regular forms of polymer cholesteric
liquid crystal material.
Liquid crystals (LCs) represent a special condensed matter phase, which belongs
between the disordered isotropic liquids and the well-ordered solid crystals. They possess the
fluidity of a liquid phase, and at the same time have a certain degree of the orientational
and/or positional order like in a crystal lattice. LC materials show pronounced anisotropic
(optical, electrical, magnetic, and mechanical) properties due to their rod-like or disk-like
nature of their molecules. Cholesteric liquid crystals (CLC) are materials, which exhibit
unique optical properties, such as selective reflection and circular polarization due to their
helical structure. With proper molecular design, polymeric CLCs with varying pitch lengths
that reflect color from deep UV- to far IR- region can be made. Polymer cholesteric liquid
crystals (PCLCs) posses fixed selective reflection color. The long-chain macromolecular
nature of PCLC materials may result in glass-formation, processing into films, good
mechanical and thermal stability. Also, PCLC could be made into shaped micro-particulate
forms by use of soft lithography. It is an inexpensive technique that uses a flexible patterned
elastomeric mold, polydimethylsiloxane (PDMS) mold. Patterning of the PDMS mold
happens after curing of PDMS material over patterned silicon wafer that serves as a template.
Different shaped polymeric microparticles have been produced in this way like,
rectangular, square, oval shapes etc. Shaped PCLC microparticles have been characterized by
different techniques viz polarized optical microscopy, scanning electron microscopy, white
light interferometry and other techniques. PCLC films and microparticles could find multiple
applications such as: notch filters, reflectors, polarizers, sensor applications. Among many
potential applications, the most attractive application of regularly-shaped PCLC
microparticles is as the low-cost alternative to the existing liquid crystal displays, and
particularly, the particle display technologies, due to their multi-color availability and low
power consumption.
30 Catalysts: from nanotechnology to the application
Nenad Radić
IChTM-Department of Catalysis and Chemical Engineering, University of Belgrade,
Belgrade, Serbia
In recent general usage, nanotechnology is any technology related to features of
nanometer scale: thin films, fine particles, chemical synthesis, advanced microlithography,
and so forth. A technology based on the ability to build structures to complex, atomic
specifications by means of mechano-synthesis; this can be termed molecular nanotechnology.
Today's nanotechnology harnesses current progress in chemistry, physics, materials science,
and biotechnology to create novel materials that have unique properties because their
structures are determined on the nanometer scale.
Heterogeneous catalytic chemists have always known that size matters. Since catalysis
is a surface effect, and active surface is a function of particle size, it is obvious that particle
size is an important variable. One of the main objectives of catalysis research is to design and
tune activity and selectivity of catalysts by controlling their structural properties at the atomic
level. In this article the current understanding of the active catalytic site and the reaction
mechanism is reviewed. The recent progress with respect to volatile organic compounds
oxidation on Pt/Al2O3 catalysts with different platinum mean crystallite size, small and large,
is summarized. The effects of the addition of manganese on the performance of small and
large Pt crystallites are also reported.
Another important aspect is the way in which catalyst materials are implemented into
catalytic reactors. Many catalytic devices used in industrial catalysis are based on monolithic
supports in which catalytic reactions occur in channels, porous walls and other confined
cavities for which coating of catalyst thin films is required. Thin oxide films as catalysts and
catalyst supports are of great importance to control the functional characteristics and, thus
their intrinsic catalytic properties. Several challenges can be mentioned in relation to the
development of these catalyst thin films in terms of thickness, surface area, control of porosity
and catalyst accessibility. Thin oxide films can also take advantage of the new generation of
microporous and mesoporous solid materials for the preparation of supported catalyst layers
able to exhibit high surface area and hierarchic porosity. Spray pyrolysis is very simple and
relatively cheap processing method to deposit thin films or coatings on different substrates.
Also, this method offers great versatility due to the large number of adjustable process
parameters, such as: spray geometry, substrate temperature, atomization technique,
composition and concentration of precursor, liquid and gas flow rates. Thin films deposition,
current status and progress in the field of spray pyrolysis will be discussed in this review. The
influence of process parameters of spray pyrolysis on film structure and properties of various
oxide films will be illustrated with some examples.
31 Improving quality of new filler for arc welding
Nikola Bajić
Research and Development Center, IHIS Techno-experts d.o.o., Belgrade, Serbia
This paper provides an overview and an analysis of the results achieved in the
development and production of new fillers with enhanced additional features of the shape and
type of flux-cored wires and special electrodes intended for arc welding.
Particular attention is paid to the development of new flux-cored wires based on
domestic raw materials with improved quality compared to conventional cored wires.
Development and organization of production of new cored wires is followed by changes in
the shape of the cross-section and composition of the active core. The thickness of the narrow
steel strip used for making a new flux-cored wire was increased multi fold compared to the
strip used for producing classical cored wire. For mastering production of new cored wires an
experimental technological line for the calibration of narrow steel strip and formation of fluxcored wires was set up. The produced new quality of flux-cored wires, designed for the MAG
and submerged arc welding process, in the course of experimental welding showed
satisfactory operational welding features and the required quality of the welded joint as
evidenced by the obtained test results.
Development work on improving the quality of the coated electrodes for welding and
surfacing is based on the use of flux-cored wire, instead of solid wire, for creating the core of
the coated electrodes and represents continuity in the development of flux-cored wires with a
higher degree of processing. Mastering production of a special coated electrode with a core of
flux-cored wire was performed on an experimental line for coating, and then experimental
welding and testing of welded joints was performed. The results obtained indicate the
feasibility of continuing the research and development work on the development of new
metallurgical quality of special coated electrodes.
32 Nanotechnology
Surface active agents in the synthesis of inorganic materials
Maja Dutour Sikirić
Ruđer Bošković Institute, Division of Physical Chemistry, Zagreb, Croatia
Surface active agents (shorten surfactants) are organic compounds containing in one
molecule both lyophobic (hydrophobic) and lyophilic (hydrophilic) parts. Due to such
amphiphilic structure surfactants exhibit specific properties in solutions (as well as in solid
state). When present at low concentrations in solutions they adsorb at all available interfaces
(liquid/gas, liquid /liquid, liquid /solid,) and as a consequence dramatically change their free
energy. At higher concentrations, above so called critical micellization concentration, when
all the interfaces are occupied, surfactants self-assemble in the bulk in various aggregates:
micelles, vesicles and liquid crystals.
Surfactants versatile phase behavior and ability to form different structures, with sizes
from nano to micro-scale, is a reason why they are widely used in various applications and
industrial processes, ranging from classical to modern technologies. Although surfactants
have been used in the synthesis of inorganic materials for a number of years, either as soft
templates or in the surfactant mediated synthesis, it is their role in the synthesis of nanomaterials which renewed interest in applying novel surfactants in the synthesis of inorganic
materials.
33 Biomimetic designing of carriers and controlled drug release
Božana Čolović, Vukoman Jokanović
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
The main problems which scientists and doctors, working in the field of bone tissue
engineering, are dealing with are related to processes of osteointegration, implantation and the
inflammation at the implantation site.
The problems of biocompatibility and osteointegration of materials used as implants in
bone tissue engineering may be solved by the formation of bioactive coatings of calcium
hydroxyapatite (CHA) on their surface using biomimetic method. This method enables
formation of CHA with similar structural and morphological properties of a natural bone. It is
based on the use of the solutions of similar ionic composition as human plasma - simulated
body fluids, providing similar conditions of CHA nucleation as in biological systems. Two
potential types of implants, metal and ceramic, were used in this study. Prior to biomimetic
treatment, the metal surface (stainless steel) was coated with the thin silica film, with OH
groups that act as active centers of apatite nucleation. Ceramic substrate- porous CHA
scaffold was treated in biomimetic medium in order to improve nanotopology of its inner
walls, optimal for growth and activation of bone tissue cells. It was previously functionalized
with polymers (PLGA, cellulose and alginate) in order to achieve its additional nanodesigning
and increase its surface activity. The phase analysis of the phases formed in the biomimetic
medium, confirmed that CHA was formed on the surface of all samples. Also, bioacceptability of these materials was investigated in vitro and in vivo and very good results
were obtained.
The problem of frequent inflammation occurring after implantation, as well as the
problem of local treatment of bone tissue diseases, may be solved using controlled drug
delivery to the affected area. The main issue is how to develop an implant material that will
have required osteoinductive and osteoconductive properties and also act as the local
regulator of the release of biologically active molecules at the interface of living tissue and
the implant. CHA, as the one of the mostly used materials in bone tissue engineering, was
used in this study as a model system to investigate the release kinetics of antibiotics used for
healing of bone tissue infections. Antibiotics were encapsulated in two different systems: in
the polymer incorporated in CHA scaffold and tablets obtained by compression of CHA
powder. Besides CHA carriers, carrier for controlled drug delivery based on SiO2 was also
created, using the spray drying method that allows obtaining the SiO2 particles of complex
structural design with simultaneous drug immobilization on these particles. The release rate of
antibiotics from these systems was measured and it was concluded that suitably designed
porous carriers can sustain a drug long enough to control the process of local inflammation.
34 Carbon nanostructured materials: theoretical aspects and applications in
electronics and medicine
Duško Borka
Vinča Institute of Nuclear Sciences, Atomic Physics Laboratory, University of Belgrade,
Belgrade, Serbia
Carbon nanostructured materials have attracted great research interest for their
potential applications in electronics, energy, materials, biomedical areas and in next
generation of electronic devices. In this paper we will focus on interaction of carbon
nanostructured materials with charged particle beams, in particular charged particle
interaction with carbon nanotubes and graphene surfaces.
The theoretical analysis has shown that the angular distribution of transmitted ions
through carbon nanotube contains the information on the transverse lattice structure of the
nanotube. The flux redistribution can be manipulated within carbon nanotubes by varying two
parameters, the incident ion angle and the initial ion energy. The cross section of the ion beam
within the nanotube can be very small; the spatial distribution contains a large, narrow central
maximum. We presented here the angular and spatial distributions of transmitted charged
particles through carbon nanotubes. Also, we discuss the problems of guiding of charged
particle beams by nanotubes and possible applications for creating nanosized charged particle
beams to be used in materials science, biology and medicine.
Well understanding of the electronic structure of graphene is a necessary first step for
the design of nanoelectronics, chemical/bio-sensors, electrocatalysts, and nanoplasmonics.
That is why investigations of interaction with particle in the context of probing plasmon
excitations in graphene by using electron energy loss spectroscopy (EELS) are of great
importance. It can be used like a novel tool for changing and controlling the electronic
properties of carbon nano-materials. We shall present here our studying that include
interactions of graphene with external charges that move at high speeds by using a dielectric
function for graphene with a two-fluid hydrodynamic model and at low speeds by using a
dielectric function for graphene within the random phase approximation (RPA).
35 Electron paramagnetic resonance and nanomaterials
Dušan Milivojević
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
EPR spectroscopy is a method that can be applied to samples that contain unpaired
electrons. There is wide range of application of this method which includes research in the
field of life sciences (nitric oxide and reactive oxygen species), bioinorganic and inorganic
chemistry (transitional metal elements in compounds and in living tissue), petrochemistry,
dosimetry, environmental chemistry, pharmaceutical industry, biophysics, food industry and
whole range of applications in solid state physics and material science, like research of
magnetic properties of materials, free radicals and defects. Most of those applications are well
established and some are routinely used.
For nanomaterials, a number of physical (mechanical, electrical, optical, catalytic, etc.)
properties change when the size of the system decreases compared to macroscopic systems.
Quantum effects can become significant when the nanometer size range is reached, typically
at size of 100 nanometers or less. The surface area to volume ratio increases altering
properties of materials.
EPR turn out to be valuable method in nanoscience research and we witness
innovative ideas of application. Author reports some applications of EPR in nanomaterials
research through examples from his practice, like carbon based nanomaterials, II-VI
semiconductor nanoparticles, silver nanoparticles etc. EPR is used to characterize the
environment of the unpaired electron, to analyze reactive oxygen species produced by
nanoparticles or to follow chemical transformation.
36 Biological aspects of application of nanomaterials in tissue engineering
Dejan Marković1, Ivana Karadžić2, Vukoman Jokanović3, Vesna Vučić2
1
Department of Paediatric and Preventive Dentistry, Faculty of Dentistry, University of
Belgrade, Belgrade, Serbia
2
Centre of Research Excellence in Nutrition and Metabolism, Institute for Medical Research,
University of Belgrade, Belgrade, Serbia
3
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Stem cells and scaffolds have an essential role in the production of new tissue by
tissue engineering. Cellular component is necessary for generation and establishment of
extracellular matrix in the new tissue, while scaffold provides mechanical stability and
foundation of a new three-dimensional tissue organization. All dental pulp stem cells have
characteristics needed for successful therapeutic applications: isolation is simple and efficient,
they have multipotent potential, and can be successfully stored long-term by cryopreservation.
Interaction with biomaterials used as matrixes induces intense proliferation of these cells.
They can differentiate into odontoblasts, osteoblasts, chondrocytes, adipocytes, neurons, and
other cells. Besides cells, the selection of a suitable scaffold material is crucial for bone tissue
regeneration. The basis of tissue engineering is to induce tissue regeneration with cell
culturing onto three-dimensional matrixes.
We examined the differential capacity of dental pulp stem cells isolated from healthy
deciduous teeth with physiological root resorption (SHED) cultured onto four different
scaffold materials: porous hydroxyapatite (pHAP) and pHAP combined with three polymers:
poly lactic-co-glycolic acid, alginate and poly(ethylene vinyl acetate)/poly(ethylene vinyl
versatate). MTT assay didn’t show any significant cytotoxic effect for the tested materials, in
the tested concentrations. LDH test showed significant cell proliferation and adhesion to all
tested materials. Alizarin red is a marker of mineralization, and the presence of colored
complex surrounding the cells indicated osteoblastic differentiation of SHED and newly
deposited mineralized matrix which they produced in presence of all tested scaffolds.
However, cells cultured on polystyrene (as control) with osteogenic medium but without
scaffolds, indicated clearly lower level of differentiation. This result confirmed the
importance of scaffold in the process of differentiation. ALP activity is a biochemical marker
for osteoblastic phenotype, mineralization and differentiation. After 12 days of culturing,
significantly higher ALP activity was found in cells grown with all tested materials than with
Bio Oss which was used as control. Scanning electron microscopy showed that, after 21 days
of culture in osteogenic medium, in the presence of each material, the extracellular matrix was
dominant, covering the scaffold and the pores. In this way, all tested materials proved to be
equal, and by many parameters even better than the gold standard in bone tissue engineering
Bio Oss. All of these materials enable binding of osteoblasts and osteoblast precursors, their
growth and differentiation in vitro.
37 Bone tissue engineering in maxillofacial region
Milan Petrović
Faculty of Dentistry, Belgrade University, Serbia
The repair of large segmental bone defects due to trauma, inflammation and tumor
surgery remains a major clinical problem. Bone tissue engineering developed into the one of
the main fields of research in regenerative medicine in the last decade. It is an alternative
approach to conventional bone grafts. The main objective of this type of therapy is to repair,
regenerate and reconstruct damaged bone. Scaffolds or cell carriers are essentially in the
tissue engineering. Scaffolds have a key function concerning cellular invasion and bone
formation. Ideally, a scaffold should have the following characteristics: (i) three-dimensional
and highly porous with an interconnected pore network for cell growth and flow transport of
nutrients and metabolic waste; (ii) biocompatible and bioresorbable with a controllable
degradation (iii) suitable surface chemistry for cell attachment, proliferation, and
differentiation and (iv) suitably mechanical properties.
Nowadays, thanks to nanotechnology, we are able to make almost ideal scaffolds.
Such scaffolds in combination with stem cells and certain active substances are widely used in
many preclinical and clinical researches concerning maxillofacial region. This presentation
will present the latest achievements and goals in bone tissue engineering in maxillofacial
region.
38 Nanomaterials in endodontics
Slavoljub Živković
Department for Restorative Dentistry and Endodontics, School of Dentistry,
Belgrade, Serbia
Nanotechnology is implemented in almost all scientific fields with huge potentials and
possibilities in medicine and dentistry. It is based on molecular self-assembly and creating
new materials with nanoparticles.
In dentistry, bioactive materials based on calcium silicate and calcium phosphate
ceramics are becoming of increasingly great importance. Their physical and chemical
properties are being researched while their development and modifications are becoming one
of the goals of nanotechnology.
Hydroxyapatite is widely used in dentistry, and it also consists of nanoparticles. It has
the ability to integrate in bone structures and support bone ingrowth without dissolving (it is
bioactive). It also stimulates osteoprogenitor cells and synthesis of bone matrix.
The development of new scaffolds is also a new field of research in regenerative endodontics.
Except its mechanical and physical properties, scaffold should also stimulate differentiation of
odontoblasts and forming a dental bridge at the place of pulp chamber floor perforation.
Different nanomaterials are used in endodontics nowadays. They are used mostly in
cases when the successful outcome is not certain (direct pulp capping, apexogenesis,
apexification, pulp regeneration). Porous ceramics, polymers, organic-inorganic hybrids of
hydroxyapatite, tricalcium phosphate, bioactive glass and glass ceramics are convenient for
application in these cases because they encourage osteoblast differentiation and forming of
mineralized tissue.
The use of nanomaterials based on silicate systems in therapy of furcation perforations
or as a sealer for root canal opturation, is also an important improvement in solving complex
problems in endodontics.
39 Biocompatibility and bioinductivity of nanomaterials based on calcium
silicates and hydroxyapatite
Violeta Petrović
Department for Restorative Dentistry and Endodontics, School of Dentistry,
Belgrade, Serbia
Fast setting of the two newly synthesized endodontic nanomaterials based on calcium
silicate (CS) and hydroxyapatite (HA-CS) (10 and 15 minutes, respectively) could be a
clinical advantage compared to commercial materials with similar chemical constitution. The
purpose of the study was to evaluate in vitro cytotoxicity and in vivo biocompatibility and
bioinductivity of a new nanomaterials based on calcium silicates (CS) and hydroxyapatite.
Cytotoxicity of a tricalcium and dicalcium silicate system (CS) and a mixture of CS and
hydroxyapatite (HA-CS) was tested using the MTT assay on human lung fibroblasts MRC-5
and compared to White Mineral Trioxide Aggregate (MTA Angelus, Soluções Odontológicas,
Brazil). Eluates of set materials were tested in 100% and 50% concentrations after 24h, 7 days
and 21 days of elution. For biocompatibility and bioinductivity studies, CS and HA-CS, were
implanted in root canals of experimental animals (Oryctolagus cuniculus), after endodontic
treatment. The animals were sacrificed 28 days later, and the treated teeth with surrounding
tissue were submitted to histological processing. The degree of inflammatory cell response
and the formation of calcified tissue were determined in the specimens. CS and HA-CS
undiluted and diluted eluates showed greater cell viability then MTA at all test periods. In 21day undiluted eluates, cell viability was greater after treatment with HA-CS than with CS.
Diluted eluates of CS and HA-CS resulted in significantly greater cell viability then undiluted
eluates of the materials. In the animal model study, there was no significant difference
between the tested materials in term of intensity of the inflammatory response. In most of
samples, inflammatory reactions were scored as mild to moderate. Neoformation of a
calcified tissue was detected in all specimens for all tested materials. CS and HA-CS showed
faster formation of calcified tissue compared to MTA. Calcified tissue in HA-CS samples was
better organized compared to CS and MTA. CS and HA-CS were less cytotoxic then MTA in
vitro. In vivo, CS and HA-CS showed similar biocompatibility and better bioinductivity
compared to MTA.
40 Posters
Refractory
Improving the characteristics of low-cement refractory concrete outside the
shelf life
Goran Lazić
Lafarge, Beočin, Serbia
In practice, it often happens for various reasons, that the refractory concrete that we
have in stock is not used within its shelf life. This means that after the specified time frame,
the manufacturer is no longer liable for its features that are specified in the declaration. Then
we find ourselves in a dilemma: to use it or no to use it. If we use it, we risk its damage with
all further consequences. If we do not use it, we make a futile expense by removing it from
the stock, making damages to our professionalism and vocation of “refractory expert”. There
are ways to mitigate this negative effect, as it will be shown in this work.
42 The installation of refaractory concrete
Goran Lazić
Lafarge, Beočin, Serbia
All involved in the installation of refractory concrete were or will be in a position to
have to make an emergency (quick, easy and effective) installation of this material in an
inaccessible position of the plant. But, that is not the only demand that an investor can place
before you. In other words, the investor does not have the space to cool the plant, which
means that you will have to do an intervention from the outside. Furthermore, even if the
plant is cooled, the damage is too small or you have to mount a scaffolding twenty feet high
in order to reach the site. The cost of scaffolding can be weleveled out accordingly, but
difficulty the time required for its assembly and disassembly. These two extremes are
sufficient to create a significant dilemma in you as a contractor, in which direction to go!?
There are ways to resolve it in an efficient way, as confirmed in practice.
43 Methods of preparation of refractory fillers for the synthesis of cast coating
Marko Pavlović1, Tatjana Volkov-Husović1, Ljubiša Andrić2
1
University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
2
ITNMS, Belgrade, Serbia
For production of the castings with favorable properties, cast coatings with the
advance quality setting must be used. During the castings, the basic role of coating is creation
of an efficient refractory barrier between sandy substrate and liquid metal flow. The coating
properties required: refractorability; favorable gas permeability; easy application and adhesion
to sand mold surfaces and polymer model surfaces; easy adjustment of thickness of the
coating layer, high drying rate, without cracking or removal of the dried coating layers, were
achieved by optimization of coating composition and their production technology. The most
important components of the coating are: the refractory filler, bonding agent, means for
holding the suspension and the solvent.
As the refractory coating filler used by the various refractories (talc, corundum,
cordierite, mica, zircon, mullite, chromite) and their selection is done according to the
characteristics: relatively high melting temperature; low heat spread coefficient; it doesn’t
soak up liquid metal; it doesn’t produce gases when in contact with liquid metal. Preparation
of the fillers is performed according to procedures oF grinding and fragmentation to the grain
size 20-40 µm.
An important coating property is the sediment stability of coating suspension.
Different kinds and quantities of additives were examined (dextrin, Na3P3O3, carboxymethyl
cellulose-CMC, bentone), as well as their activation by mixing, with an aim to enable easy
additive absorption to the refractory filler particles, maintenance of the filler in a dispersed
state and prevention of the filler build up.
A bonding agent within the coating (colophonium-C20H30O2, bentonite, Bindal H),
was chosen with regard to the size and shape of the refractory filler particles in order to enable
connection of the particles and to secure good adhesion of refractory particles to the observed
surface of either the sandy mold or polymer model.
As a liquid solvent was used alcohol, as well as water. It appeared that the optimal
density of refractory coating was 2 g/cm3. In doing so, it is preferred that the refractory filler,
with particles size up to 40 µm, to be used in an amount 92-95%; bonding agent in an amount
2.3-3.5%; additives up to 1.5%, and liquid solvent used to density of suspension up to 1.8 - 2
g/cm3.
44 Production of SiC based shaped refractory materials for application up to
1450 °C – nonferrous metallurgy, ceramic bond, secondary SiC
Vladimir Vučetić1, Milorad Vučetić1, Nemanja Vučetić2
1
Real S, Belgrade, Serbia
2
University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
Purpose of this work is conquest of production of shaped product based on SiC which
would have use in nonferrous metallurgy, primarily in production of aluminum, copper, zinc
and lead, wherein is necessary refractoriness up to 1450 °C.
Detailed process mechanism of SiC forming in industrial conditions in form of large
compact crystals is not clarified, despite to efforts of various authors. Summarized, reaction
is: SiO2+3C=2SiC+2CO. According to one scheme of SiC forming process, it is being shown
in two stages: in the beginning is formed elementary Si by reaction of C and SiO2, and then,
the liquid Si or gaseous SiO react with carbon, wherein β-SiC is being formed. All this take
place at relatively low temperature (up to 1400 °C), while formation of SiC is obtained at
much higher temperature.
In ceramic mass with suitable granulometric composition, during the sintering process
is necessary to bind the basic raw material SiC directly, by secondary SiC or by ceramic bond,
e.g. by mullite.
In this work is applied a method of production of shaped SiC refractory material by
sintering in oxidizing or neutral environment, at t=1450 °C, wherein it was necessary to
enable the sintering process of SiC forming to be carried at low temperatures by adding
corresponding mineral agent and preventing of loss of possibly present Si, i.e. SiO, and by
oxidation of graphite, while the process of formation of so-called secondary SiC is performed
in micro pores of shaped SiC refractory material, and possibly presence of oxygen is being
prevented by forming of low melting glassy phase. Converting the β-SiC to α-SiC is
performed in process of exploitation or during production process. In this way, the porosity of
final product is reduced, density is increased, and finally, as result is obtained product which
is concurrent to famous world producers (Norton, Morgan).
45 Refractory
in Serbia: problems and perspectives
Dalibor Stević
Real S Ltd Belgrade, Serbia
Current problems in refractory production and consumption in Serbia have been
analyzed on the base of numerous data. It has been noticed that domestic producers of
refractory materials are in an unequal position compared to foreign companies which sell their
products on Serbian refractory market.
The main problem is the lack of the right education, responsible people who work on
high positions in companies which are consumers of refractory materials, which usually favor
foreign producers on the account of domestic producers, without any rational reason. Beside,
week network of domestic refractory producers, their insufficient mutual communication, lack
of the right individual and common strategy are also significant reasons for such situation.
During last twenty years, previously existing development centers were shut down, together
with bankrupt of large industrial centers for the production of refractory materials.
Perspectives are in education of new young experts and networking between experts
from this area, connections of various producers with their small companies, with the aim of
faster development and implementation of innovative technologies in the practice and more
efficient access to the customers of refractory materials.
46 Refractory gunning mixes – new applying possibilities
Vladimir Vučetić, Dalibor Stević, Jovanka Malešević
Real S, Belgrade, Serbia
Company Real S, in cooperation with company Albos, has developed gunning mixes
with wide application in refractory industry. The gunning mixes have advantages comparing
to other refractory shaped or monolithic products because of their possibility to apply on
unreachable places, and casts are not necessary. Particular advantage of these mixes is
possibility of application to hot surfaces, without need of turning off and cooling the thermal
unit. Also, material loss is reduced to 5-10 %, which saves time and money.
We produced semi acidic gunning mixes based on Al2O3 as holder of refractoriness
which have wide range of application in thermal power plants, cement industries, etc; also
alkali gunning mixes based on MgO as holder of refractoriness which have wide application
in ferrous metallurgy. Semi acidic gunning mixes have been successfully used for many years
in cement plants Lafarge BFC, Beočin and Holcim (Srbija), Popovac. Alkali gunning mixes
were successfully tested in steel smelter Sirmium steel, Sremska Mitrovica.
47 Reparation of foundry ladles by refractory mixes
Boro Hinić
Real S d.o.o. Belgrade, Serbia
In older foundries of gray cast iron, for ladle repair chamotte mud is still used. If mix
for ladle repair is not dried appropriately, during the casting process the melt can be
frequently boiled, influencing formation of scarp and interruption of casting process. Optimal
solution for fast repairs should be waterless refractory mixes based on tar and various organic
resins, which enables small repairs onto the surface of hot areas of refractory lining. This
solution is optimal for such application in domestic consumers of such refractory materials.
Therefore, this approach can be observed as promising for experimental investigations and
industrial testing in our foundries.
48 Deposits of boron minerals in Adriatic basin
Nebojša Videnović
Belgrade University, Faculty of Mining and Geology, Belgrade, Serbia
Deposits of boron at Piskanja, Baljevac - Serbia, are unique in this part of Europe. Due
to its quality crude ore obtained from this deposit is exported worldwide, as they are India,
Italy and Germany. Taking in mind its established reserves and very wide opportunities for
processing in more than 102 products this mineral can be observed as strategic resource of
national economy. On the base of given data in this paper, potential reserves of boron in
corresponding ore deposits are estimated about 7.500.000 tons, with average content of boron
around 36%. These reserves are probably significantly larger, due to special structure-tectonic
and geologically-mineral-genetic position of deposit, showing so a very big importance for
development our economy. For more efficient exploitation numerous questions should be
solved, previously, like conditions of exploitation, kind of investigations, maximal allowed
distances among particular investigations, distribution of deposits and ore bodies towards of
the genetic type and size, categorization and classification of reserves, etc.
Small efficiency of manufacturing caused by manual ore selection, shows that Pobrđe
deposit, particularly in the region Piskanja, can be promising for further technological
exploitation over previous usual ore treatments by the methods of magnetic and electrostatic
separation and subsequent thermal treatment at about 500 C. Finally, industrial testing is
necessary.
49 Refractory concretes
Olivera Ljubić
Elka d.o.o., Arandjelovac, Serbia
Refractory concretes are shaped or unshaped products, made on the basis of one or
more raw materials without the use of hydraulic or other binders. They consist of a large filler
and ceramic binder. Comparison of quality characteristics obtained from the same raw
materials, by the method of refractory concretes production and other known ways of shaping
indicate that this type of material has a higher apparent density, mechanical strength and
thermal stability. It binds at low temperature, which ranking them among the materials with
favorable energy balance.
The history of the development of this type of material, the principles of production,
technological line, types depending on the used raw materials, with emphasis on the
advantages and disadvantages of the technology, will be presented in this study.
50 The production refractory, fireproof, acid proof and ceramic product
Branimir Špiljak
Zagorka, Bedekovčina, Croatia
Our factory “Zagorka” was founded in Bedekovčina in 1889. The main reasons for
starting the factory were high quality clay deposits and the railroad which had been there even
in that time. The location of the factory has been in the central Zagorje in Croatia in the town
Bedekovčina from its beginnings. In 1923, in one of the Zagorka's section, started the
production of fireclay ovens and tiles for the stoves. The Zagorka has been working in the
today's form since 1995, and we produce fireproof and acid proof materials, decorative-utility
ceramics, ceramic lining for furnaces, fireplaces and tile stoves. The Zagorka has a program
of producing fireproof and acid proof products, and we make materials for heavy industry
(ironworks, foundries), boiler plants, thermal power plants, chemical and petrochemical
plants. Producing programs is constantly enriching with new products upon customers’
requests.
51 Reserves of quartz sand in the Tuzla basin and its industrial application
Rešad Husagić
Coal mines “Kreka”, Tuzla, Bosnia and Herzegovina
Quartz sand is a natural material that is widely used for the production of many
products based on silicates. In the wider area of Kreka pool long-term research was conducted
on the quantity and quality of quartz sand. Depending on the activities of individual
development programs in domain of silicate complexes, partial research was performed in
some locations. Raw potential of Kreka basin, according to the previous research, is estimated
to be about 9.6 x 109 m3 of quartz sand.
The paper presents the possibility of application of quartz sand, found as
accompanying deposits in the coal basin “Kreka” in Tuzla. Possibility of application is
determined on the basis of established properties of quartz sand, either as a raw material either
after a certain degree of refinement.
52 Natural resources of Gračanica area in B&H
Damir Baraković
GRANEX doo, Gračanica, Bosnia and Herzegovina
Refractory and ceramic resources of Gračanica were studied in this paper. In Bosnia
and Herzegovina there are significant deposits of bentonite, ceramic and brick clay, dolomite
and limestone and quartz sand, quartzite, which should be more evaluated. Gračanica area is
rich in various natural resources, belonging to the inner and central Dinarides. These
resources in genetic terms are related to the zone of Cenozoic Neo-Alpine autonomous
activating and sediment-genesis in the Neogene lakes and lagoons, or to multiphase
polygenetic geodynamic movements and processes whose activity was strongest in the
Miocene.
53 Applicability of quartz sand from the reservoir “Bukinje” near Tuzla
Hamo Isaković, Amir Baraković, Damir Baraković
Faculty of Mining, Geology and Civil Engineering, Tuzla, Bosnia and Herzegovina
Quartz sand reservoir “Bukinje” is located about 2 km west from Tuzla. It is very good
communicatively connected and could say, optimaly stationed in respect of gravitating
market. The reservoir “Bukinje” represents the part of the upper pont, ie. the immediate floor
of the first roof coal layer of crack lignite. Tectonically, the reservoir represents a small
segment of the northern flank of the anticline “Ravna Trešnja”.
From the data of granulometric study it can be concluded that the fraction of finegrained sand is dominant, with content of 78% and 23% of silty-clay fractions. The content of
SiO2 as one of the most important components of the chemical composition ranges from 8391 % while this content can be greatly increased by breeding (90-94%). The mineral
composition of sand consists of quartz and feldspar (98.5%) and heavy minerals (1.5%).
Certain adverse effects that occur during sand grinding to a fineness of cement, which are the
consequence of the content of silty-clay part of the natural sand, can be solved by previous
washing of sand.
54 Andalusite – refractory raw material: properties and application
Xiao-Yong Xiong, Aleksei Bobkov
IMERYS Refractory Minerals, Paris, France
Andalusite is an alumino – silicate mineral belonging to the sillimanite family. It is
present in the form of stick in the rocks composed mainly of quartz and micas. The andalusite
processing consists of its separation from the quartz and the micas. The andalusite stick's size
limits the maximal size of the andalusite grain. It’s very difficult to produce the big size of
pure andalusite. IMERYS has developed a complete andalusite processing technique, and
successfully produced the 8 mm size andalusite product. The chemical composition of
andalusite is bi-oxides of aluminum and silicon: Al2O3.SiO2 with a density 3.15. The
andalusite can be directly used as raw refractory material without any thermal treatment. It
will be transformed to mullite and silica glass at 1200° - 1400°C.
After mullitisation of the andalusite, the excess of SiO2 content transformed to glass is
dominant inside the mullite phase. A small part of this glass is on the surface of the mullite
crystal. At the high temperature, the glass softened or fused inside of the mullite can absorb
the volume change of the mullite with the temperature. In this way, the mullite obtained from
andalusite has the more thermal stability than the other types of mullite. This softened glass
can penetrate in the possible crack fissure of transformed mullite as a welding agent to repair
the damaged mullite during the use.
Andalusite has a higher refractoriness under load and a higher resistance to creep than
other silico-alumina materials as bauxite, chamotte etc.
The principles of andalusite application in refractory can be summarized in three points:
1) application of mullite which is reputed as the best of the materials with a high thermal
stability and a high creep resistance; the mullite based products are used specially in the
equipments submit in the high temperature of long time and in the frequent thermal choc
environment, 2) advantage of the slight expansion: after being fired the andalusite based
products remain a slight expansion (PLC at 1500°C is +1%) useful to control the fired process
of product which helps avoiding the split between the bricks, and the crack of the castable, 3)
application as bonding agent: the thermal transformation of andalusite powders to mullite can
form bonds between the mullite, the excess of SiO2 on the mullite surface can react with the
alumina powders to form a second mullite and also a bonding system which is formed at the
middle temperature range (1200°-1400°C) having very high refractoriness as mullite.
Andalusite can be applied as a product based fully on the andalusite which possesses the
same characteristics as a mullite product, or as a product with andalusite powder as matrix
and bauxite or corundum as grain which has the high thermal stability and high creep
55 resistance as mullite products, and the high abrasive resistance and high refractoriness as
bauxite and corundum products.
Nowadays, the andalusite based products are widely applied in the process of iron, steel
and aluminum production; in ceramic, cement and glass industry; in kiln furnaces, etc.
Effect of mechanochemical activation
Milan Petrov, Ljubiša Andić, Zoran Bartulović
Institute for Technology of Nuclear Mineral Raw Materials, Belgrade, Serbia
The presented results refer to the investigation of effect the mechanical-chemical
activation of flotation tailings on copper, iron and sulphur leaching degree in the sulphuricchloride solution with the addition of H2O2 as oxidant. A sample of the Bor flotation tailings
(BFT) from the old Bor flotation tailing dump consists of pyrite and tailings as the main
components, and is activated in a dry process of the vibro mill with (BFT1) and without
(BFT2) addition of NaOH as the chemical reagent. Using the dry magnetic separation in the
high-gradient magnetic separator Sala, the samples were separated into magnetic fraction,
BFT MF and BFT NMF respectively.
Leaching of various treated samples showed that the highest level of copper leaching
(98.7 wt %), was obtained for BFJ2 MF sample while the leaching degree of Fe and S was
higher in non-magnetic, up to 92.46 wt % in BFT 1 NMF sample for Fe and 80.62 wt % for S
in BFT 2 NMF sample.
56 Process industry
Application of the new lightweight aggregate based on natural pozzolanic
and waste materials in concrete production
Ognjen Rudić1, Nenad Milenković1, Vilma Ducman2, Snežana Vučetić1, Jonjaua Ranogajec1
1
University of Novi Sad, Faculty of Technology, Novi Sad, Serbia
2
Slovenian National Building and Civil Engineering Institute, Ljubljana, Slovenia
The properties of designed lightweight aggregates (LWA) obtained by the thermal
treatment of raw composition based on natural pozzolanic material, waste glass, suitable
polymer and wooden dust are presented. The production process of LWA consisted of raw
material preparation, plastic shaping - extrusion, granulation and thermal treatment. The final
temperature (T=1020oC) was chosen based on the appropriate mechanical and physical
properties of the designed LWA pellets. Properties of raw natural pozzolanic material were
examined by using DSC/TGand dilatometry, while waste glass was characterized by chemical
analysis and XRF.
The particle size distribution of the LWAs was unimodal (d ≈ 5 mm). Textural and
mechanical properties of LWA pellets were examined by water absorption, mercury
porosimetry and compressive strength. The microstructure characteristics of LWA pellets
were characterized by SEM analysis while phase composition during thermal treatment was
studied by using high temperature XRD analysis. Thermal conductivity of unbound, fired
LWA pellets was determined by measuring the amount of axially transferred heat in the
stationary state. The obtained results show that the LWA thermal conductivity (λsr=
0,702W/mK.) is suitable for the production of structural concrete blocks with improved
thermal insulating properties. Due to their high porosity and appropriate compressive strength
values, the designed LWA were used in the production of concrete blocks (one third of the
natural aggregate was replaced with designed LWA). Due to good thermal conductivity value
(λsr= 1.31 W/mK) and compressive strength (61,57MPa after 28 days of curing), the concrete
with designed LWA could be classified as a normal high strength concrete.
57 Importance of determination of silicate dust in the processing of raw
materials of mineral origin
Borislav Simendić, Vesna Petrović
High Technical School of Professional Studies, Novi Sad, Serbia
This paper is based on an analysis of the dust that are risky in the work environment,
especially those that are present in the ceramic industry, as well as a negative perception of
their impact on the health of persons exposed to it. The paper deals with the results of
measuring the concentration of dust in the processing of natural stone. The aim of this work is
dating with diseases that consequence of the presence of silicate dust in the working
environment, and the importance of prevention of the same, namely safety at work under
conditions where dust is present. It is shown that depending on the climate and working
conditions in the processing of natural stone the concentration of dust in the working
environment is changing. The greatest threats to the health of employees are climatic
conditions with the lowest moisture content. In case of sanding granite without ventilation the
maximum dust concentration of 77 mg/m3 was measured.
58 Modification of titanium substrate by alkaline and heat treatment
Bojan Jokanović1, Vukoman Jokanović2, Miroljub Vilotijević2, Rebeka Rudolf3
1
SGL Carbon, Meitingen, Germany
2
Vinča Institute of Nuclear Sciences, Belgrade University, Belgrade, Serbia
3
University of Maribor, Faculty of Mechanical Engineering,
Maribor, Slovenia
Surface modification of titanium and its alloys by formation of thin oxide layers is
often necessary to enhance their biological properties. In this study, the titanium substrate was
firstly alkali treated with NaOH, then it was subjected to the ionic exchange of Na+ with Ca2+
ions and finally it was thermally treatment at 700 °C. After treatment the substrate was
investigated by X ray diffraction, Fourier transformed infrared spectroscopy and Auger
electron spectroscopy to analyze the chemical changes and changes of Ti oxidation states, as
well as the obtained phases, along the depth of the titanium oxide coatings. The morphology
of the sample was analyzed by Secondary Electron Imaging, showing very interesting nanotopology consisting of interconnected pores and thin walls between them. The structure like
this seems to be very suitable for further deposition of hydroxyapatite and also as a promising
scaffold for cell adhesion and proliferation.
59 Hydroxyapatite coatings on titanium substrate obtained by high energy
plasma jet deposition
Miroljub Vilotijević1, Božana Čolović1, Monika Jenko2, Vukoman Jokanović1
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
2
Institute of Metals and Technology, Ljubljana, Slovenia
1
Hydroxyapatite (HA) coatings were deposited on the surface of titanium substrate by
the plasma jet method with high electric energy input. Prior to the deposition the substrate
surface was alkali etched with NaOH and then thermally treated. The XRD spectra of the
obtained coatings showed that they consisted mainly of crystalline HA and small quantities of
the amorphous HA phase. The SEM analysis showed very interesting and different
morphology of the HA coatings with specific micro-structural features desirable for
improving the coatings’ biological performances. The AES analysis performed on various
spots on the boundary of the titanium substrate and the coating showed the presence of
several oxidative layers and the implantation of Ca ions inside them due to high kinetic
energy of the plasma jet beam. Adhesive strength measurements showed very good results,
showing values greater than 50 MPa.
60 Degradation of Reactive Blue 52 dye waste water by ClO2 in the presence of
La-doped TiO2 as catalyst
Jelena Nešić1, Goran M. Roglić1, Biljana P. Dojčinović2, Milica Jović1, Predrag J. Vulić3,
Jugoslav Krstić4, Dragan D. Manojlović1
1
Faculty of Chemistry, University of Belgrade, Belgrade, Serbia, 2Institute of Chemistry,
Technology and Metallurgy, Center of Chemistry, University of Belgrade, Belgrade, Serbia
3
Laboratory of Crystallography, Faculty of Mining and Geology, University of Belgrade,
Belgrade, Serbia,
4
Institute of Chemistry, Technology & Metallurgy, Department of Catalysis & Chemical
Engineering, University of Belgrade, Belgrade, Serbia
Chlorine dioxide (ClO2) is one of the disinfectant agents used in water treatment plants
as an alternative to chlorine, since unlike the chlorine, ClO2 does not form trihalomethanes.
Also, photocatalysis with TiO2 as catalyst is very promising in the field of environmental
remediation, especially with modified, doped TiO2 which has proven to be more efficient.
Therefore, the combination of these two processes can be used and take advantage of
potential synergistic effect. Experiments were conducted to investigate the removal of
Reactive Blue 52 dye in order to assess the effectiveness of chlorine dioxide catalytic
oxidation process under sun-like radiation. The catalyst used in this process was La-doped
TiO2. La-doped TiO2 photocatalysts with different content of La (0.2, 2 and 4% (w/w)) were
synthesized by the microwave-hydrothermal method and characterized by XRD, SEM and N2
physisorption at 77 K. The photocatalyst with 2% La was found to be the most efficient with
ClO2. The operating parameters such as the ClO2 dosage and initial pH were evaluated. The
2% La-doped TiO2 catalyst with ClO2 showed higher efficiency than commercially available
TiO2 Degussa P25 under the same conditions, therefore it can be considered as good
candidate for wastewaters remediation purpose.
61 Solving a technical problem in the field of medical waste incineration
Branko Pejović, Milorad Tomić, Vladan Mićić
Faculty of Technology Zvornik, University of East Sarajevo, Republic of Srpska,
Bosnia and Herzegovina
In this paper, a case of incineration of two typical medical wastes in the furnace is
described. Maximum amounts of both wastes that can be burned at the given conditions were
determined with a large number of limitations characteristic for the observed problem. At this,
the analytical geometry method was applied, where two variables that represent the mass flow
of mentioned wastes were included. A mathematical model with six limitations in linear form
is formed on the basis of thermodynamic relations of combustion process of waste. A
presentation of method at one numerical example from practice was given, where besides
required quantities of waste, working area was determined. The solution of the problem was
obtained using lower heating temperature of waste. Obtained graphical solution was verified
by analytical method.
62 The future of biofuels
Vladan Mićić, Milovan Jotanović, Milorad Tomić, Branko Pejović, Zoran Petrović
Faculty of Technology Zvornik, University of East Sarajevo, Republic of Srpska,
Bosnia and Herzegovina
Biofuels are the future chief energy source of the world. Based on the fact that fossil
fuels are non-renewable reserves, logic dictates that fossil fuels will eventually be diminished
and no longer be mankind’s go to source of energy. Biofuels, on the other hand, will
definitely be staying for the foreseeable future and can still continue to provide the earth and
the human population with a relatively clean source of energy with several benefits such as
economic benefits of providing employment and health benefits of reduced carbon emissions,
leading to cleaner air. With increasing sophistication of technology and intense research and
development done, one can safely infer that biofuel will become more appealing and
applicable to be used on a globally commercial level. As such, biofuel is acknowledged as the
Earth’s future energy source. Until such time where a newer and cleaner source of energy is
discovered, scientists will definitely persist to research and enhance biofuels to make them
more cost-effective, while still being environmentally friendly.
63 Al2O3/TiO2 mixed oxide coatings: optimization of processing parameters
regarding photocatalytical properties
Nenad Tadić1, Nenad Radić2, Boško Grbić2, Rastko Vasilić1, Stevan Stojadinović1
1
University of Belgrade, Faculty of Physics, Belgrade, Serbia
2
University of Belgrade, Institute of Chemistry, Technology, and Metallurgy, Department of
Catalysis and Chemical Engineering, Belgrade, Serbia
Influence of processing parameters on photocatalytic properties of mixed oxide
Al2O3/TiO2 coatings is investigated. Mixed oxide semiconductors are prepared using plasma
electrolytic oxidation of aluminum in water solution of sodium silicate, with varying
concentrations of Degussa P25. Obtained oxide coatings are characterized using SEM-EDS
and XRD analyses, while their photocatalytic activity is determined by degrading methylorange at room temperature. Optimization of processing parameters identified concentration
of 2 g/L TiO2 as the most favorable for producing mixed oxide coatings with high
photocatalytic activity.
64 Life cycles of adsorbents in the process of mineral base oil treatments
Zoran Petrović1, Pero Dugić2, Stojan Simić2, Vojislav Aleksić1, Vladan Mićić1,
Mirko Petković2
1
Faculty of Technology Zvornik, University of East Sarajevo, Republic of Srpska
2
Oil refinery, Modriča, Republic of Srpska
Aluminosilicate clays have a structure and composition that allows a wide application
in various industries. Also they have relatively good adsorption characteristics, which can be
significantly improved by using a method of modification chemical structures. One of their
most important applications is the adsorption process in the treatment of mineral base oils,
edible oils, and in the process of environmental protection. In the production of mineral base
oils commercial active clays obtained by the activation of natural aluminosilicate clay by acid
are used. As result of this process there is a change in the structure, composition and their
characteristics. After refining of mineral base oil by active clay obtained refined base oil as
primary product and oil filter cake as by-product, which is categorized as hazardous waste.
There are several methods to solve the problem of obtained waste and the priority given to
those that are safe for the environment and human health. One of the acceptable ways for
solving this problem is the production of ecological briquettes from the "hazardous waste"
and the waste generated in treatment of wood (wood chips), which would be used as fuel for
households. These investigations showed that high quality and environmentally friendly
energy source for using in household can be obtained from by-product. In this paper is
presented life cycles of commercial active clay in the process of treatment mineral base oils.
The basic characteristics, composition and structure of commercial active clay used in the
treatment of mineral base oil and oil filter cake and wood chips, as well as obtained ecological
briquettes are presented. Different instrumental analytic methods (FTIR, ICP-AES, XRF), and
scanning electron microscopy with EDX were used.
65 Innovative company ALBOS and its main activity
Vukoman Jokanović
ALBOS company, Belgrade, Serbia
Program of an innovative company ALBOS is oriented to the development of
technology for various presumably refractory materials and their application in industry, with
very close collaboration with other small companies - producers of such materials in Serbia.
This form of activity is very interesting as one kind of transfer of high technology in
real industry and market, in this case refractory market, but in the other case it could be any
other product which can be implemented in any kind of processing industry. The huge
ALBOS network of professionals and specially its very high experience in various
technologies is a nice example how the science can be connected with real industrial needs.
In the case of better and more transparent market approach, this kind of cooperation
can be very fruitful for most of small enterprises and companies. This kind of strategy can be
accepted from others companies from the region, with the aim to form one strong center over
ROSOV for networking all subjects with their problems and needs.
The company ALBOS developed several products which have been applied in various
large companies, producers of steel, cement or coke.
66 Study for implementation of solar thermal systems in a
local diary production capacity
Aleksandra Jakimovska1, Anka Trajkovska Petkoska1, Ilija Nasov2
1
Faculty of Technology and Technical Sciences,
University St. Clement of Ohrid, Bitola, R. Macedonia
2
Plasma-Center for Plasma Technologies, Skopje, R. Macedonia
Solar energy as a clean, safe and endless source of energy that is available everywhere
can replace the fossil oils. Macedonia has a duty to decrease the emission of greenhouse
gasses as other countries in the region according to Kyoto Protocol. This duty should not be a
big problem for our country since that the potential of most of renewable energies is very
high.
In this study, the example of replacing a part of energy source (electricity) with RES
in a local dairy company in the region of Kichevo (Macedonia) is explained. The energy of a
daily solar irradiance in this region is ~ 4100 Wh/m2/day, (according to PVGIS - Photovoltaic
Geographical Information System) that is close to average value of the country. This is a big
advantage of this region to use the solar energy in households as well as in industrial
capacities.
Dairy industries are one of the most interesting capacities for use of renewable energy
and particularly of solar energy since that they work in most cases 7 days a week and
continuous use of hot water which is possible to be used from the solar thermal systems.
According to data available from a local capacity “Bistra”, Kichevo, authors attempt to
present the need of solar thermal system that contains 20 solar thermal collectors (or 40 m2
collector absorbance area) and they in full will satisfy the need of hot sanitary water in this
local capacity. Savings due to installation of solar system are also calculated in this study.
Briefly they can be presented as: payback period of ~ 2.4 years, decrease of CO2 emission of
208 kg/annual per 1m2 collector area; savings for electricity of ~3900 Eur/annualy, etc. This is
a big advantage to environment and makes the Earth safe and clean place for next generation.
67 Global Ispat Coke Industry d.o.o.
Dževad Šehić
RJ Koksovanje, Lukavac, Bosnia and Herzegovina
Global Ispat Coke Industry d.o.o. Lukavac (GIKIL), located in Bosnia and
Herzegovina, southeastern Europe, is the company known for its high-quality products and
services as well as long-standing customer relationships. The company has more then 1000
employees and the whole complex with its five operating industrial units covers an area of
over million square meters.
Our range of products like metallurgical coke, anhydride of maleic acid, mineral
fertilizers, power, potable water, decarbonized water and demineralized water is creating
added value for our customers in a variety of industies. GIKIL´s products are highly
appreciated across the world by their quality. These are the brands, built on relationship of
quality, service and trust that provide the motivation for further innovation and technological
excellence at GIKIL. GIKIL is the leading metallurgical coke producer in the Region and is
known for its superior quality product and long-standing customer relationships.
68 Nanotechnology
Vital pulp therapy with MTA after traumatic dental injuries
Dejan Marković 1, Ana Vuković 1, Bojana Ćetenović 2, Vukoman Jokanović3
1
Department of Pediatric and Preventive Dentistry, School of Dental Medicine, University of
Belgrade, Belgrade, Serbia
2
Department of dental Medicine, Faculty of Medical Sciences, University of Kragujevac,
Kragujevac, Serbia
3
Vinča Insitute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Complicated crown fractures represent 11.9-20.0 % of all traumatic injuries to
permanent teeth. Pulp healing after traumatic exposure is possible, but in correlation with
time interval of pulp exposure, width of exposure, stage of root development and presence of
concomitant injuries. Pulp necrosis and arrested root development may influence long term
prognosis of the injured tooth. Several materials have been used as pulp dressing in vital pulp
therapy. To date, calcium hydroxide has been widely used and recognized as material of
choice. However, in the past decades alternative material Mineral Trioxide Aggregate (MTA)
has been introduced and used due to biocompatibility and low cytotoxicity. Various clinical
and histological studies have demonstrated the superior therapeutic effects of MTA inducing
the pulp regeneration after traumatic exposures which induces irreversible pulpitis. Also it has
been confirmed that MTA enhances the proliferation of dental mesenchymal cells, but causes
no cell death on the odontoblastic differentiation of pulp cells as compared with other
materials. MTA provides an enhanced nonresorbable seal over the vital pulp. MTA has shown
high clinical and radiographie success rates as a pulp agent in immature permanent teeth after
traumatic exposures of the pulp.
69 The biocompatibility investigation of MTA using animal models
Bojana Ćetenović1, Dejan Marković2, Ana Vuković2, Vukoman Jokanović3
1
Department of Dental Medicine, Faculty of Medical Sciences, University of Kragujevac,
Kragujevac, Serbia
2
Clinic for Paediatric and Preventive Dentistry, Faculty of Dental Medicine, University of
Belgrade, Belgrade, Serbia
3
Vinča Institute for Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Biocompatibility is defined as the material’s ability to perform desired function in the
body after its application without causing unwanted response of the host tissues. The
contemporary aspect of examining materials’ biocompatibility includes three levels of
research: in vitro tests in laboratory conditions, in vivo tests on experimental animals and tests
of application. Mineral trioxide aggregate (MTA) has appeared in the use during nineties as a
material of choice for retrograde cavities, but today has a broad range of indications in
dentistry. The aim of this work was to summarize the results concerning the biocompatibility
of MTA using animal models.
A review of the literature was performed by using electronic-searching method
indexed in ScienceDirect scientific database and published from 1993 to 2013. The key words
used were: MTA, biocompatibility and animal. In this period, 211 manuscripts (40 reviews
and 171 research articles) concerning the biocompatibility of MTA using animal models were
published.
Results of numerous studies showed that subcutaneous responses to MTA ranged from
moderate to severe, but decreased over time. Results of intraosseous implementation of MTA
demonstrated relatively mild inflammation of bone tissue without necrosis, bone resorption,
and infiltration of mononuclear inflammatory and foreign body giant cells.
70 Analysis of the glass-ionomer fissure sealant adhesion to enamel- a
SEM/EDS and clinical study
Bojan Petrović1, Dejan Marković2, Tamara Perić2, Vukoman Jokanović3, Branislav Bajkin1,
Djordje Petrović1, Duška Blagojević1
1
Dental Clinic of Vojvodina, Faculty of Medicine, University of Novi Sad, Serbia
2
Department of Paediatric and Preventive Dentistry, School of Dentistry, University of
Belgrade, Serbia
3
Institute of Nuclear Sciences “Vinča”, University of Belgrade, Belgrade, Serbia
The purpose of this study was to examine morpholological characteristics of the
interface zone between glass-ionomer and the enamel surface, to evaluate the presence of the
fluoride ions at the interface zone and the enamel surface and to evaluate clinical efficacy of
glass-ionomer fissure sealant in 36 months observation period. Five intact third molars were
used in the experimental study, and six section of each tooth were examined.
SEM/EDS analysis was performed at the material in the proximity of the interfacial
zone, the interface and the enamel surface. Clinical examination comprised 60 participants
and investigated parameters included: the retention rate, margin adaptation, color match,
surface smoothness and caries occurrence. SEM analysis revealed the presence of thin
uniform layer at the interface zone of chemical bonding between the material and the enamel
surface. Morphological analysis of the interface zone between the glass-ionomer and the
enamel revealed the presence of the hybrid layer of chemical bonding with specific
morphological characteristics. The interface zone turned out to be about several micrometers
thick, with various cracks and voids present predominantly in the material structure. Interface
zone was flattened, without significant changes at the enamel surface. Enamel prisms
appeared to be intact, without material tags penetrating the enamel surface. EDS analysis
confirmed the presence and availability of fluoride ions at the interface zone and at the enamel
surface. Regarding the retention, fissure sealant exhibited rather low complete retention rate
in 3 years observation period. Partial loss of fissure sealant was the most frequent clinical
finding (47%), while complete loss of fissure sealant was noticed in 12 cases. Almost 30% of
the placed sealants exhibited satisfactory margin adaptation at the end of the observation
period. Regarding color match and surface smoothness, glass-ionomer sealant exhibited
constant characteristics throughout the investigation period. Regarding the occurrence of
caries lesions, they were noticed in two cases, during the first year of observation. Caries was
observed in two cases. Clinical investigation confirmed strong occlusal surface protection
after glass-ionomer sealant placement. SEM analysis revealed the presence of thin uniform
layer at the interface zone of chemical bonding between the material and the enamel surface.
EDS analysis confirmed the presence and availability of fluoride ions at the interface zone
and at the enamel surface. Clinical investigation confirmed strong occlusal surface protection
after glass-ionomer sealant placement.
71 Cytotoxicity of the surface of titanium oxide thin films
Marko Magić1, Dejan Marković2, Vukoman Jokanović3
1
Department of Oral Surgery, School of Dentistry, University of Belgrade, Belgrade, Serbia
2
Department of Pediatric and Preventive Dentistry, School of Dentistry,
University of Belgrade, Belgrade, Serbia
3
Institute of Nuclear Sciences “Vinča”, University of Belgrade, Belgrade, Serbia
Titanium and its alloys are widely used as implant materials in implant dentistry and
orthopedics, due to their good mechanical properties, corrosion resistance and
biocompatibility. Surface modification of titanium and its alloys, by formation of thin oxide
layers on their surface using various chemical methods is necessary to provide more suitable
surface for cell attachment than unmodified metal titanium surface. Titanium substrate, after
etching with NaOH, subsequent replacement of Na+ with Ca2+ ions, and final treatment at 600
°C was subjected to cytotoxicity testing and compared to untreated titanium substrate.
Cytotoxicity was examined on the cell line L929, using MTT, LDH and cell viability assays.
Qualitative verification of the results was performed using light microscopy, based on the
morphological characteristics of the cells and the confluence of the cell growth in the culture.
The obtained results of cytotoxicity assessment of Ti- based samples performed on L929 cell
line indicates almost complete absence, or minimal cytopathic effect of Ti and Ti-Ca samples.
The observed values of cell viability are below 30% and according to the analyzed Ti-based
samples can be considered as noncytotoxic. Significantly lower value of LDH and
consequently low percentage of cytotoxicity in the culture with the Ti-Ca samples compared
to the Ti samples indicate that described modification of Ti samples would have a positive
effect on reducing the already low cytotoxicity of Ti-based substrates.
72 Physicochemical and biological investigations of novel endodontic cement
containing calcium silicate, calcium carbonate and radiopacifier
Djordje Antonijević1, Marija Radoičić2, Marija Prekajski2, Božana Čolović2
1
Laboratory for Anthropology, Institute of Anatomy, School of Medicine, University of
Belgrade, Belgrade, Serbia
2
The Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Calcium silicates are widely investigated for the use in dentistry but their clinical
application is limited by long setting time and poor radiopacity. To overcome these
disadvantages, previously synthesized calcium silicate cement was mixed with calcium
carbonate to increase its setting time and ytterbium trifluoride was added as a radio pacifier.
So obtained cement was investigated from the aspect of setting time, radiopacity,
micromechanical properties and porosity. Phase analysis of the cement after hydration was
performed by XRD and FTIR and its morphological and micromechanical characterization
was done by SEM, Reference Point Indentation and micro computed tomography. To
investigate its biological properties, osteoblasts and osteoclasts like cells were grown on the
cement surface. Biodentine was used as a control. The results showed that addition of calcium
carbonate and ytterbium trifluoride improved radiopacity and setting time of the cement.
Wettability of the cement was superior to that of Biodentine, but Biodentine showed superior
micromechanical properties and porosity. Osteoclasts and osteoblasts like cells adhered to the
cement surface without any evident differences in their morphology. All these make this
cement a promising candidate for dental application.
73 Efficiency of carbamid and hydrogen peroxide in bleaching method in
endodontic treated teeth
Nataša Knežević, Aleksandra Đeri, Željka Kojić, Renata Josipović, Irena RadmanKuzmanović, Valentina Veselinović
University of Banja Luka, Faculty of Medicine, Dentistry department,
Banja Luka, Republic of Srpska
Carbamid and hydrogen peroxide are commonly used for dental bleaching. Hydrogen
peroxide effectively denatures proteins and can penetrate through hard dental tissues.
Ionization gives perhidroxide ion and superoxide ion, which leads to changes in the
configuration of the elektrolyte in macromolecules. There is a change of absorption energy of
macromolecules and that moves visible absorption spectrum from longer towards shorter
wavelengths. That leads to creation of smaller molecules which reflect less light, and that
results in achievement of dental bleaching effect. Carbamid peroxide “in situ” decomposes
into urea, ammonia, carbon dioxid, water and hydrogen peroxide which is here active
substance for dental bleaching.
The aim of this study was to determine the effect of bleaching of endodontic treated
teeth based on the degree of change in hue, but in function of different bleaching agents.
The study was conducted on 20 extracted, endodontic treated human teeth. The teeth
were bleached with internal bleaching method with 30% carbamid peroxide, and with 35%
hydrogen peroxide. Agent was applied to the chamber at palatal side and cavity was closed
with temporary filling for seven days. The procedure was repeated three times for every tooth.
After bleaching method, teeth were restored with composite materials. The dye of tooth was
determined using Vita key for dental dye before and after dental bleaching treatment and also
after each session.
The teeth bleached with 35% hydrogen peroxide were discolored for one (30%) and
two (70%) grades, while the teeth bleached with 30% carbamide peroxide were discolored
with one (44.4%), two (33.3%) and three (22.3%) grades. The results of chi-square tests
showed that there was no statistically significant difference between the solution of 30%
carbamide peroxide and 35% hydrogen peroxide in efficiency of dental internal bleaching
method.
Solutions of carbamid peroxide and hydrogen peroxide are equally effective in
bleaching endodontic treated teeth with internal bleaching method.
74 Quality of bond strength between composite materials and teeth bleached
with internal technique with 30 % solution of carbamide peroxide
Nataša Knežević, Aleksandra Đeri, Željka Kojić, Renata Josipović, Irena RadmanKuzmanović, Valentina Veselinović
University of Banja Luka, Faculty of Medicine, Dentistry department,
Banja Luka, Republic of Srpska
Quality of bond strength between composite material and bleached tooth depends on
changed micromorphological structure of enamel and dentin under the influence of bleaching.
Bleaching methods can reduce adhesion of composite material for hard dental tissues, and the
presence of hydrogen peroxide can affect the polymerization of composite materials.
The aim of this study was to determine the quality of bond strength between
composite material and tooth bleached with internal bleaching method with 30% carbamide
peroxide.
The study was conducted on 20 extracted, endodontically treated human teeth. The
teeth were divided into two groups: a group of teeth bleached with internal bleaching method
with 30% solution of carbimide peroxide (10 teeth) and control group (10 teeth). Agent was
applied to the chamber at palatal side and cavity was closed with temporary filling for seven
days. The procedure was repeated three times for every tooth. After bleaching method,
preparation in class V cavities is done and teeth were restored with nanocomposite material
TetricEvoCeram. The examination of mikroleakage was performed using dying in silvernitrate, and results were read with a stereo, at incisal and gingival part of restoration. The
linear dye penetration at the incisal wall of treated teeth (7.25 µm) was greater than at incisal
wall of teeth from control group (5.75µm), but without statistically significant difference.
Linear dye penetration at gingival wall of treated teeth (20.00 µm) was greater than at
gingival wall of control group (14.25 µm). This difference was statistically significant
(p<0.05).
Larger mikroleakage, or lower quality of bond strength was observed in teeth bleached
with internal bleaching method with 30% carbamide peroxide than in teeth which were not
treated with bleaching method.
75 Histological evaluation of the response of dental pulp of rats after direct
pulp capping with MTA
Aleksandra Đeri, Nataša Knežević, Irena Radman-Kuzmanović, Renata Josipović
University of Banja Luka, Medical faculty, Department of dentistry,
Banja Luka, Republic of Srpska
The aim of this study was to verify the efficiency of material – mineral trioxide
aggregate, MTA, in direct pulp capping Wistar rats’ teeth. The study was conducted on 11
rats, specifically 22 paired first molars on which the procedure of direct pulp capping is
performed. MTA is placed on 22 molars (experimental group) while 6 molars represented
control group. Histological analysis was performed in two observation periods (after 14 and
after 30 days) after placing MTA. Inflammatory changes in the pulp tissue were graded into 4
levels. Sections of the pulp were analyzed at the electron microscope at various
magnifications.
Histological analysis of 80 sections of dental pulp at healthy rats with direct pulp
capping with MTA after observation period of 14 days indicated that fibrin matrix can be seen
in 61 sections in the region of contact with the pulp capping material. There were found initial
signs of inflammation in 15 sections, and inflammation was expressed in 4 sections. There
weren’t signs of necrosis in any sections. After observation period of 30 days, completely
formed dentin bridge was observed at the site of perforation in 58 sections, initial signs of
inflammation were observed in 16 sections and inflammation was observed in 6 sections.
Histological analysis of the response of the dental pulp of rats after direct pulp capping
with MTA pointed to effective odontogenesis and dental bridge formation at the site of
perforation.
76 Marginal seal evaluation of direct composite veneers
Renata Josipović, Irena Radman-Kuzmanović, Ognjenka Janković,
Aleksandra Đeri, Nataša Knežević
Department of Restorative Dentistry, Dental Study Program, Faculty of Medicine,
University of Banja, Republika of Srpska
Advance of new nano-composite dental materials and adhesive systems provide better
quality of bond between dental hard tissue and this materials as well as possibility of
minimally preparation of dental hard tissue. The aim of this study was to evaluate the
marginal seal using dye method of direct composite veneers of intact and abraded anterior
teeth polymerized with classical and soft start light curing technique.
The study was conducted on 40 extracted human anterior teeth. Teeth were extracted
for periodontal reasons and divided into two groups: intact teeth (20) and abraded teeth (20).
Ten teeth in each group were polymerized with classical and soft start technique of
polymerization. Dye penetration was measured using stereo loupes with micrometer scale and
six times magnification.
Linear dye penetration of direct composite veneers in intact teeth polymerized with
classical technique of polymerization on the gingival wall was 2.50 µm, while on the incisal
wall was 0.5 µm. Linear dye penetration in intact teeth polymerized with soft start technique
of polymerization on the gingival wall was 2.25 µm, while on the incisal wall was 2.0 µm.
Average dye penetration of direct composite veneers in abraded teeth polymerized with
classical technique of polymerization on the gingival wall was 3.0 µm, while on the incisal
wall was 1.25 µm. Linear dye penetration in abraded teeth polymerized with soft start
technique of polymerization was greater on the gingival wall (3.50 µm), than on the incisal
wall (3.25 µm).
After use of classical and soft start technique of polymerization direct composite
veneers the lower micro crack was observed on the incisal wall, than on the gingival. The
lower dye penetration was observed in the group intact teeth polymerized with classical
technique of polymerization.
77 The importance of definitive restoration in the treatment of deep caries
Irena Radman-Kuzmanović, Aleksandra Đeri, Nataša Knežević, Renata Josipović
University of Banja Luka, Faculty of Medicine, Dental Clinic, Dentistry department,
Banja Luka, Republic of Srpska
The aim of this study was to determine whether the outcome of the treatment of deep
caries depends on the type of material for the definitive restoration of treated tooth. Clinical
trials included 29 patients of both sexes, aged 16 to 40. Study was conducted at the Faculty of
Medicine, study program of dentistry at 45 permanent morphologically different teeth with
deep caries. Every tooth was radiographed before the treatment. Personal data, status of teeth,
information about drugs and materials, and subjective complaints were entered in the patient
medical records. After the indirect pulp capping treatment, 25 teeth were restored with
composite resin Charisma and 20 teeth with composite resin Tetric Evo Ceram. At the checkups after 3, 6, and 12 months were recorded all subjective observations of the patient, the
occurrence of pain and the condition of filling, in other words, condition of composite resin.
Analyses of obtained results showed that more successful outcome of deep caries
treatment was in teeth restored with a composite resin Charisma (94,1%) than with composite
resin Tetric Evo Ceram (77,3%). Results of the analyses of frequency sensitivity to stimuli
showed that after three months sensitivity was present in 15,6 % of cases, while in the next
two observational period sensitivity was not recorded. After 3 and 6 months, there was no
fracture of the crown, but after 12 months the fracture was observed in 11,1% of teeth. Teeth
restored with composite resin Charisma showed slightly greater success in deep caries
treatment compared to Tetric Evo Ceram. None of the material did not show any significant
advantage, but confirmed that the quality of restoration is an important prerequisite for
successful deep caries treatment.
78 The examination of sensitivity to corrosion of nickel-titanium and stainless
steel endodontic instruments in root canal irrigating solutions
Jelena Popović1, Goran Radenković2, Jovanka Gašić1, Slavoljub Živković3, Aleksandar
Mitić1, Marija Nikolić1, Radomir Barac1
1
Department of Restorative Dentistry and Endodontics, Clinic of Dentistry, Medical Faculty,
University of Niš, Niš, Serbia
2
Mechanical Faculty, University of Niš, Niš, Serbia
3
Department of Restorative Dentistry and Endodontics, Faculty of Dentistry, University of
Belgrade, Belgrade, Serbia
The application of irrigating solutions is essential in chemomechanical treatment of
root canal. However, chemical and electrochemical aggressiveness of the solutions, which
directly act on instruments, may damage their surface.
The aim of this study was to investigate the sensitivity of the nickel-titanium (Ni-Ti)
and stainless steel endodontic files to corrosive action of the sodium hypochlorite (NaOCl),
chlorhexidine gluconate (CHX) andethylenediaminetetraacetic acid (EDTA).
Testing of sensitivity to corrosion of the instruments was performed by dynamic
potentiometric method. Measurements werecarried out by means of the linear sweep
technique with a sweep rate of 0,2mV/s. Anodic polarization curves were recorded and the
potentials at which a sharp rise in current occurred, called the pitting potentials, were
determined. The sharp rise of the potential occurs due to the beginning of the local dissolution
of the metal and forming of the pits.Measurements were made in 5.25% NaOCl, 0.2% CHX
and 17% EDTA.
The most intensive corrosive changes and the lowest value of pitting potential of 1.1 V
showed Ni-Ti instruments immersed in 5.25% NaOCl. Slightly lower value of pitting
potential of 1.3 V showed stainless steel instruments immersed in 5.25% NaOCl. Higher
value of the pitting potential of 1,7 V and lower corrosive surface changes showed stainless
steel instruments immersed in 0.2% CHX, whereas nickel-titanium instruments immersed in
0.2% CHX showed the pitting potential of 2 V.The corrosion was not observed in both types
of instruments after immersion in 17% EDTA.
The useof 5.25% NaOCl and 0.2% CHX may cause severe surface corrosion of Ni-Ti
and stainless steel endodontic files. The use of EDTA did not cause corrosion of the surface
of both types of instruments.
79 SEM examination of the surface corrosion of endodontic filers after
immersion in irrigating solutions
Jelena Popović1, Goran Radenković2, Jovanka Gašić1, Slavoljub Živković3, Aleksandar
Mitić1, Marija Nikolić1, Radomir Barac1
1
Department of Restorative Dentistry and Endodontics, Clinic of Dentistry, Medical Faculty,
University of Niš, Niš, Serbia
2
Mechanical Faculty, University of Niš, Niš, Serbia
3
Department of Restorative Dentistry and Endodontics, Faculty of Dentistry, University of
Belgrade, Belgrade, Serbia
Chemomechanial canal preparation during root canal treatment includes procedures of
cleaning and shaping with endodontic instruments and irrigation solutions. The functions of
the irrigants are to act as lubricants, to dissolve tissue and remove debris, and to promote root
canal sterility. However, the chemical effects of the irrigating solutions may damage the
instruments surface and hinder their performance.
The purpose of this study was to evaluate surface of the endodontic instruments after
immersion in different irrigating solutions using scanning electron microscope (SEM).
The study included nickel-titanium and stainles steel hand endodontic files. After
immersion in three most used irrigating solutions (5.25% NaOCl, 0.2% chlorhexidine
gluconate (CHX) and 17% EDTA), the instruments were subjected to SEM examination.
SEM examination of the samples revealed general severe corrosion in form of spots,
pits and cracks on the instrument surface after immersion in 5.25% NaOCl. Corrosion had
also occured in local regions on the surface of the instruments after immersion in 0.2% CHX.
SEM analysis revealed no corroded areas on the surface of the instruments treated with 17%
EDTA, and those instruments were similar to control samples.
The useof 5.25% NaOCl and 0.2% CHX may cause intensive surface corrosion of
endodontic files. The use of 17% EDTA did not cause corrosion of the instrument surface.
80 Modified porous apatite biomaterials: An in vivo biocompatibility study
Milena Aleksić1, Andrea Žabar Popović1, Perica Vasiljević1, Ljubiša Đorđević1,
Stevo Najman2, Vukoman Jokanović3
1
Department of Biology and Ecology, Faculty of Science and Mathematics, University of Niš,
Niš, Serbia
2
Institute of Biomedical Research, Medical Faculty, University of Niš, Nis, Serbia
3
Vinča Institute of Nuclear Sciences, Laboratory of Radiation Physics and Chemistry,
Belgrade, Serbia
During recent years a number of different synthetic biomaterials for the regeneration
and repair of tissues, particularly bone tissue, have been developed. Biomaterials based on
calcium phospate (apatite) were shown to be the most effective in bone tissue reparation. The
aim of the study was to examine the biocompatibility of two materials based on porous
apatite: porous apatite thin alginate film (PA + A) and porous apatite with a thin film of
polylactide co-glycolide (PA + PLLA) in vivo. Both biomaterials were implanted in BALB / c
mice subcutaneously in the interscapular region and intraperitoneally. Biomaterials were
divided into two test groups. The first group consisted of materials implanted alone, and
second group contained tested materials with blood plasma. After two week period, the mice
were sacrificed and implants with surrounding tissue were surgically removed. The tissues
were fixed in 10% neutral formalin, decalcified in formic acid and further processed by
routine histological protocol. Histological sections were visualized using two different
staining techniques: Harris haematoxylin / eosin and Masson Trichrome. Obtained sections
were observed using light microscopy. Histopathological analysis revealed the presence of
giant multinuclear cells and moderate production of collagen. Mild resorption of biomaterials
was observed. All this findings indicated the presence of moderate inflammatory response. At
the end of the two week period we did not notice a significant difference between the
biomaterials which were implanted with blood plasma and biomaterials without blood plasma.
81 Biocompatible Materials – Metals
Aleš Stambolić, Monika Jenko
IMT, Ljubljana, Slovenia
The biomaterials in medicine were used already 4000 years ago unaware of their
properties. It is now only 150 years that we are researching the interactions between the host
tissue and materials. The main groups of biomaterials are metals, ceramics and polymers.
Metals have excellent strength and are used as load-bearing materials; ceramics are hard but
brittle and are often used in dentistry, while polymers are quite soft composite materials.
Problems with biomaterials appear in aggressive environments and the consequences are
corrosion, wear, fatigue and release of toxic ions into the human body. To reduce the failure
of a biomaterial, a passive layer should be deposited on its surface. This is achieved by
oxidation process where the oxide layer forms on the surface and protects the bulk material
from further degradation. Oxidation kinetics of metals obeys three different laws depending
on the temperature of oxidation: linear, parabolic and logarithmic law. Logarithmic law
usually represents oxidation in thin layer regime at low temperatures. In parabolic law, the
oxide growth occurs with a continuing decreasing oxidation rate. Linear law appears when
rate of oxidation remains constant with time.
82 Heavy metals nickel and cobalt induce epileptiform activity in leech
Retzius neurons
Marija Stanojević1, Srđan Lopičić1, Svetolik Spasić1, Isidora Aleksić1, Milica Prostran2,
Vladimir Nedeljkov1
1
Institute for Pathological Physiology “Ljubodrag Buba Mihailović'', Faculty of Medicine,
University of Belgrade, Serbia
2
Institute for Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine,
University of Belgrade, Serbia
Heavy metals nickel and cobalt are environmental pollutants, but human exposure to
them is particularly high when it is occupational. Nickel and cobalt toxicity can produce a
variety of adverse effects on human health, including epileptic seizures.
The object of the present study was to examine the effects of heavy metals nickel and
cobalt on intracellularly recorded activity of Retzius neurons of the leech Haemopis
sanguisuga.
Experiments were performed in two separate trials. The addition of 3 mM NiCl2 or 3
mM CoSO4 into the superfusing saline induced epileptiform activity. Epileptiform activity
was characterized by the generation of membrane potential oscillations in a form of
paroxysmal depolarization shifts (PDSs). Frequency, duration and amplitude of PDSs were
measured, as well as the duration of PDS intervals. A PDS interval was defined as time period
from the beginig of one PDS to the beginning of the next one. The intensity of PDS activity
was calculated as a percentage of PDS duration within its belonging PDS interval. All data are
presented as average±SEM.
Both Ni2+ and Co2+ induced epileptiform activity in leech Retzius neurons.
Epileptiform activity consisted of repetitive PDSs. Nickel-induced PDSs had an average
frequency of 5.53±0.39 min-1, average duration of 5.38±0.26 s, and an average amplitude of
12.90±0.77 mV. Average intensity of Ni2+-induced PDS activity was 48.20±1.54 % (n=10).
Cobalt-induced PDSs had an average frequency of 3.61±0.35 min-1, average duration of
3.71±0.34 s, and an average amplitude of 6.14±1.07 mV. Average intensity of Co2+-induced
PDS activity was 22.11±2.47 % (n=6).
Nickel and cobalt disturb spontaneous electrical activity of leech Retzius neurons,
inducing epileptiform activity. As a convulsant nickel proves to be more potent than cobalt on
our cell epilepsy model.
83 Application of nanotechnology in medicine
Dragana Jordanov1, Branislav Milovanović2, Branko Matović1, Milena Rosić1,
1
Institute of Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
2
University Medical Center B. Kosa, Neurocardiological laboratory, Medical faculty,
University of Belgrade
X-difractometry (XRD) is widely used in material science like the one of the most
sensitive and foolproof method in nanotechnology. But XRD also have numerous applications
in medicine, optics, electronics, chemistry and biology. In this work the crystal structure of
industrial produced drug Midodrine (Gutron) has been investigated by X-ray methods and
comparing with placebo forms obtained from sucrose. Properties such as lattice parameters,
chemical composition and crystal phase of that samples were monitored by X-ray powder
diffraction on a Siemens D-500 XRPD difractometer with Cu Kα1,2 radiation, at room
temperature. The measurements were performed in the range 2-600 2θ in a continuous scan
mode with a step width of 0.020 and 0.5 s/step. The results were analysed using the software
package Powder Cell. The difference in structure between sucrose and placebo forms was
noticed.
84 Calcium oxalates urolithiasis - assessment of some renal cell injury
Vatroslav Šerić1,2, Vesna Babić-Ivančić2,3
1
Clinical Hospital Center Osijek, Division of Clinical Laboratory Diagnostics,
Osijek, Croatia
2
Faculty of Medicine Osijek, Osijek, Croatia
3
Ruđer Bošković Institute, Zagreb, Croatia
Urolithiasis is a chronic, relapsing disease in which mineral aggregates are formed in
the urinary tract. It represents one of the pathologic biomineralisation forms. However,
despite that many intensive researches have been conducted, all mechanisms of the formation
and growth of the stones have not yet been discovered due to its complex and multifactorial
process.
An important factor in the formation of the stones is retention of formed crystals in the
urinary tract. Renal cells damage induced by oxidative stress due to the presence of a
crystallization promoter in higher concentrations in the urinary tract and inflammation
resulting from greater predisposition for crystal-cell interactions, as shown by sensitive
biomarkers of renal damage such as L-FABP, n-GAL, cystatin C.
In this paper the degree of damage to the epithelial cells of renal tubules caused by
toxic effects of hyperoxaluria in patients with calcium urolithiasis using the some biomarkers
of kidney damage as a new way of assessing the propensity to formation urinary and / or
kidney stones. Results metabolic parameters of urolithiasis in the first morning urine of the
patients showed higher values of promoting factors for calcium lithiasis, index risk, as well as
increased levels of biomarkers of values obtained for the same parameters in controls.
In conclusion it can be said that it is possible, based on the assessment of the degree of
renal tubular cells with the investigated biomarkers, to predict the possible retention of the
generated crystals in the urinary tract of people with calcium urolithiasis
85 The encrustates on urological double J stent - physco-chemical analyses
Hrvoje Kuveždić1, Jasminka Kontrec2, Dalibor Šimunović1, Vesna Babić-Ivančić2,3
1
Clinical Hospital Center Osijek, Urology Clinic, Osijek, Croatia
2
Ruđer Bošković Institute, Zagreb, Croatia
3
Faculty of Medicine Osijek, Osijek, Croatia
In humans, one of the pathological forms of biomineralization in the body is a process
in which the complex chemical systems, such as the urine, precipitated inorganic salts such as
the kidney and / or urinary stones of different composition. This process is influenced by
physico-chemical, genetic, endocrine, anatomic, climate, inflammatory and others factors.
The disease is defined as urolithiasis and is still a serious health, social and sociological
problem.
Double J stent has been established as very valuable medical tool in treatment of
numerous urological conditions. As such it has its advantages and drawbacks. The
complications of double J stent are well documented and in the most cases are not lifetreating. The most common “technical” complication is formation of stent encrustations
which render stent nonfunctional. The stent encrustation is most easily prevented by stent
replacement. The etiological factors of the stent encrustation, besides biofilm formation and
inflammation, are not well documented. The aim of this research was to analyze selected
etiological factors and their role in the stent encrustation. The secondary objective was to test
the hypothesis that chemical composition of the encrustate must be same as of primary stone,
with premise that alkali urine will favor the phosphate stones.
Deposits on JJ stent removed from the urinary tract in selected groups of patients were
characterized by thermal FT-IR spectroscopic analysis and gravimetric analysis (TG) . The
composition of the encrustates on the urological stents were compared with the composition
of urinary stoneand it is shown that they are not consistent.
In conclusion it can be said that some of the parameters were not significantly
different in patients with and without encrustates. The most common encrustate component is
apatite, then struvite, and least common are calcium oxalate encrustates. The compositions of
the encrustates were not always identical at different levels.
86 Synthesis and characterization of multiferroic BiFeO3 powders
fabricated by hydrothermal and mechanochemical method
Maria Čebela1, Radmila Hercigonja2, Svetlana Ilić1, Miljana Mirković1, Mia Omerašević1,
Branko Matović1
1
Laboratory of Materials Sciences, Vinča Institute of Nuclear Sciences, University of
Belgrade, Belgrade, Serbia
2
Faculty of Physical Chemistry, University of Belgrade, Belgrade, Serbia
Bismuth ferrite (BiFeO3) is one of the most investigated single-phase multiferroic
materials. BiFeO3 nanopowder have been successfully synthesized by the hydrothermal and
solid state synthesis methods. We analyzed the particles size using granulometric analysis,
scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The
phase composition of the sintered samples was determined by x-ray diffraction (XRD)
analysis. It revealed that synthesized material crystallize in space group R3c with cell
parameters a = b = 5.5780(10) Å and c = 13,863(3) Å. The powders behavior was
characterized by TG/DTA and Heating stage microscope. The magnetic behavior of
synthesized material is done by means of SQUID device and using a vibrating sample
magnetometer (VSM).
87 Thermal transformation of Cs-Exchanged zeolite
Mia Omerašević1, Bojana Nedić Vasiljević2, Svetlana Ilić1, Maria Čebela1, Miljana
Mirković1, Ana Radosavljević-Mihajlović1, Branko Matović1
1
Laboratory for Material Science, Institute of Nuclear Sciences “Vinča”, University of
Belgrade, Belgrade, Serbia
2
Faculty of Physical Chemistry, University of Belgrade, Belgrade, Serbia
Cesium aluminosilicate phases are of great interest as possible hosts for 137Cs
immobilization in radioactive waste management. Cs+ exchanged forms of two synthetic LTA
zeolites (4A and 5A) were prepared by ion exchange procedure. Synthesized samples were
thermally treated in temperature range of 600ºC-1400ºC. High temperature phase
transformations of Cs+ exchanged zeolites (Cs-LTA) were investigated. Based on data
obtained by FTIR, TG-DTA, SEM/EDS and XRPD analysis of the samples, it was concluded
that above 1000 ºC Cs-LTA (4A and 5A) frameworks recrystallized into a pollucite phase.
88 Synthesis of Monetite (CaHPO4) by mechanochemical treatment of
Brushite (CaHPO4·2H2O)
Miljana Mirković1, Anja Došen1, Biljana Babić1, Maria Čebela1, Mia Omerašević1,
Branko Matović1, Aleksandra Rosić2
1
Laboratory of Materials Sciences, Vinča Institute of Nuclear Sciences,
University of Belgrade, Belgrade, Serbia
2
Department of mineralogy and crystallography, Faculty of Mining and Geology,
University of Belgrade, Belgrade, Serbia
In the field of biology and medicine different types of calcium phosphates materials
(CaP) play a very significant role. They can be found in a human body as one of the
crystalline components of human enamel, dentine, cementum and bones and as a pathological
product – phosphatic renal stones. Calcium phosphates such as brushite (CaHPO4·2H2O) and
monetite (CaHPO4) are of great scientific interest in the field of biomaterials. Main objective
of this study is a synthesis of monetite by mechanochemical treatment of synthesized brushite.
When brushite loses its structural water it transforms to monetite. Pure synthesized brushite
nanomaterial was obtained, and the particle size was modified by grinding in the vibrating
mill. The sample was ground five times for 2.5 minutes and analyzed by XRD between
grinding. Crystallite sizes were determined from the XRD patterns using Scherer equation.
After about 5min of grinding an increase in temperature causes a phase transformation from
brushite to monetite, after 12.5 min of grinding we get monetite material. BET method
indicates that synthesized brushite is micro porous. After 5 minutes of milling brushite is
mezzo porous, these results were confirmed by SEM images. Mechanochemical treatment and
phase transformation of brushite to monetite is cost-effective and much faster than the
standard methods for synthesize monetite.
89 Young’s modulus evaluation and thermal shock behavior of a porous
SiC/cordierite composite materials
Milica Pošarac-Marković1, Jelena Majstorović2, Aleksandar Devečerski1, Branko Matović1,
Tatjana Volkov –Husović3
1
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
2
University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia
3
University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
Porous SiC/Cordierite Composit samples with graphite content (10%) were
synthesized. Evaluation of Young modulus of elasticity and thermal shock behavior of these
samples will be presented. Thermal shock behavior will be monitored using water quench
test, and non destructive methods such are UPVT and image analysis will also be used for
accompaniment the level of destruction of the samples during water quench test. Based on the
level of destruction graphical modeling of critical number of cycles will be given. This
approach will be implemented on discussion of the influence of the graphite content on
thermal stability behavior of the samples.
90 Dopant effect of iron on the formation of sol-gel derived mullite
Svetlana Ilić, Slavica Zec, Vesna Maksimović, Maria Čebela, Mia Omerašević,
Aleksandra Šaponjić, Branko Matović
University of Belgrade - Institute of Nuclear Sciences “Vinča”, Materials Sci. Lab.,
Belgrade, Serbia
Precursor powders of pure and iron doped mullite were prepared using sol-gel
combustion method. Firstly, the solutions of the synthesized iron doped mullites (composition
6-15 wt % of Fe2O3) were obtained by dissolving of Al(III) nitrate, Fe(III) nitrate and TEOS
in ethanol. Afterwards, water and urea were added. The prepared solutions were heated on a
hot plate to evaporate solvents and obtain gels that were further heated to initiate combustion
process. During the heating on a hot plate nitrates have been decomposed emitting brown
gases. As-prepared ashes were heat treated at 800 °C for 4 h to remove the remaining organic
residues and retained nitrogen. Sintering of uniaxially pressed pellets (8 mm, 135 MPa) was
performed at 1550 °C for 4 h. XRD analysis confirmed that all as-synthesized powders were
amorphous while a single mullite phase appeared in the sintered samples. Also, the lattice
parameters of doped mullites increase with increasing iron content due to replacement of Al3+
- by larger Fe3+ -ions in mullite lattice. TGA/DSC analysis showed lowering of crystallization
temperature of iron doped mullite with increasing iron content. The SEM micrographs of the
sintered samples reveal elongated lath-like mullite grains that enlarge and become better
packed with enriching of the reaction mixtures by iron. Densities of sintered samples have
also increased.
91 Sintering and magnetic behavior of Ca1-xGdxMnO3 (x=0.05, 0.1, 0.15, 0.2)
nanopowders
Milena Rosić1, Ljiljana Kljaljević1, Dragana Jordanov1, Milovan Stoiljković1,
Vladan Kusigerski2, Vojislav Spasojević2, Branko Matović1
1
Laboratory for Material Science, Institute of Nuclear Sciences „Vinča“, University of
Belgrade, Belgrade, Serbia
2
Laboratory for Physical Chemistry, Institute of Nuclear Sciences „Vinča“, University of
Belgrade, Belgrade, Serbia
3
Condensed Matter Physics Laboratory, Institute of Nuclear Sciences “Vinča“, University of
Belgrade, Belgrade, Serbia
The synthesis, sintering temperatures and magnetic properties of Ca1-xGdxMnO3
(x=0.05; 0.1; 0.15; 0.2) perovskite has been investigated. Powders were prepared using a
modified glycine nitrate procedure. Sintering of the green bodies was carried out by
conventional sintering (CS) method with a special emphasis on the effects of sintering
temperature (1300–1400 oC). CS was applied on nanocrystalline system of Ca1-xGdxMnO3
(x=0.05; 0.1; 0.15; 0.2) to control the accelerated grain growth and high-density occurring
during the final stage of sintering. All samples where characterized by ICP, XRD, FTIR,
SEM, EDS and SQUID magnetometry. Magnetic measurements show the existence of a
phase transition antiferromagnetic - paramagnetics at a temperature TN = 105 K. The value of
the effective magnetic moment of the manganese ions is between the values of Mn3+ and
Mn4+ ions, which show their mixed valence of the tested compound. Properties of the
synthesized powders together with sintering and magnetic tests are discussed.
92 Synthesis and Characterization of Sphene Based Ceramics
Jelena Pantić, Jelena Luković, Maria Čebela, Tamara Minović, Miljana Mirković,
Svetlana Ilić, Milena Rosić
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder
mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of
precursors. Also, mechanical activation of precursors has been used for the preparation of Crdoped sphene ceramic pigments (CaTi1−yCrySiO5). The mechanochemical process initially
yielded amorphous powders, which on further calcination, crystallized to yield sphene
ceramic. Low and high pressure sphene ceramics are obtained by pressureless and high
pressure - high temperature synthesis process (at 4 GPa, 1200°C). The resulting room (P21/a)
temperature phase is thermally unstable and it transforms to high (A2/a) pressure-temperature
phase.
The evolution of the phase composition with thermal treatment was investigated by Xray powder diffraction (XRPD). Powder morphology and particle size distribution were
analyzed by scanning electron microscopy (SEM) and laser diffraction, respectively. Rietveld
refinement was employed to get the structural information of the synthesized powder.
Densification and microstructure evolution was determined by means of density and scanning
electron microscopy (SEM). UV/Vis reflectance spectra are used to determinate the behavior
of the chromium ion. The color efficiency of pigments was evaluated by colorimetric analysis
(CIE L * a * b system). Raman and IC measurements were performed to verify phase
transition.
93 Synthesis and characterization of
Ce1-xBixO2-δ solid solution for application in solid oxide fuel cells
Marija Prekajski1, Jelena Pantić1, Jelena Luković1, Marija Stojmenović1,
Goran Branković2, Branko Matović1
1
Institute of Nuclear Sciences ”Vinča”, University of Belgrade, Belgrade, Serbia
2
Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia
CeO2 system doped with Bi3+ can be very interesting for application in SOFC’s due to the
high ion conductivity of CeO2 and Bi2O3 phases. Exactly that was a motivation for synthesis,
characterization and study of sintering properties and ionic conductivity on this solid solution.
Solid solution Ce1-xBixO2-δ nanopowders with the composition of x = 0.1 - 0.5 were
synthesized by using Self Propagating Room Temperature procedure (SPRT). The results
obtained by XRPD show that synthesized samples were single-phase solid solution at room
temperature. Powders were densified by using Conventional (CS) and Microwave (MS)
Sintering techniques at different temperatures, in an air atmosphere for 1 h. Complex
impedance method measurements were carried out on sintered samples. The highest
conductivity was obtained for the ceramic composition Ce0.80Bi0.20O2-δ sintered by microwave
technique at 700 °C. Ionic conductivity measurement showed that conductivity increased
dramatically with increasing temperature as well as with Bi3+ concentration. It seems that Ce1xBixO2-δ solid solution is promising material for application in IT-SOFC’s. 94 Simple tungsten carbide synthesis from tungsten(VI) oxide
Jelena Luković1, Biljana Babić1, Marija Prekajski1, Jelena Pantić1, Marija Stojmenović1,
Igor Pašti2, Branko Matović1
1
University of Belgrade, Institute of Nuclear Sciences “Vinča”, Belgrade, Serbia
2
University of Belgrade, Faculty of Physical Chemistry, Belgrade, Serbia
Tungsten carbide powder has been prepared by straightforward method. Tungsten (VI)
oxide was placed on the activated carbon cloth that was in a carrier and put into the furnace.
Furnace, through which hydrogen flowed, was heated up to 750 °C. Than the flowing gas was
changed to acetylene, and temperature was further raised to 900 °C. The sample was at this
temperature for one hour before the furnace was cooled to the room temperature. Obtained
powder was tungsten carbide.
Composition of the powder was determined by X-ray powder diffraction (XRPD).
Specific surface area and texture of obtained powder were examined by Brunauer–Emmett–
Teller (BET) method. Capacitive and electrocatalytic properties of the sample in alkaline
media were done in a conventional one-compartment three-electrode electrochemical cell.
The GAMRY PCI4 / 750 potentiostats / galvanostat was used in the voltammetric studies.
95 Effect of UV/ozone treatment on the surface energy and nanoscale
topography of gold implanted polyethylene
Miloš Nenadović, Danilo Kisić, Danka Stojanović, Zlatko Rakočević
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
The effect of ultraviolet (UV) ozone treatment on the surface energy and nanoscale
topography of gold implanted high density polyethylene (HDPE) was investigated, by atomic
force microscopy (AFM) and contact angle measurement. HDPE samples were modified by
the implantation of gold ions at a dose of 5×1015 ions/cm2, using energies of 50, 100, 150, and
200 keV, and subsequently treated with UV/ozone. Surface energy of the samples was
calculated from contact angle measurements, using Owens-Wendt model. After gold
implantation surface energy decreases, with higher percentage of polar component, while after
UV/Ozone treatment surface energy increases, and polar component percentage increases to
above 95 %. AFM showed that the surface is significantly damaged after implantation, while
UV/ozone treatment caused significant changes visible by formation of small hemispherical
structures on the surface.
96 Structural, optical and electrical properties of argon implanted
TiN thin films
Maja Popović, Mirjana Novaković, Nataša Bibić
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Modification in structural, optical and electrical properties of titanium nitride (TiN)
thin films induced by argon ion irradiation and thermal annealings were studied using various
experimental techniques. TiN thin films deposited by dc reactive sputtering on Si substrate
were implanted with argon ions at 200 keV. As-implanted samples were annealed before or
after ion irradiation at 600 oC and 700 oC, respectively. Rutherford backscattering
spectrometry, X-ray diffraction, cross-sectional (high-resolution) transmission electron
microscopy, spectroscopic ellipsometry and electrical measurements were carried out in order
to study structural, optical and electrical properties of TiN/Si samples. After irradiation with
200 keV Ar ions the columnar microstructure of TiN was changed and the presence of smaller
crystalline grains were observed. Partial loss of columnar structure observed in implanted
samples was completely recovered after annealing at 700 oC. Observed changes in
microstructure induced by ion irradiation and annealings were correlated with the variation in
optical parameters obtained by spectroscopic ellipsometry. It was found that both refractive
index and extinction coefficient are strongly dependent on the defects concentration and size
of the crystalline grains in TiN layers.
97 Xenon-ion-induced mixing of Co/Si bilayers
Mirjana Novaković1, Marija Popović1, Kun Zhang2, Nataša Bibić1
1
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
2
II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany
Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface
mixing depend sensitively on the ion and film parameters, including the structure of the
metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si (100)
wafers were bombarded at room temperature with 400-keV Xe+ ions at fluences of up to 3
×1016 ions/cm2. We used either crystalline or pre-amorphized Si wafers, the latter ones
prepared by 1.0-keV Ar-ion implantation. Changes of the bilayer structures induced by ion
irradiation were investigated with Rutherford backscattering spectrometry and high-resolution
transmission electron microscopy. It was found that the mixing rate for the Co/crystalline-Si
couples, Δσ2/Φ = 3.0(4) nm4, is higher than the value expected for ballistic mixing and about
half the value typical for spike mixing. Mixing of layers with pre-amorphized Si is much
weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si
bilayers.
98 Properties of the nanostructured nickel thin films deposited by GLAD
technique
Jelena Potočnik1, Miloš Nenadović1, Bojan Jokić2, Zlatko Rakočević1
1
University of Belgrade, INS Vinča, Laboratory of Atomic Physics, Belgrade, Serbia
1
University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
In this study, structures of the nickel thin films have been obtained using Glancing
Angle Deposition (GLAD) technique. Glass substrates were positioned 75 degrees with
respect to the substrate normal. The substrates were rotated with a suitable constant speed
followed by intervals without rotation. The durations of rotations were 10 minutes, 30
minutes and 1 hour, for the different samples, while the total time of deposition was kept
constant. During the deposition time of 1 hour 30 minutes nickel thin films with a thicknesses
of 260 nm, 230 nm and 210 nm were obtained. The deposited nickel thin films were
characterized by Scanning Electron Microscopy and Atomic Force Microscopy. Magnetic
properties of the thin films were observed by Magneto–Optical Kerr Effect Microscope. The
values of the specific resistivity of the samples were found using Four-Point Probe method.
99 Interactions in mixtures of sodium bis (2-ethylhexyl) sulfosuccinate (AOT)
and ionic liquid
Sanja Novak1, Sara Morasi-Piperčić2, Sandro Makarić2, Ines Primožič2, Darija Jurašin3
1
Department of Physical Chemistry, Faculty of Science, University of Zagreb, Croatia
2
Department of Organic Chemistry, Faculty of Science, University of Zagreb, Croatia
3
Division of Physical Chemistry, Ruđer Bošković Institute, Zagreb, Croatia
Surfactants (shorten for surface-active agents) are organic compounds containing in
one molecule both lyophobic (hydrophobic) and lyophilic (hydrophilic) parts. Due to such
amphiphilic structure surfactants exhibit specific properties in solutions, as well as in solid
state. Mixtures of two or more different of surfactants often show a synergistic effect i.e., the
interfacial properties of the mixture are more pronounced than those of the individual
components themselves. As a result, in many industrial products and processes, mixtures of
different types of surfactants, rather than individual materials, are used. Aqueous catanionic
surfactant mixtures, mixtures of opposite charge surfactants, offer numerous possibilities in
mediating molecular self-assembly by varying the molar ratio and/or concentration of
oppositely charged surfactants.Interactions in aqueous mixtures of the cationic surfactant (1dodecyl-3-methylimidazolium bromide, [C12mim]Br) and anionic surfactant (sodium bis (2ethylhexyl) sulfosuccinate, AOT) have been investigated by surface tension, conductivity,
microelectrophoretic and light scattering measurements as well as by optical microscopy. Due
to its molecular structure AOT shows a tendency to form interfaces with minimal curvatures,
such as vesicles and flexible bilayers even in dilute aqueous solutions.2 [C12mim]Br as ionic
liquid (IL) also exhibits unique physco-chemical properties. The term ionic liquid (IL) refers
to a class of substance formed by a large organic cation and either a small anion, such as Br−,
or relatively large one, such as [(CF3SO2)N2]− with melting points under 100 oC, often even
lower than room temperature. In the last decade ILs have attracted increasing interest in
numerous scientific areas such as chemistry, physics, engineering, material science, energy
and fuels, among others. Investigated mixtures display interesting interfacial and phase
behavior properties; i.e. strong synergistic effects were observed for both their interfacial and
bulk properties. Competition between various molecular interactions (hydrophobic,
electrostatic, van der Waals, hydration forces, etc.) results in the formation of mixed
monolayer at the air/solution interface and variety of microstructures and liquid crystall
phases in bulk phase. Phase behaviour observed in the investigated mixtures is not typical for
the catanionic mixtures. In equimolar mixtures gel-like mesophase appears instead of a solid
crystalline precipitate. Also, mixed micelles do not form even in the large excess of one of the
surfactants. However, small and large vesicles are found in a broad concentration range.
Observed behaviour is consequence of chain length asymmetry and great solubility mismatch
between surfactants in mixtures. 100 Stability of titanate nanowires in aqueous medium
Natali Nakić1, Darija Jurašin2, Maja Dutour Sikirić2, Atiđa Selmani1
1
Department of Physical Chemistry, Faculty of Science, University of Zagreb
2
Division of Physical Chemistry, Ruđer Bošković Institute, Zagreb, Croatia
Recently, nanostructural TiO2 materials of different morphologies (nanoparticles,
nanotubes, nanosheets, nanowires) have been synthesized. These materials attract
considerable interest due to their unique phyisico-chemical properties and numerous possible
applications. However, the success of their application, as well as possible toxicity and
environmental impact, depend on particle size and stability in the medium of interest.
Stability of nanoparticles is affected by concentration of the particles themselves, composition
(presence of the ions and organic material), pH and ionic strength of the medium.
The influence of the medium of different ionic strength and pH (Mili Q water and
phosphate buffer saline, PBS) on the satbility of titanate nanowires has been investigated.
Titanate nanowires have been synthetised by hidrothermal method. Structure and composition
of nanowires have been determnined by powder X-ray diffraction, infrared and Raman
spectroscopy. Morphology of nanowires has been visualised by scanning electron microscopy
and specific surface has been determined by BET. Nanowires stability in water and PBS has
been monitored for 24 hours by dynamic light scattering. The influence of nanowires
concentration has also been determined.
Size of titanate nanowires in both media is decresing woth the time. No significant
difference in stability of nanowires between investigated media was observed.
101 Nanostructured carbon materials in electroanalysis – proof of concept for
sensing of bismuth ion
Nevena Markičević, Biljana Šljukić, Radmila Hercigonja, Gordana Ćirić-Marjanović
University of Belgrade, Faculty of Physical Chemistry, Belgrade, Serbia
Different carbon electrodes were explored for application in electroanalysis, namely
for sensing of bismuth ion as model analyte. The carbon materials tested included glassy
carbon, edge and basal plane pyrolytic graphite, as well as prepared carbonized
nanostructured polyaniline. Polyaniline was synthesized by the oxidative polymerization of
aniline in the presence of 3,5-dinitrosalicylic acid, and then carbonized in nitrogen
atmosphere by means of gradual heating up to 800 °C.
Bismuth ion was chosen as model analyte as protocol for its detection and
quantifications is still to be determined. Herein, anodic stripping voltammetry was used with
optimization of several parameters such as deposition potential and time.
Electrode based on carbonized polyaniline showed the highest catalytic activity for bismuth
ion sensing in terms of the highest current densities recorded, both in a laboratory and in real
sample.
102 Synthesis and characterization of barium titanate thin films obtained by
wet chemical deposition technique
Branimir Bajac1, Jelena Vukmirović1, Đorđije Tripković1, Elvira Đurđić2, Željka Cvejić2,
Srđan Rakić2, Vladimir Srdić1
1
Faculty of Technology, Department of Materials Engineering, University of Novi Sad,
Novi Sad, Serbia
2
Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Serbia
In recent years, interest in electroceramic materials has grown rapidly. The application
of dielectric thin ceramic films for production of specific microchip components, such as
capacitors and sensors, have reduced the size of those components to nanometer scale. The
most research have been performed on BaTiO3, because it possesses high dielectric constant
at room temperature and good electrical polarization. This research presents process of
preparation of BaTiO3 thin films obtained by spin coating deposition technique. Particle size
and viscosity of precursor sols have been characterized by DLS and rotational viscometer,
respectively. After the thermal treatment at 750˚C for 30 minutes, morphology and phase
composition of obtained thin films have been inspected by scanning electron microscopy and
X-ray diffraction analysis. In was concluded that precursors sols were stable in period of
seven days, with insignificant change in particle size and viscosity. Phase composition of
obtained films was free of secondary phases, and there was no chemical interaction with the
silicon substrate. Thickness of BaTiO3 films was around 300 nm, with crack free and uniform
surface, and grain size in range between 50 and 100 nm.
103 Investigation of mechanical and electrical properties of Cu-based
composites reinforced with micro and nano ZrB2 particles
Jovana Ružić1, Jelena Stašić1, Davor Atanasijević2, Karlo Raić3, Dušan Božić1
1
Materials Department, Institute of Nuclear Sciences “Vinča”, University of Belgrade,
Belgrade, Serbia
2
Innovation Center of the Faculty of Technology and Metallurgy, University of Belgrade,
Belgrade, Serbia
3
Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
The Cu-based composites reinforced with micro and nano ZrB2 particles was
consolidated via powder metallurgy processing by combining mechanical alloying and hot
pressing. Powder mixture of copper (94.78 wt.%), zirconium (4.1 wt.%) and boron (1.12
wt.%) was used as a starting material. Mechanical alloying of powder mixture was carried out
at various times– from 5 up to 30 hours and samples were taken on every five hours. All the
specimens of mechanically alloyed powders were hot pressed up to nearly theoretical density
,in argon atmosphere, at the temperature of 950˚C,with retention time 2.5 hours and pressure
of 35 MPa. Mechanically alloyed powders and hot-pressed samples of copper based
composites with 7 vol.%ZrB2 were characterized using X-ray diffraction and scanning
electron microscopy (SEM) equipped with an energy dispersive X-ray
spectrometry(EDS).Mechanical properties of the Cu-7vol.%ZrB2 alloy was investigated, and
results showed that hardness and compressive strength of hot-pressed samples increased as
the milling time increased. Distribution of micro and nano ZrB2 particles and presence of
agglomerates in the Cu matrix directly depend on the milling time and show strong influence
on mechanical properties and fracture of Cu-7 vol.% ZrB2 alloy. Electrical conductivity also
shows the strong dependence of the time of mechanical alloying. Addition of ZrB2 particles
decreases electrical conductivity of copper but despite these fact, Cu-7 vol.% ZrB2 alloy can
be marked as highly conductive alloys (samples made of mechanically alloyed powders
milled longer than 20h).In the present study, the mechanical properties of copper based
composite prepared by hot pressing of mechanically alloyed powders were predicted using
Artificial Neural Network (ANN) approach. Experimental results of specimens have shown a
consistency with predicted results of ANN.
104 Application of new synthesized ferrite nanoparticles for preparation of
modified carbon paste electrode
Dalibor M. Stanković1, Sandra Škrivanj2, Aleksandar S. Nikolić2, Predrag Vulić3,
Dragan D. Manojlović2
1
Innovation Centre Faculty of Chemistry, University of Belgrade, Belgrade, Serbia
2
Faculty of Chemistry, University of Belgrade, Belgrade, Serbia
3
Faculty of Mining and Geology, Belgrade, Serbia
Ferrite nanoparticles with different amount of cobalt were synthesized and
characterized using scanning electron microscopy (SEM) and X-ray powder diffraction
(XRPD). This work describes a new type of modified glassy carbon paste electrode based on
different Co-ferrites. The electrode was used for the determination of nanomolar level of
copper ions in natural waters using differential pulse anodic stripping voltammetry, DPASV.
A significant increase in current was achieved at the modified electrode in comparison with
the bare glassy carbon paste electrode. Electrochemical parameters such as percentage of
modifier, accumulation time and potential, pH and the optimized amount of cobalt in the
ferrites were determined. The best voltammetric response was observed for Co0.5Fe0.5Fe2O4
when percentage of modifier was 3 %, pH of supporting electrolyte acetate buffer 4.5,
deposition potential -0.3 V and deposition time 4 min. Influence of possible interferences
were determined. Thus prepared electrode displays selective detection toward copper ions,
detection limit of 44 nM and it was successfully applied for the determination of copper ions
in water samples.
105 Electrochemical behavior of acid activated clays
Tihana Mudrinić1, Zorica Mojović1, Aleksandra Milutinović-Nikolić1, Davor Lončarević1,
Božana Čolović2, Vukoman Jokanović2, Dušan Jovanović1
1
University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Center of
Catalysis and Chemical Engineering, Belgrade, Serbia
2
University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia
Smectites are phylosillicates of 2:1 type, meaning that octahedral sheet is sandwiched
between two tetrahedral sheets. Due to isomorphous substitutions (Al3+ or Fe3+ for tetrahedral
Si4+ and Mg2+, Fe2+ or Fe3+ for octahedral Al3+) these sheets have resulting negative charge.
Hydrated cations in interlayer region neutralize negative charge. Acid activation of clays
consists of mixing clay with acid solution. During acid treatment of clay interlayer cations are
replaced by H+ ions what is followed by dissolution of structural cations. The extent of acid
activation can be controlled by several factors: the concentration of acid, the ratio between
clay and acid solution, temperature and duration of contact between acid and clay.
In this paper is to investigate acid activation of smectite under very mild conditions. The
purpose of this activation is exposing of present Fe2+/Fe3+ ions to the environment and
subsequent investigation of obtained material as an electrode material. The obtained materials
were characterized by XRD and FTIR technique.
According to X-ray diffraction patterns smectite is the main constituent of the
investigated clay. The obtained basal spacing d001 =1.52 indicates that Ca2+ is the main
exchangeable cation, defining raw clay as Ca-bentonite. The XRD analysis confirmed that
conditions applied for acid activation were mild enough not to disturbe crystal structure of
smectite. The lines corresponding to smectite (001 and 060) are present at sample treated with
the highest used concentration although in lower intensity indicating that dissolution of clay
mineral was partial as intended.
The three bending vibrations of hydroxyl groups associated with Al3+, Fe2+ and Mg2+
( 915 cm−1, 875 cm−1 and 848 cm−1) were present in the FTIR spectra of starting and acid
activated samples confirming that acid activation did not completely removed iron ions from
smectite framework.
The acid activated clay samples were tested as electrode materials in acidic electrolyte,
0.1 M H2SO4. Aside from current rise at potential range limits due to hydrogen and oxygen
evolution, presented CV’s have only one feature at potential around 0.4 V. This peak is
ascribed to Fe3+/Fe2+ oxidation/reduction process. The current maxima are obtained for
samples treated with 1 M and 4.5 M HCl. The observed potential for oxido-reduction for
Fe3+/Fe2+ couple are lower than the standard potential for aqueous Fe3+/Fe2+ couple (+0.77 V
vs SHE). The reduction potential is lower for structural Fe3+ than for solution Fe3+. The shift
in reduction potential observed for different samples is driven by change of the ratio of Fe(II)
to Fe(III) species. The Fe3+/Fe2+ ratio can significantly influence the application of material as
catalyst. The acid activation provides an easy way to modify clay to desired effect.
106 Magnetic properties of ultrasmall iron-oxide nanoparticles
Dušan Milivojević1, Branka Babić-Stojić1, Vukoman Jokanović1, Zvonko Jagličić2,
Darko Makovec3, Nataša Jović1
1
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
2
Institute of Mathematics, Physics and Mechanics, Ljubljana, Slovenia
3
Department for Materials Synthesis, Jožef Stefan Institute, Ljubljana, Slovenia
Structural and magnetic properties of ultrasmall magnetic nanoparticles consisting of
inorganic iron oxide core and organic ester shell, dispersed in an organic fluid, synthesized via polyol
route were investigated. The structure analysis shows that nanoparticles are crystalline, less then 3 nm
in size, mutually clearly separated. The magnetic properties are in accordance with the size of the
nanoparticles and do not indicate interparticle interactions. The particles show pure superparamagnetic
behavior with very low blocking temperature. ZFCFC bifurcation and ac susceptibility peaks are at
temperatures TB < 12 K. The properties of fluid were compared with dried powder sample. Drying of
fluid brings about interactions between the magnetic nanoparticles that considerably affect spin
dynamics of the particles. The surface of nanoparticles has a significant influence on their behavior.
The Mössbauer parameters indicate existence of γ-Fe2O3 core and non-stoichiometric surface layer.
Magnetic field dependent magnetization analysis suggests smaller apparent size of the particles d0=
0.56 nm. High magnetic anisotropy due to surface layer anisotropy was measured to be of the order
106 erg/cm3 that is two orders of magnitude higher than that in bulk material.
107 List of authors and coauthors: 1.
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Aleksić I. .....................................83 Aleksić M. ...................................81 Aleksić V. .....................................65 Andrić Lj. .....................................23, 44, 56 Anđić Z. .......................................28 Antonijević Đ. ..............................73 Atanasijević D. ............................104 Babić B. ........................................89, 95 Babić Stojić B. ..............................107 Babić-­‐Ivančić V. ...........................15, 85, 86 Bajac B. ........................................103 Bajat J. ..........................................29 Bajić N. ..........................................32 Bajkin B. .........................................71 Barac R. .........................................79, 80 Baraković A. ..................................24, 54 Baraković D. ..................................53, 54 Bartulović Z. ..................................56 Bibić N. ..........................................97, 98 Blagojević D. ..................................71 Bobkov A. .......................................55 Borka D. .........................................35 Bošković I. ......................................19 Božić D. ..........................................104 Branković G. ...................................94 Cvejić Ž. ..........................................103 Čebela M. .......................................87, 88, 89, 91, 93 Čolović B. .......................................34, 60, 73, 106 Ćetenović B. ...................................69, 70 Ćirić Marjanović G. .........................102 Devčerski A. ....................................90 Dojčinović B. ...................................61 Došen A. .........................................89 Ducman V. ......................................57 Dugić P. ..........................................65 Dutour Sikirić M. ............................33, 101 Đeri A. ............................................74, 75, 76, 77, 78 Đorđević Lj. ....................................81 Đurđić E. .........................................103 Gašić J. ............................................79, 80 Gojić M. ..........................................18 Grbić B. ...........................................64 Hercigonja R. ..................................87, 102 Hinić B. ...........................................48 Husagić R. .......................................52 Ilić S. ...............................................87, 88, 91, 93 108 47.
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109 Isaković H. .......................................54 Jagličić Z. .........................................107 Jakimovska A. ..................................67 Janković O. .......................................77 Jenko M. ..........................................60, 82 Jokanovic V. .....................................14, 34, 37, 59, 60, 66, 69, 70, 71, 72, 81, 106 Jokanović B. .....................................59 Jokić B. .............................................99 Jokić M. ............................................29 Jordanov D. ......................................84, 92 Josipović R. .......................................74, 75, 76, 77, 78 Jotanović M. .....................................63 Jovanović D. .....................................106 Jović M. ............................................61 Jović N. .............................................107 Jurašin D. ..........................................100, 101 Kamberović Ž. ...................................28 Karađžić I. .........................................37 Kisić D. ..............................................96 Kljajević Lj. ........................................92 Knežević N. .......................................74, 75, 76, 77, 78 Kojić Ž. ..............................................74, 75 Kontrec J. .........................................86 Korać M. ..........................................28 Kosec B..............................................18 Kožuh S. ...........................................18 Krgović M. ........................................19 Krstić J. .............................................61 Kusigerski V. ....................................92 Kuveždić H. .......................................86 Lazić G. ............................................25, 42, 43 Lončarević D. ..................................106 Lopičić S. .........................................83 Luković J. .........................................93, 94, 95 Ljubić O. ..........................................50 Magić M. .........................................72 Majstorović J. ..................................90 Makarić S. .......................................100 Makovec D. .....................................107 Maksimović V. .................................91 Malešević J. .....................................47 Manojlović D. ..................................61, 105 Morasi Piperčić S. ...........................100 Martinović S. ...................................26 Markićević N. .................................102 Marković D. ....................................37, 69, 70, 71, 72 Matović B. ......................................84, 87, 88, 89, 90, 91, 92, 94, 95 Mićić V. ...........................................62, 63, 65 Milenković N. .................................57 Milivojević D. .................................36, 107 97. Milovanović B. ...............................84 98. Milutinović Nikolić A. ....................106 99. Minović T. ......................................93 100. Mirković M. .................................87, 88, 89, 93 101. Mitić A. ........................................79, 80 102. Mojović Z. ...................................106 103. Mudrinić T. ..................................106 104. Najman S. .....................................81 105. Nakić N. .......................................101 106. Nasov I. ........................................16, 67 107. Nedeljkov V. .................................83 108. Nedić Vasiljević B. ........................88 109. Nenadović M. ...............................96, 99 110. Nešić J. ..........................................61 111. Nikolić A. ......................................105 112. Nikolić B. ......................................22 113. Nikolić M. .....................................79, 80 114. Novak S. .......................................100 115. Novaković M. ...............................97, 98 116. Omerašević M. .............................87, 88, 89, 91 117. Pantić J. ........................................93, 94, 95 118. Pašti I. ..........................................95 119. Pavlović M. ..................................29, 44 120. Pejović B. .....................................62, 63 121. Perić T. ........................................71 122. Petković M. .................................65 123. Petrov M. ....................................56 124. Petrović B. ...................................71 125. Petrović Đ. ...................................71 126. Petrović M. ..................................38 127. Petrović V. ...................................40, 58 128. Petrović Z. ...................................63, 65 129. Popović J. ....................................79, 80 130. Popović M. ..................................97, 98 131. Pošarac Marković M. ..................90 132. Potočnik J. ...................................99 133. Prekajski M. .................................73, 94, 95 134. Primožić I. ...................................100 135. Prostran M. ..................................83 136. Radenković G. ..............................79, 80 137. Radić N. .......................................31, 64 138. Radman Kuzmanović I. ................74, 75, 76, 77, 78 139. Radoičić M. ..................................73 140. Radosavljević Mihajlović A. ..........88 141. Raić K. ..........................................104 142. Rakić S. ........................................103 143. Rakočević Z. .................................96, 99 144. Ranogajec J. .................................57 145. Riđošić M. ....................................29 146. Roglić G. .......................................61 110 147. Rosić M. .......................................84, 89, 92, 93 148. Rudić O. .......................................57 149. Rudolf R. .....................................17, 59 150. Ružić J. ........................................104 151. Selmani A. ...................................101 152. Simendić B. ..................................58 153. Simić S. ........................................65 154. Spasić S. .......................................83 155. Spasojević V. ................................92 156. Srdić V. ........................................103 157. Stambolić A. .................................82 158. Stanković D. .................................105 159. Stanojević M. ................................83 160. Stašić J. ........................................104 161. Stević D. .......................................46, 47 162. Stojadinović S. ..............................64 163. Stojanović D. ................................96 164. Stojiljković M. ...............................92 165. Stojmenović M. .............................94, 95 166. Šaponjić A. ....................................91 167. Šehić Dž. .......................................68 168. Šerić B ...........................................85 169. Šimunović D. .................................86 170. Škrivanj S. .....................................105 171. Šljukić B. .......................................102 172. Špiljak B. .......................................51 173. Tadić N. .........................................64 174. Tomić M. .......................................29, 62, 63 175. Trajkovska Petkovska A. ...............16, 30, 67 176. Tripković Đ. ...................................103 177. Vasilić R. ........................................64 178. Vasiljević P. ...................................81 179. Veselinović V. ...............................74, 75 180. Videnović N. .................................49 181. Vilotijević M. ................................59, 60 182. Vlahović M. ..................................27 183. Volkov Husović T. .........................21, 44, 90 184. Vučetić M. ....................................45 185. Vučetić N. .....................................45 186. Vučetić S. ......................................57 187. Vučetić V. ......................................45, 47 188. Vučić V. .........................................37 189. Vujačić V. ......................................22 190. Vukčević M. ..................................19 191. Vukmirović J. .................................103 192. Vuković A. .....................................69, 70 193. Vulić P. ..........................................61, 105 194. Xiong X-­‐Y. ......................................55 195. Zec S. .............................................91 196. Zhang K. ........................................98 111 197. Žabar Popović A. ...........................81 198. Živković S. .....................................39, 79, 80 112 SECOND REGIONAL
ROUND TABLE:
REFRACTORY,
PROCESS INDUSTRY
AND NANOTECHNOLOGY
Rosov pin 2014
CENTER FOR INDUSTRIAL AND TECHNOLOGICAL DEVELOPMENT ”ANDREVLJE”,
FRUŠKA GORA, SERBIA, OCTOBER 23-24, 2014
“ROSOV PIN 2014 focuses on connecting
different types of nanotechnology with
conventional technologies in refractory and
process industry. Nanotechnologies are not
only present in modern high tech
technology, but also in conventional
technology applied in the process industry
and refractory, giving the materials a
completely new mechanical and corrosion
properties.”
ENGENEERING ACADEMY
OF SERBIA
113 VINČA INSTITUTE
OF NUCLEAR SCIENCES
Organised by:
> Vinča Institute of Nuclear Sciences,
Belgrade
> Engineering Academy of Serbia,
Belgrade
> Lafarge BFC d.o.o. Beočin
> REAL S d.o.o. Beograd