1. No category

Hydrodynamik + kolloidkemi
= nya cellulosabaserade produkter
Håkansson K.M.O., Kvick M., Lundell F.,
Fall B.A., Prahl Wittberg, L., Wågberg, L. and Söderberg D
Januari 2015
WWSC is a joint research center at KTH and Chalmers
Clothes from wood
? kids.britannica.com wikipedia.org 2/19 Viscose or Rayon
Grinding Dissolving Cellulose I Polymer Cellulose II Spinning 3/19 Aral Sea
Aral Sea 1960 www.google.com/maps Peak CoGon? 4/23 Fibre properties
Black spruce wood fibre
Material properIes 4
Page, D. H. & el Hosseiny, F. J. Pulp. Paper. Sci 99–100 (1983) Specific Strength [MPa m3/kg]
10
The fibre properIes are highly dependent on the fibril orientaIon First Carbon Fibre
Crystalline cellulose
Aramid
S−glass
E−glass
3
10
o
32
39o
Viscose
Cotton
46o
Coir
2
1o
22o
Ramie
10
Spectra
Kevlar
Polypropylene
Nylon
Aluminium
Steel
HDPE
0
10
1
2
10
10
Specific Modulus [GPa m3/kg]
Eichhorn et al., J Mater Sci (2001) Eichhorn et al., J Mater Sci (2009) 5/11 Cellulose nanofibrils, CNF
AFM image of CNF 1 μm Courtesy of A. Fall and G. Nyström Gel Locked Dispersion Freely moving 3 g/l ≈ 0.3 % by weight 6/19 Sp ecific Strength [MPa cm 3 /g]
Wet spinning of cellulose nanofibrils
E−glass
3
10
Cotton
Viscose
46o
2
10
42o
32o
Fibril
1o
22o
Cellulose II filament
Cordenka 700 filament
26o
32o
Wood chip
CNF paper
CNF paper, Henriksson et al. (2008)
CNF, Walther et al. (2011)
CNF, Iwamoto et al. (2011)
CNF, Sehaqui et al. (2012)
1
10
Sp ecific Modulus [GPa cm 3 /g]
2
10
Walther el al. (2011) Adv. Mater. 7/19 Flow focusing – popular in micro-fluidics
b)
Accelerated flow is used in order to align cellulose nanofibrils x
y
z
Q2 /2
Q1
h = 1 mm Q2 /2
h H2O h = 1 mm H2O + Ink H2O 8/19 Filament Manufacturing Process
Nano-­‐cellulose liquid dispersion y
NaCl NaCl z
Gel thread H2O 9/23 Process concept
10/19 Process concept
b)
x
y
Nano Cellulose z
Ions Q2 /2
Q1
h = 1 mm Q2 /2
Ions h 1
11/19 SEM Images of Dried Filaments
30 μm 3 μm 1 μm 20 μm 12/23 PETRA III, Synchrotron in Hamburg
13/19 X-ray Scattering
Wide Angle X-­‐ray ScaGering Detectable scales ~ Å 2-­‐9 m 10-­‐50 cm 2θ
€
X-­‐ray beam from the synchrotron €
d=
λ
2sin θ
Small Angle X-­‐ray ScaGering Detectable scales ~ 1-­‐500 nm 14/19 Orientation from X-ray data
The order parameter, S: ϕ
S = P2 (cosϕ) =
3 2
1
cos ϕ −
2
2
In this case: €
π
€
Intensity, I(ϕ)
40
€
30
S=
$3 2
1'
I(
ϕ
)
cos
ϕ
−
&
) sin ϕdϕ
∫ %2
(
2
0
Random orientaIon Aligned 20
10
0
0
100
200
300
Azimuthal angle, ϕ
S = 0 S = 1 15/19 Order parameter
Extensional Flow and Fibril Orientation
0.8
AcceleraIon 0.6
0.4
Shear Brownian diffusion 0.2
0
−0.2
−2
DeceleraIon 0
2
4
6
8
10
Downstream p osition, z/h
12
14
16/19 Controllable properties
Figure 5.3. Properties of common filament materials.
(a,b) Overview and close-up of specific ultimate strength versus specific Young’s modulus for a number of materials, re-
17/19 Thin filament with a knot
H2O pH 2 Order parameter, S
Cellulose nanofibrils 0.5
0.4
0.3
0.2
SAXS
Diffusion
S = 0.36
POM
0.1
0
0
5
10
15
20
25
Downstream p osition, z/h
30
18/19 Conductive filament
40 % Carbon nanotubes 60 % Cellulose nanofibrils ConducIvity = 200 S/cm Hamedi et. al. (2014) ACS Nano 19/19 Extensible filament
20/19 Thank You and Thanks to:
Kungliga Tekniska Högskolan (KTH) Chalmers Tekniska Högskola (CTH) InnvenIa AB Deutsches Elektronen-­‐Synchrotron (DESY) Wallenberg Wood Science Center (WWSC) Linné FLOW Centre KTH Mechanics: Adj. Prof. D. Söderberg Ass. Prof. F. Lundell PhD. L. Prahl WiGberg Lic. M. Kvick DESY Hamburg: PhD. S. Yu PhD. G. Santoro PhD. S. V. Roth PhD. C. Krywka KTH Fibre & Polymer Technology: Prof. L. Wågberg Prof. L. Berglund PhD. A. Fall PhD. M. Hamedi CTH Polymeric Materials & Composites: Prof. M. Rigdahl InnvenIa AB: Prof. T. Lindström PhD. C. Aulin 21