Upload
others
View
18
Download
2
Embed Size (px)
Citation preview
Carbon Fibers, Multi-functional Textile Fibers,
Meso-porous Carbon
Opportunities for lignin and cellulose nano crystals
(based on examples of polymer/carbon nanotube studies)
Satish Kumar
School of Materials Science and Engineering
Georgia Institute of Technology
Atlanta, GA 30332-0295
1
Institute of Paper Science and Technology April 18, 2013
Carbon Fibers
2
1960 – Start of Carbon Fiber Research in Japan, UK, and USA.
Carbon Fiber market is growing at about 10 - 12% per year.
Carbon fibers have been produced from Rayon, poly(acrylonitrile) (PAN), and
from petroleum pitch.
Early carbon fibers were produced from Rayon, and these rayon based carbon
fibers are no longer commercially produced.
Currently carbon fibers are predominantly made from PAN.
PAN based carbon fiber tensile strength: 3 to 6 GPa, Tensile modulus: 200 to
500 GPa.
M. L. Minus and S. Kumar, JOM, 57, 52-58 (2005)
Lignin based Carbon Fibers
3
• Research driven by the desire to produce a low cost carbon fiber.
• Tensile strength in the range of 0.5 to 1 GPa and tensile modulus in the range of
35 to 40 GPa demonstrated for the lignin based carbon fibers. (Clemson
University, ORNL, American Chemical Society, New Orleans, April 2013).
• Due to high degree of chemical crosslinking, lignin based carbon fibers exhibit
very little or no molecular orientation, thus resulting in relatively low modulus.
• Carbon fibers are also being made from the PAN/ lignin blend fibers (DOE project
at Zoltek).
• For automotive application, there is a need to bring the carbon fiber cost down to
about $5/lb (DOE target). At this cost, carbon fiber with a tensile strength of about
2 GPa and tensile modulus of about 175 GPa would be sufficient.
Fiber and Carbon Fiber Processing Facilities at Georgia Tech
4
• Single filament, single component and bi-component melt, solution, and gel
spinning. Scale - about 100 ml polymer solution or about 100 g polymer melt can
be spun on these lines.
• 100 filament single component and bi-component dry-jet solution and gel
spinning and multi-zone drawing line. Polymer solutions (at the scale of 1 to 6
liters) can be spun on this line. Five, 100 filament tows can be combined to
make a 500 multifilament tow. This facility is in class 1000 clean-room.
• About 70 ft long continuous carbonization line with multi-zone stabilization and
multi-zone carbonization capability. This line is also located in class 1000 clean-
room. Continuous carbonization of 100 to 6000 filaments has been
demonstrated on this line.
• Well equipped fiber characterization and testing facility.
n
N
O O
N
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 0.5 1 1.5 2 2.5 3
Strain (%)
Str
es
s (
GP
a)
PBO
PBO/SWNT(90/10)PBO
PET/CNF
S Kumar, TD Dang, FE Arnold, AR Bhattacharyya, BG Min, XF Zhang, RA Vaia, C Park, WW Adams, RH Hauge, RE Smalley,
S Ramesh, PA Willis, Macromolecules, 35(24), 9039 (2002).
H Ma, J Zeng, ML Realff, S Kumar, DA Schiraldi, Composites Science and Technology, 63, 1617 (2003).
SWNT
5
Raman Spectroscopic evidence of load transfer from matrix to CNT
- PVA/SWNT films
• Well dispersed and exfoliated SWNTs in PVA.
• Significant increase in tensile properties.
Stress-strain curves
2566
2568
2570
2572
2574
2576
2578
2580
2582
0 10 20 30 40 50
Strain (%)
D*
ban
d p
eak p
osit
ion
(cm
-1)
Raman D* band shift with strain
300 400 500 600 700 800 900
Wavelength (nm)
Ab
so
rba
nc
e (
a. u
)
a
b
c
d
UV-VIS Spectra
Raman D* band shift with strain
(a) PVP/SDS/SWNT aqueous dispersion
(b) PVA/PVP/SDS/SWNT film (1 wt% SWNT)
(c) PVA/PVP/SDS/SWNT film (5 wt%)
(d) PVA/SWNT film (1 wt%)
XF Zhang, T Liu, TV Sreekumar, S Kumar, VC Moore, RH Hauge, RE Smalley, Nano Lett, 3(9), 1285 (2003). 6
Individual CNT in PAN matrix
PAN/CNT – early developments
At 10% CNT, 50 times increase in modulus at 140 oC, and 40 oC increase in Tg
5 nm
TV Sreekumar, T Liu, BG Min, H Guo, S Kumar, RH Hauge, RE Smalley, Advanced Materials, 16(1), 58 (2004). 7
PAN/SWNT (60/40) Film
– Electrical conductivity (~104 S/m) – comparable to
electrically conducting polymers such as polythiophene,
polypyrrole, and polyaniline.
– Tensile strength (100 MPa) and modulus (11 GPa) higher
than that of SWNT bucky paper or the polymer, and
comparable to those of the engineering thermoplastics
– Films exhibit high degree of dimensional stability (CTE <2
ppm/oC)
– Polymer molecular motion above glass transition
temperature is dramatically suppressed.
– Low density (~1 g/cm3)
– Thermally stable and exhibits Chemical resistance
0.0
0.1
0.2
0.3
0.4
0.5
0.6
30 50 70 90 110 130 150 170
Temperature (oC)
tanδ
PAN/SWNT (60/40) film
Control PAN film
H Guo, TV Sreekumar, T Liu, M Minus, S Kumar, Polymer, 46, (2005) 3001-3005
-2
-1
0
1
2
0 20 40 60 80 100 120 140
Temperature ( 0C)
Dim
ensi
on
ch
ang
e (%
) Control PAN film
PAN/SWNT (60/40) film
CNT
PAN
molecules
8
GW Lee, S Jagannathan, HG Chae, ML Minus, S Kumar, Polymer, 49, 1831 (2008)
Drawn fiber
before heat
treatment
Fiber
after heat
treatment (170 oC)
PP
PP/CNT (1%)
Polypropylene/CNT
Near Tm, PP fiber without CNT begins to
loose orientation, while PP with CNT
retains orientation.
Shrinkage in PP/CNT was less than
20% of the shrinkage observed in PP
without CNT
9
Polypropylene/CNT - Transcrystallization Polypropylene crystallization on CNT
(a)
150m
(b)
150m
(a)
150m
(b)
150m
(b)
150m
S Zhang, ML Minus, S Kumar, LB Zhu, CP Wong, Polymer, 49, 1356-1364 (2008)
50µm
(a)
3 µm
(b)
(c)(d)
50µm
(a)
50µm
(a)
3 µm
(b)
3 µm
(b)
(c)(d)
CNT fiber
10
Interphase – Comparison between composite and nanocomposite
For creating interphase, a nano material can be 25000 times more effective than a
conventional reinforcement such as carbon fiber.
Carbon Nanotubes act as a template for polymer orientation and nucleating agent for
polymer crystallization.
Interphase
Bulk polymer
Carbon
fiber CNT
Diameter 5 µm 1 nm
Interphase
layer thickness 5 nm 5 nm
Interphase/filler
volume ratio 0.004/1 99/1
11
12
Rheology
At low shear rate, there is increased resistance to flow due to network formation
between CNTs. At high shear rate, resistance to flow decreases as CNTs and
polymer molecules align along the flow direction.
PAN/CNT
PAN
Gel spun PAN/SWNT (99/1) - HRTEM
13
Highly aligned and ordered PAN molecules
are observed in PAN/CNT fibers
HG Chae, ML Minus, S Kumar, Polymer, 47, 3494 – 3504 (2006).
Gel spun PAN/SWNT (99/1) – stabilization and carbonization
PAN PAN/SWNT (99/1)
Stabilized
Carbonized
14 HG Chae, ML Minus, A Rasheed, S Kumar, Polymer, 48(13), 3781 (2007).
Volume fraction of fibrils in the
carbonized PAN/CNT fibers is an
order of magnitude higher than
the volume fraction of SWNTs in
this fiber.
This is a result of PAN templating
on CNT
15
Carbonized gel spun PAN/SWNT (99/1) – TEM and Raman spectroscopy
PAN/CNT based carbon fibers show
well developed graphitic regions.
Graphitic regions are not observed
in PAN based carbon fibers
processed under comparable
conditions.
Presence of graphitic regions has
also been confirmed by Raman
spectroscopic studies.
PAN PAN/SWNT
HG Chae, ML Minus, A Rasheed, S Kumar, Polymer, 48(13), 3781 (2007).
Fiber drawing system
Unwinding stand Drawing stands
Water rinse
stand
Drying
stand
Take-up
winder
17
21
PEK/CNT Fibers
• Axial electrical conductivity 240 S/m
• Thermal conductivity as high as 17 W/m/K
• Density ~1.3 g/cm3
Thermally and electrically conducting polymeric fibers
R Jain, YH Choi, Y Liu, ML Minus, HG Chae, JB Baek, S Kumar, Polymer, 51, 3940-3947 (2010)
J Moon, K Weaver, B Feng, HG Chae, S Kumar, JB Baek, GP Peterson, Review of Scientific Instruments, 83, 016103 (2012)
22
0.E+0
1.E-2
2.E-2
3.E-2
4.E-2
5.E-2
6.E-2
7.E-2
0.1 1 10 100 1000
Pore Width (nm)
Incre
men
tal p
ore
vo
lum
e(c
m3/g
)
700 deg C
800 deg C
900 deg C
757 ± 23 m2/g
(BET)
1741 ± 35 m2/g
(BET)1699 ± 34 m2/g
(BET)
0
50
100
150
200
250
300
350
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Sp
ec
ific
Ca
pa
cit
an
ce
(F
/g)
Cycles
PAN/CNT (80/20)
CNT
PAN/CNT based supercapacitor electrodes
PAN/CNT based capacitors perform better
than CNT based capacitors, even after
10,000 charge/discharge cycles
S Jagannathan, T Liu, S Kumar, Composites Science and Technology, 70, 593 (2010).
Pore size control in the range of 1 to 5 nm
23
Future Directions: Functional Fibers
Using this approach functional fibers can also be made using other nano materials
– introducing corresponding functionality in the sheath or in the core. A different
nano material and hence a different functionality can be introduced in each
component. Fibers, with three or more components and hence correspondingly
more functionalities, can be made.
Lignin and cellulose nano crystals (CNCs) can be incorporated in either part of the
fiber.
A-T Chien et al., SAMPE Technical Conference Proceedings, Charleston SC, October 22-25, 2012.
Opportunities for lignin and cellulose nano crystals (CNC) for processing
structural carbon fibers, multifunctional textile fibers, and meso-porous carbon
24
Lignin/ synthetic polymer/CNT fibers
CNC/synthetic polymer fibers in combination with other nano materials
0
50
100
150
200
250
300
350
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Sp
ec
ific
Ca
pa
cit
an
ce
(F
/g)
Cycles
PAN/CNT (80/20)
CNT
Cost effective, increased functionality, and enhanced Green Foot Print
25
Contributors
• Current Group – Dr. Han Gi Chae
– Dr. Kishor Gupta
– Dr. Yaodong Liu
– Dr. Prabhakar Gulgunje
– Dr. M. G. Kamath
– Dr. Sushanta Ghoshal
– An-Ting Chien
– Brad Newcomb
– Kevin Lyons
– Ken McDonald
– Joshua Gomberg
– Andrew Gorman
– Clive Liu
– Amir Davijani
• DARPA
• AFOSR
• IPST
• ONR
• NSF
• NIST
• AFRL
• Boeing
• Rice University (Smalley, Tour)
• CNI, Unidym, CCNI
• Applied Sciences Inc
• Tao Liu – FSU
• Ioannis Chasiotis – UIUC
• Jong-Beom Baek – UNIST
• B. Feng
• G. P. “Bud” Peterson
• Art Ragauskas
• Previous group members (over 60)