manufacturing and applications of carbon nanotube sheet · electrical properties. the transfer of...

Manufacturing and Applications of Carbon Nanotube Sheet

RACHIT MALIK1, NOE ALVAREZ

1, MARK HAASE

1, BRAD RUFF

2, YI SONG

2, BOLAJI

SUBERU2, DUKE SHEREEN

3, DAVID MAST

3, ANDREW GILPIN

4, MARK SCHULZ

2,

VESSELIN SHANOV1

1,4

School of Energy, Environment, Biological and Medical Engineering, 2School of Dynamic Systems,

3Department of Physics,

Nanoworld Laboratories, University of Cincinnati,

Cincinnati, OH 45221 USA.

http://www.min.uc.edu/nanoworldsmart

Abstract: - Individual Carbon nanotubes (CNTs) are known to have exceptional mechanical and

electrical properties. The transfer of these extraordinary qualities into CNT products, without

compromising on performance, remains a challenge. This paper presents an insight in the

manufacturing of CNT sheets, the use of plasma for functionalization of nanotubes and their

applications. Sheets of multi-walled carbon nanotubes (MWNTs) drawn from spin-able CNT arrays

have been developed. The sheets comprise nanotubes aligned in the pulling direction as shown via

Scanning electron Microscope (SEM) characterization. The alignment of the nanotubes imparts

anisotropic properties to the sheet and leads to a significantly higher Electromagnetic Interference

(EMI) shielding effectiveness. Surface modification of aligned MWNT sheets was carried out via an

atmospheric pressure plasma jet during the post-treatment process. Helium/Oxygen plasma was

utilized to produce carboxyl (-COO-) functionality on the surface of the nanotubes. X-Ray

Photoelectron Spectroscopy (XPS) confirms the presence of functional groups on the nanotube

surface. The sheet was further characterized using Raman Spectroscopy, Fourier Transform Infrared

(FTIR) Spectroscopy and Contact Angle testing. Composite laminates made from functionalized CNT

sheets in a polyvinyl alcohol (PVA) matrix demonstrate more than 100% increase in tensile strength

over those made with pristine sheets used as reinforcement material.

Key-Words: - Carbon nanotube, sheet, plasma, XPS, EMI shielding, composites.

1. Introduction Carbon Nanotubes (CNTs) have come a long way

since their discovery in 1991 1. The arc discharge

evaporation method initially used to synthesize

nanotubes has given way to large scale production

by chemical vapor deposition 2. The individual

nanoscale tubules of carbon have exceptional

mechanical strength, high Young’s modulus, 3 and

superior specific conductivities 4. During growth,

depending on the conditions in which they are

formed, nanotubes assemble either as double-

walled/multi-walled co-axial tubules

(DWNTs/MWNTs) or as bundles (ropes) consisting

of individual tubes (single-walled nanotubes,

SWNTs) packed in two-dimensional triangular

lattices 5.

Carbon nanotubes have been extensively

employed in many applications ranging from

electrodes for fuel cells 6, batteries

7, super-

capacitors 8, solar cells

9, as substrates for biological

cell growth 10, 11

and materials for EMI shielding 12

.

Transparent and conducting thin films for touch

screens 13, 14

, polarized light emitters 15

, loud

speakers 16

, and high performance energy storage

devices 17

have been demonstrated. Individual CNTs

have demonstrated exceptional mechanical strength

and superior electrical conductivities, but

extrapolating these properties to macroscopic

structures of carbon nanotubes has been a challenge.

The CNT dispersion approach is widely used in

solution processing, melt processing, electro-

spinning, and coagulation spinning of Polymer/CNT

composites 18, 19

. CNTs typically have to be purified

by washing in acids before they can be deposited as

paper-like films or in threads. The nanotubes thus

produced typically demonstrate poor mechanical

properties and are randomly oriented. The

dispersion of long CNTs is hindered by their

Recent Advances in Circuits, Communications and Signal Processing

ISBN: 978-1-61804-164-7 327

entanglement and aggregation, and the CNTs are

often presented with a low fraction (<10 wt. %) and

random orientation resulting in relatively low

strength of the final materials 20, 21

. Alternatively,

gas phase catalytic decomposition of ethylene at

high temperature in the presence of floating catalyst

iron particles produces a cloud of CNTs 22

which are

then withdrawn continuously to produce yarns and

sheets. This method has gained popularity for mass

production at low cost but, the nanotubes in these

materials are also randomly oriented and contain

significant amounts of catalyst particles as

impurities. Pure and dense bucky-papers have also

been produced by simply pushing down in one

direction, the nanotubes grown in the form of an

array on catalyst coated substrates. 23

Contrary to the above mentioned

techniques, the process of dry-spinning multi-walled

carbon nanotubes from arrays grown by Chemical

Vapor Deposition (CVD) 15

, presents a more flexible

approach. Herein, we report the development of a

dense, lightweight, robust and electrically

conductive sheet material comprising of oriented

multi-walled carbon nanotubes. This material

inherits the anisotropic characteristics of the

nanotubes and has found two potential applications

viz. as an effective, light-weight EMI shielding

material and as a strong reinforcement material in a

polymer composite.

2. Experimental Methods 2.1. CNT sheet preparation The CNT sheets were drawn from 0.5 mm tall

MWCNT arrays synthesized by a water-assisted

chemical vapor deposition (CVD) process 24-26

. The

setup used at UC to produce highly aligned CNT

sheet was built in-house and is described in detail in

a previous work 27

. It consists of a

polytetrafluoroethylene (PTFE) belt acting as a

substrate on which layer after layer of the MWNT

aerogel is collected. As the belt is rotated, the CNT

array can be moved perpendicular to the drawing

direction, in order to create a two dimensional sheet

of highly aligned CNTs.

The sheets are densified using volatile

organic solvents like acetone and ethanol. Figure 1A

shows a schematic of the sheet production along

with a picture of the machine. Figure 2 shows a

close-up optical image of CNT sheet revealing its

uniformity along with a SEM micrograph of the

sheet illustrating a good degree of alignment of the

CNTs within the sheet.

Figure 1. CNT sheet manufacturing process: A)

schematic illustration of the setup; B) CNT sheet

preparation from vertically aligned CNT array. 27

Figure 2. CNT sheet: (A) wound on a Teflon

substrate; (B) SEM image of the sheet showing the

degree of alignment of the CNT.

2.2. Atmospheric pressure plasma

functionalization Pristine CNT sheets were functionalized with

atmospheric pressure plasma produced from a

SurfxTM

Atomflo 400-D reactor comprising of

oxygen as the active gas and helium as the carrier

gas. This type of plasma system has been previously

employed to deposit glass coatings on aluminum 28

and other materials. The base unit is supplied with

an applicator with 25 mm in diameter active area

and an air cooled 300W RF generator performing at

27.12 MHz The RF atmospheric pressure plasma

source Atomflo 400D is shown in Figure 3. It

produces a plasma environment at low temperature

which preserves the CNT materials from damaging.

The plasma is formed by feeding He at a constant

flow rate of 30L/min and the flow rate of O2 (0.2 –

0.65 l/min) is adjusted as per the plasma power

desired. CNT sheets were treated for different time

intervals and with different plasma power to

estimate how plasma parameters affect the extent of

functionalization of the sheet surface.

Figure 3. Plasma system: (A) Surfx Atomflo 400-D

plasma controller; (B) plasma head 29

.


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2.3. Characterization 2.3.1. Raman Spectroscopy Raman spectra were obtained using Renishaw inVia

Raman Microscope with a 514 nm laser at 10%

power level. The rise in intensity of the D-band or

the disorder band peak in the spectra relative to the

G-band or the graphitic band of the nanotubes

reveals that the plasma creates defects in the

sidewall of the nanotubes. Figure 4 shows the

Raman spectra obtained for sheets functionalized

under plasma different conditions.

Figure 4. Raman spectra for untreated (control) and

treated CNT sheet samples.

The values of ID/IG ratios from the Raman

spectra of samples are presented in Table 1 and are

in accordance with data presented in other research

articles [75]. It is also revealed that the nanotubes

produced at UC are of high quality which has been

ascertained from the low ID/IG ratio for the untreated

nanotube sheet sample.

Table 1. ID/IG ratio from Raman Spectroscopy of

CNT sheet samples treated with He/O2 plasma for

different times and plasma power.

Plasma

Power (W)

Treatment time

(sec) ID/IG ratio

Untreated 0 0.72

100 30 1.00

140 30 1.02

60 1.17

90 1.20

180 30 1.18

It is observed that the plasma effectively

creates defects on the sidewalls of the nanotubes and

the ratio increases with increase in plasma power

and time of treatment. It is observed that the change

between 180W and 140W treatment is significantly

higher than that between 100W and 140W. A

similar observation can be made from the

comparison of time of treatment. A stark increase in

the ID/IG ratio is observed as the treatment time is

increased from 30s to 60s and a less insignificant

change seen between ID/IG ratios for 60s and 90s.

Therefore, high plasma power damages the

nanotubes more readily albeit creating more

functional groups but disturbing the CNT structure.

Secondly, longer time of treatment tends to the

creation of a larger number of defects but the rate of

defects does not increase linearly with time and

there is an upper limit to the extent of

functionalization of the exposed nanotubes.

Therefore, to achieve the desired functionalization

with simultaneously preserving the CNT structure, it

is necessary to have a short treatment time and

reduced (~100W-140W) plasma power. This

supposition is further supported via electrical

characterization of the CNT sheet before and after

plasma treatment as presented in Table 2.

Table 2. Effect of plasma treatment on the electrical

resistance of the CNT sheet.

Sample (Plasma

power,

Treatment time)

Resistance

before plasma

treatment

(ohms)

Resistance

after plasma

treatment

(ohms)

100W – 30sec 59.4 65.8

140W – 30sec 56.3 75.8

140W – 60sec 54.2 98.5

140W – 90sec 58.7 150.6

180W – 30sec 60.8 109.7

2.3.2 X – ray Photoelectron Spectroscopy XPS spectra were acquired using a Phi 5300 X-ray

Photoelectron Spectrometer with Mg K-alpha X-

rays at an accelerating voltage of 15.0 kV, and

charge compensation was provided by an electron

flood gun. XPS analysis shows increasing oxygen

concentration with increasing plasma power and

time of exposure, as summarized in Table 3.

Table 3. Elemental composition results from XPS

analysis of plasma treated CNT Sheet.

Sample C (%) O (%) N (%)

Untreated 95.9 3.8 0.3

100W – 30s 87.8 11.3 0.9

140W – 30s 85.0 13.8 0.9

140W – 60s 82.2 16.8 1.0

180W – 30s 85.0 14.1 1.3

In addition to the determination of atomic

composition, XPS analysis was also used to

determine the degree of oxidation of the carbon


ISBN: 978-1-61804-164-7 329

atoms which comprise the sample. Oxygen

incorporation into the nanotube backbone leads to

disruption of the π-conjugation of the backbone,

which resulted in an increase in the ID/IG ratio as

shown by the Raman analysis. Curve fits of plasma

treated (140W/60 seconds) and pristine CNT sheets

are shown in Figure 5.

Figure 5. High resolution XP spectra for CNT

sheets: (A) plasma functionalized; (B) pristine.

The spectra in Figure 5 have been shifted so

that their C-C peak occurs at 284.6 eV, an integrated

(Shirley) background was subtracted, and every

curve fit component peak utilized the same

asymmetric GL(30) peak shape and FWHM (Full

Width at Half Maximum). The plasma treated

sample (Figure 5 A) shows the formation of peaks

within the fitted curve which are attributed to –C=O,

-C-O-X and O=C-O-X functionalities, where X is

either a carbon or hydrogen atom. By comparing the

area percent of each component and the total

amount of oxygen present in the sample (Table 3),

X is postulated to be hydrogen, and therefore

carboxyl and hydroxyl functionalities predominate

over ether and ester functionalities on the nanotube

surface. The pristine nanotube sheet (Figure 5 B)

shows a much less pronounced shoulder at higher

binding energies; however the curve fit does

indicate that the pristine nanotubes have a small

amount of defects or functional group sites. The π-

π* shake-up satellite (290.67 eV) is not a functional

group, but it is instead evidence of conjugation

existing within the pristine nanotubes. The

conclusion from XPS analysis is that plasma

treatment has created -C-OH, –C=O, and O=C-OH

functionalities on the carbon nanotubes. This

conclusion is supported by data published by other

researchers who have functionalized CNTs with

plasma 30

.

2.3.3 Fourier Transform Infrared (FTIR)

Spectroscopy FTIR analysis of the sheet samples validates the

results from the XPS analysis and suggests that

indeed functionalization of the MWNTs has taken

place with primarily carboxyl (-COOH), hydroxyl (-

OH) and carbonyl (-C=O) groups being formed on

the surface of the nanotubes. The samples were

tested using Digilab Excalibur FTS 3000 FTIR

spectrophotometer. Figure 6 shows the results from

the FTIR analysis of the A) 100W plasma treated

sample for 30 seconds compared with that of B) the

control/pristine sheet sample. It can be seen that

there are two distinct features or peaks that are

observed for the plasma treated samples in the 1714

cm-1

and 1610-1650 cm-1

regions, these peaks can be

attributed to the C=O stretching and water adsorbed

on the surface respectively. The stretching around

the 1546 cm-1

is common for both functionalized

and un-functionalized samples and can be attributed

to C=C stretching of the CNT structure.

Figure 6. FTIR analysis: (A) 100W plasma treated

sample for 30 seconds; (B) untreated/pristine sheet.


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The adsorption of water or moisture from

the environment on the sheet surface (shown by

broad peak in the 3000-3500 cm-1

region) is critical

as it provides hydrogen atoms and the treatment of

the sheet with He-O2 plasma makes the sheet more

hydrophilic. A similar spectrum is also reported by

Wang et al 31

in their study of oxidative treatment of

MWNTs with dielectric barrier discharge plasma.

2.3.4 Contact Angle Testing The increase in the hydrophilicity as indicated by

the water adsorption in the FTIR analysis is

confirmed via Contact Angle testing. The contact

angle visualized by a drop of deionized (D.I.) water

was measured using Model 590 Rame-hart

instrument Contact Angle goniometer. Figure 7

shows images of the droplet of water on pristine and

plasma treated sheet.

Figure 7. Droplet of D.I. water: (A) on pristine; (B)

plasma treated CNT sheet.

The measured contact angle for the CNT sheet

drops from average 79.6o for the pristine sheet to

14.5o for the plasma treated samples, showing the

change from hydrophobic to hydrophilic nature of

the sheet. This change can be explained on the

premise that water droplet is now associated with

the CNT sheet through H-bonding with –OH and –

COOH groups on the nanotube surface which are

generated via the plasma treatment.

3. Applications of CNT Sheet 3.1. Electromagnetic Interference Shielding

An electromagnetic wave consists of mutually

perpendicular components of electric and magnetic

fields which are perpendicular to the direction of

propagation of the wave, as shown in the illustration

in Figure 8. The applied electric field on the surface

of an ideal conductor induces a current that causes

displacement of charge inside the conductor which

cancels the applied field inside, at which point the

current stops. Similarly, oscillating magnetic fields

generate Eddy currents that act to cancel the applied

magnetic field itself.

Figure 8. Illustration of the incident electromagnetic

(EM) wave channeled through the waveguide with

electric and magnetic field components.

The carbon nanotube sheet produced at UC

is a free standing, light-weight, robust and

electrically conductive material thereby making it a

perfect candidate for electromagnetic interference

(EMI) shielding. The nanotube alignment in the

sheet creates anisotropy in the conductivity and

when the CNT main axis aligns parallel to the

electric field component of the incident

electromagnetic radiation, a significantly higher

current is induced in the nanotubes. Therefore, a

higher shielding effectiveness is observed. This is

illustrated in Figure 9 and Table 4 showing the

results of shielding effectiveness from a 10GHz

incident wave.

Figure 9. Illustration of the effect of nanotube

orientation on the transmission of an electric field

through the sheet.


ISBN: 978-1-61804-164-7 331

Table 4. Effect of orientation of CNT with respect to

incident electrical field (E) on the shielding

effectiveness of an 80-layer thick CNT sheet.

Sample

Power

Transmitted

(dB)

Shielding

Effectiveness

(dB)

Air -22.1 0

CNT Sheet –

perpendicular

to E

-30.66 8.56

CNT Sheet-

parallel to E -49.12 27.02

The shielding measurements were made

using two separate waveguide systems; one was X-

band, 8.2 to 12.4 GHz and the other was KU-band,

12.4 to 18 GHz. The microwave signals were

generated by a Hewlett-Packard 8671B generator

which operates from 2 to 18 GHz. The signals were

fed via low loss coaxial cables to a directional

coupler (Krytar 4-20GHz, -6dB) connected to an

SMA to waveguide coupler, which in turn was

connected to a short section of straight waveguide.

The output part of the waveguide system was

identical to the input section but in reversed order:

straight waveguide section, waveguide to SMA

coupler connected to a Hewlett-Packard 437B

microwave power meter with 8485A power sensor

(50MHz-26.5GHz, 1microW- 100mW). The sample

was placed in an air gap (~3mm) between the input

and output straight waveguide sections. The input

directional coupler was connected so that we could

measure the amplitude of the signal that was

reflected from the waveguide-sample system (using

Hewlett-Packard 8485B power sensor, 100pW-10

microW, 50MHz-26.5GHz), while the power meter

allowed measurement of the amplitude of the

transmitted signal. Measurements were first made

without the sample (in air) and then made with the

sample so that the relative change in the transmitted

and reflected power was determined. The reflected

and transmitted signals were also measured using a

Tektronix 494P 10kHz-21GHz spectrum analyzer.

The effect of the frequency of the incident

EM wave on the shielding effectiveness of the sheet

was studied for the Ku (12.5-16 GHz) band of the

electromagnetic spectrum. Ku band is primarily used

for satellite communications, most notably for fixed

and broadcast services. The results of the

experiment are shown in Figure 10.

It is observed that the shielding

effectiveness of the nanotube sheet sample varies

with frequency with peak effectiveness being

observed at 16 GHz and the range lying between 25-

40 dB for CNT sheet samples with the nanotubes

oriented in the direction of the oscillation of the

electric field. These results demonstrate the ability

of the CNT sheet to be effectively used as an EMI

shielding material especially for applications where

weight of the material is a concern such as in

aerospace applications.

Figure 10. Effect of frequency of incident radiation

on the shielding effectiveness of the CNT sheet

(CNTs aligned parallel to electric field component

of incident wave).

3.2. Composites The effect of plasma functionalization of CNT

sheets on the mechanical properties of pre-pregs

made from CNT sheet was explored. Carbon

nanotube sheets densified with ethanol were used to

fabricate pre-pregs by a simple brush & paint-on

technique employing solution of polyvinyl alcohol

(PVA) in water.

In the first experiment, a 100-layer CNT

sheet sample with dimensions 0.25 inch by 6 inches

was manufactured and cut in half. One half of it was

plasma functionalized at 140W plasma power for 30

seconds and the other half was left pristine. These

sheets samples were then utilized to manufacture

pre-pregs with 10g/L PVA solution in water as

matrix material. Then the CNT sheet/PVA pre-pregs

were cured at 120°C for two hours in a hot press.

Tensile testing of these and other composite

materials has been carried out using Instron 5900

series testing instrument. The results of the test are

shown in Figure 11 for a high power plasma setting.

Prepregs with high power plasma treated

sheet samples had lower strength than those

containing pristine sheets. Data from the above

experiment is given in Table 5.


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0

20

40

60

80

100

120

140

160

180

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

Te

ns

ile

Str

en

gth

(M

Pa

)

Tensile Strain (%)

PVA/CNT sheet Composites

Pristine 1

Pristine 2

Pristine 3

Pristine 4

Plasma140W30s-1

Plasma140W30s-2

Plasma140W30s-3

Plasma140W30s-4

Functionalizedsamples

Figure 11. Stress-strain curves for PVA/CNT pre-

pregs with pristine and functionalized CNT sheets

using high power plasma.

Table 5. Mechanical properties of pristine and high

power plasma functionalized CNT PVA prepregs.

Sample type Mean

Young's

Modulus

(GPa)

Mean

Tensile

Strength

(MPa)

Pristine/Untreated sheet 11.6 116.7

Plasma Functionalized

(140W30s)

6.3 49.1

The decrease in Young’s modulus and

tensile strength can be attributed to the destructive

effect of the plasma treatment as is observed in the

increase of the ID/IG ratio obtained by Raman

analysis and the increase of the electrical resistance

presented earlier. Therefore, for the following

experiment, the plasma power was reduced to 100W

and the treatment time was reduced to 10 seconds

only. CNT/PVA pre-pregs were fabricated as

described earlier with a 100-layer sheet sample cut

into two equal halves, one of which was kept

pristine and the other functionalized with plasma.

The results are presented in Figure 12 for the case of

using lower power plasma.

An approximate 117% net increase in

tensile strength is observed for samples treated with

lower plasma power and less exposure time. This

increase in strength could be attributed to two

distinct phenomena working in synergy to improve

the strength. First, a better impregnation of the sheet

with the polymer solution is achieved due to

increased hydrophilicity of the nanotubes. Second,

hydrogen bonding interactions between the –OH

groups of PVA and –COOH and –OH groups

generated on the nanotube surface is created by the

plasma treatment. Table 6 shows the data from the

above described experiment using lower power

plasma.

Figure 12. Stress-strain curves for CNT/PVA pre-

pregs with: (A)-Pristine; (B)-Plasma treated sheets.

Lower power plasma is used here.

Table 6. Mechanical properties of pristine and lower

power plasma functionalized CNT PVA prepregs.

Sample type Mean

Young's

Modulus

(GPa)

Mean

Tensile

Strength

(MPa)

Pristine/Untreated

sheet

23.3 168.8

Plasma Functionalized

(100W10s)

39.4 366.5

Thus, plasma has presented itself as an

attractive tool for functionalization of CNTs and

could be instrumental in the development of strong

composite materials of the future. But, there is

potential to greatly increase the properties of CNT

sheet composites by using several new processing

techniques. First, the CNT used are wavy. The

waviness causes the CNT to be spaced apart which

reduces the Van der Waals forces and does not

allow the CNT to all be loaded at the same time,

thus reducing the strength of the sheet. Also the

CNT have defects which significantly reduces their

strength. Thermally annealing the CNT at high

temperature will make the CNT in the arrays

straighter and stronger. Pre-stretching the sheet

during drawing (as done by other groups) will also

straighten the CNT and make the load transfer more

uniform in the sheet. An aerospace resin to replace


ISBN: 978-1-61804-164-7 333

the PVA may increase the shear strength between

nanotubes and increase the strength of the sheet.

Finally, the use of longer nanotubes (e.g. 5-10 mm

instead of 0.5 mm long) may increase the load

transfer from nanotube to nanotube in the sheet. The

combination of all these changes may greatly

increase the strength of CNT sheet composites.

4. Conclusions and Future work The manufacturing of dry spun sheets of multi-

walled carbon nanotubes has been discussed. A

review of the synthesis, processing,

functionalization and characterization was

presented. The application of atmospheric pressure

plasma as a tool to carry out fast, efficient and clean

functionalization of CNTs was demonstrated.

Plasma functionalized sheets were characterized by

Raman spectroscopy, FTIR spectroscopy, X-ray

Photoelectron Spectroscopy and Contact Angle

measurement to determine the functional groups on

the nanotube surface. CNT sheet has found many

successful applications. Two applications, a light-

weight, effective EMI shielding material and

reinforcement of strong polymer composites were

discussed. Plasma functionalized sheet composites

were shown to perform better than pristine sheet

composites. Thus, plasma has been identified as a

fast, clean and efficient tool to functionalize carbon

nanotubes.

For future work, it is crucial to optimize the

plasma power and treatment to produce the best

results. It will also be beneficial to understand the

mechanism of plasma functionalization of the

nanotubes by studying the active species in the

plasma using Optical Emission Spectroscopy (OES).

The use of other polymer matrix materials such as

epoxy and bismaleimide resin will also be explored.

Quantitative analysis of the functional groups on the

sheet surface with the Temperature Programmed

Desorption (TPD) technique should also help in

optimizing the process. Lastly, consistent production

of spin-capable arrays of carbon nanotubes by CVD

is crucial for the advancement in this field of

research. The latter will allow the manufacture and

implementation of thicker, multilayered CNT sheets

which are expected to be easier to handle and more

useful in manufacturing polymer composites. Such

experiments with CNT sheets consisting of several

thousand layers are in progress at UC and shall be

reported in the future. Several new processing

techniques will be combined and are expected to

greatly increase the strength of CNT sheet

composites.

Acknowledgements We are grateful to the funding agencies: NSF

through grant CMMI-07272500 from NCA&T, a

DURIP-ONR grant, NSF SNM grant 1120382, and

ERC supplemental STTR funded by NSF (2010-

2012) “Translational Research to Commercialize

CNT and Mg based Materials for Biomedical and

Industrial Nanotechnology Applications”. We would

also like to acknowledge Feng Wang, Christopher

Katuscak and Sandip Argekar for their assistance in

the lab, Doug Hurd for his assistance in the machine

shop, and General Nano LLC for granting access to

their e-Beam evaporator. Research to investigate use

of the sheet materials for firefighter personal

protective garments is sponsored by the Univ. of

Cincinnati Education and Research Center Targeted

Research Training program (UC ERC-TRT

Program).

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ISBN: 978-1-61804-164-7 335

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