Tailored alignment of functionalized multiwall carbon nanotubes in epoxy

Ambuj Sharma, Charles E. Bakis, Kon Well Wang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

The objective of this paper is to investigate the effect of frequency and strength of electric fields applied during processing on the alignment of functionalized multiwall carbon nanotubes (MWCNTs) in epoxy. The degree of alignment is assessed based on the electrical resistance parallel and transverse to the direction of field. The strengths of electric fields used for alignment were 100 and 300 V/cm and the frequencies at which these electric fields were applied ranged from 100-100k Hz. The MWCNTs had either covalent (amine) or non-covalent functionalization and were added to the epoxy at 0.5 wt% concentration. For noncovalently functionalized MWCNTs, the DC electrical resistivity was found to be sensitive to the nature of the field applied during processing. In comparison to no applied field, the parallel DC resistivity decreased and the transverse DC resistivity varied versus frequency, with a peak in electrical anisotropy observed at a 100 Hz alignment frequency. The main source of the variation of anisotropy was the decreasing transverse resistivity with increased frequency, whereas the parallel resistivity was nearly constant for each frequency. The parallel specific AC impedance of these specimens decreased with increasing measurement frequency, regardless of alignment frequency, indicating dielectric behavior. For amine functionalized MWCNTs, the DC resistivity did not change appreciably among the specimens prepared with or without electrical field. Although the DC resistivity had essentially no anisotropy in these cases, it was 5-8 orders of magnitude less than DC resistivities obtained with the non-covalently functionalized MWCNTs. The parallel AC impedance of these specimens was constant up to a frequency of 100k Hz, indicating ohmic behavior.

Original languageEnglish (US)
Title of host publicationSAMPE Fall Technical Conference and Exhibition - Multifunctional Materials
Subtitle of host publicationWorking Smarter Together, SAMPE '08
StatePublished - Dec 1 2008
Event2008 SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08 - Memphis, TN, United States
Duration: Sep 8 2008Sep 11 2008

Publication series

NameInternational SAMPE Technical Conference

Other

Other2008 SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08
CountryUnited States
CityMemphis, TN
Period9/8/089/11/08

Fingerprint

Carbon Nanotubes
Carbon nanotubes
Anisotropy
Electric fields
Amines
Acoustic impedance
Processing

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Sharma, A., Bakis, C. E., & Wang, K. W. (2008). Tailored alignment of functionalized multiwall carbon nanotubes in epoxy. In SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08 (International SAMPE Technical Conference).
Sharma, Ambuj ; Bakis, Charles E. ; Wang, Kon Well. / Tailored alignment of functionalized multiwall carbon nanotubes in epoxy. SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08. 2008. (International SAMPE Technical Conference).
@inproceedings{b5b6f63e2f314d799ecfbf9ca1c415af,
title = "Tailored alignment of functionalized multiwall carbon nanotubes in epoxy",
abstract = "The objective of this paper is to investigate the effect of frequency and strength of electric fields applied during processing on the alignment of functionalized multiwall carbon nanotubes (MWCNTs) in epoxy. The degree of alignment is assessed based on the electrical resistance parallel and transverse to the direction of field. The strengths of electric fields used for alignment were 100 and 300 V/cm and the frequencies at which these electric fields were applied ranged from 100-100k Hz. The MWCNTs had either covalent (amine) or non-covalent functionalization and were added to the epoxy at 0.5 wt{\%} concentration. For noncovalently functionalized MWCNTs, the DC electrical resistivity was found to be sensitive to the nature of the field applied during processing. In comparison to no applied field, the parallel DC resistivity decreased and the transverse DC resistivity varied versus frequency, with a peak in electrical anisotropy observed at a 100 Hz alignment frequency. The main source of the variation of anisotropy was the decreasing transverse resistivity with increased frequency, whereas the parallel resistivity was nearly constant for each frequency. The parallel specific AC impedance of these specimens decreased with increasing measurement frequency, regardless of alignment frequency, indicating dielectric behavior. For amine functionalized MWCNTs, the DC resistivity did not change appreciably among the specimens prepared with or without electrical field. Although the DC resistivity had essentially no anisotropy in these cases, it was 5-8 orders of magnitude less than DC resistivities obtained with the non-covalently functionalized MWCNTs. The parallel AC impedance of these specimens was constant up to a frequency of 100k Hz, indicating ohmic behavior.",
author = "Ambuj Sharma and Bakis, {Charles E.} and Wang, {Kon Well}",
year = "2008",
month = "12",
day = "1",
language = "English (US)",
isbn = "9781934551042",
series = "International SAMPE Technical Conference",
booktitle = "SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials",

}

Sharma, A, Bakis, CE & Wang, KW 2008, Tailored alignment of functionalized multiwall carbon nanotubes in epoxy. in SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08. International SAMPE Technical Conference, 2008 SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08, Memphis, TN, United States, 9/8/08.

Tailored alignment of functionalized multiwall carbon nanotubes in epoxy. / Sharma, Ambuj; Bakis, Charles E.; Wang, Kon Well.

SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08. 2008. (International SAMPE Technical Conference).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Tailored alignment of functionalized multiwall carbon nanotubes in epoxy

AU - Sharma, Ambuj

AU - Bakis, Charles E.

AU - Wang, Kon Well

PY - 2008/12/1

Y1 - 2008/12/1

N2 - The objective of this paper is to investigate the effect of frequency and strength of electric fields applied during processing on the alignment of functionalized multiwall carbon nanotubes (MWCNTs) in epoxy. The degree of alignment is assessed based on the electrical resistance parallel and transverse to the direction of field. The strengths of electric fields used for alignment were 100 and 300 V/cm and the frequencies at which these electric fields were applied ranged from 100-100k Hz. The MWCNTs had either covalent (amine) or non-covalent functionalization and were added to the epoxy at 0.5 wt% concentration. For noncovalently functionalized MWCNTs, the DC electrical resistivity was found to be sensitive to the nature of the field applied during processing. In comparison to no applied field, the parallel DC resistivity decreased and the transverse DC resistivity varied versus frequency, with a peak in electrical anisotropy observed at a 100 Hz alignment frequency. The main source of the variation of anisotropy was the decreasing transverse resistivity with increased frequency, whereas the parallel resistivity was nearly constant for each frequency. The parallel specific AC impedance of these specimens decreased with increasing measurement frequency, regardless of alignment frequency, indicating dielectric behavior. For amine functionalized MWCNTs, the DC resistivity did not change appreciably among the specimens prepared with or without electrical field. Although the DC resistivity had essentially no anisotropy in these cases, it was 5-8 orders of magnitude less than DC resistivities obtained with the non-covalently functionalized MWCNTs. The parallel AC impedance of these specimens was constant up to a frequency of 100k Hz, indicating ohmic behavior.

AB - The objective of this paper is to investigate the effect of frequency and strength of electric fields applied during processing on the alignment of functionalized multiwall carbon nanotubes (MWCNTs) in epoxy. The degree of alignment is assessed based on the electrical resistance parallel and transverse to the direction of field. The strengths of electric fields used for alignment were 100 and 300 V/cm and the frequencies at which these electric fields were applied ranged from 100-100k Hz. The MWCNTs had either covalent (amine) or non-covalent functionalization and were added to the epoxy at 0.5 wt% concentration. For noncovalently functionalized MWCNTs, the DC electrical resistivity was found to be sensitive to the nature of the field applied during processing. In comparison to no applied field, the parallel DC resistivity decreased and the transverse DC resistivity varied versus frequency, with a peak in electrical anisotropy observed at a 100 Hz alignment frequency. The main source of the variation of anisotropy was the decreasing transverse resistivity with increased frequency, whereas the parallel resistivity was nearly constant for each frequency. The parallel specific AC impedance of these specimens decreased with increasing measurement frequency, regardless of alignment frequency, indicating dielectric behavior. For amine functionalized MWCNTs, the DC resistivity did not change appreciably among the specimens prepared with or without electrical field. Although the DC resistivity had essentially no anisotropy in these cases, it was 5-8 orders of magnitude less than DC resistivities obtained with the non-covalently functionalized MWCNTs. The parallel AC impedance of these specimens was constant up to a frequency of 100k Hz, indicating ohmic behavior.

UR - http://www.scopus.com/inward/record.url?scp=78249250886&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78249250886&partnerID=8YFLogxK

M3 - Conference contribution

SN - 9781934551042

T3 - International SAMPE Technical Conference

BT - SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials

ER -

Sharma A, Bakis CE, Wang KW. Tailored alignment of functionalized multiwall carbon nanotubes in epoxy. In SAMPE Fall Technical Conference and Exhibition - Multifunctional Materials: Working Smarter Together, SAMPE '08. 2008. (International SAMPE Technical Conference).