Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-24T15:33:43.695Z Has data issue: false hasContentIssue false

Gelation, Electrical Conductivity and Elasticity of PAM- MWNT

Published online by Cambridge University Press:  28 January 2011

Gulsen A. Evingur
Affiliation:
İstanbul Technical University, 34469, Maslak, İstanbul, TURKEY
Önder Pekcan
Affiliation:
Kadir Has University, 34320, Cibali, İstanbul, TURKEY
Get access

Abstract

Polyacrylamide- Multiwalled carbonnanotube (PAM- MWNT) composites were prepared via free radical crosslinking copolymerization with different amounts of MWNT varying in the range between 0.1 and 15 wt. %. PAM- MWNT composite gels were characterized by fluorescence, dielectric spectroscopy and the tensile testing technique. A small content of doped nanotubes dramatically changed gelation time, conductivity and young modulus, respectively. The gel fraction exponent, β of PAM- MWNT composite gels were measured for various monomer and MWNT concentrations and observed that the gel fraction exponent β agrees best with the percolation theory for various amounts of PAM- MWNT. These polymer systems which are initially of an isolator character are doped with carbon nanotubes of nano dimensions and when the amount of this addition exceeds a critical value (0.3 wt. % MWNT) known as the percolation threshold, then composite gel systems with carbon nanotubes become electrically conducting structures with a critical exponent around r=2 which is close to the theoretical prediction of this value in 3D percolated system as known random resistor network. The observed elasticities are decreased above 3 wt. %MWNT with critical exponent around y=0.72 which is indicative of a transition from liquid-like to solid-like viscoelastic behavior.

Type
Research Article
Copyright
Copyright © Materials Research Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Ajayan, P. M., Stephan, O., Colliex, C., Trauth, D., Science, 265, 1212, (1994).Google Scholar
2. Satarkar, N. S., Johnson, D., Marrs, B., Andrews, R., Poh, C., Gharaibeh, B., Saito, K., Anderson, K. W., Hilt, J. Z., J. App. Poly. Sci., 117, 1813, (2010).Google Scholar
3. Stauffer, D., Coniglio, A., Adam, M., Adv. Poly. Sci.., 44, 103, (1982).Google Scholar
4. Stauffer, D., Aharony, A., Introduction to Percolation Theory. (Taylor and Francis, 1994).Google Scholar
5. de Gennes, P. G., Scaling Concepts in Polymer Physics.(Cornell University Press., 1979).Google Scholar
6. Bergman, D. J., Imry, Y., Phys. Rev. Lett., 39, 1222, (1977).Google Scholar
7. Sahimi, M., Application of Percolation Theory. (Taylor and Francis.1994).Google Scholar
8. Anseth, K. S., Bowman, C. N., Peppas, L. B., Biomaterials, 17, 1647, (1996).Google Scholar