Effect of Templating Graphitization on Electrical Conductivity of Electrospun Carbon nanofiber Conference Paper uri icon

abstract

  • © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. To study the graphitic templating effect of carbon nanotubes (CNTs) in carbon nanofibers (CNFs) on electrical conductivity of CNFs, electrospun CNF/CNTs hybrid nanofibers with various CNT contents (0.1wt.%-0.5 wt.%) were fabricated via electrospinning and carbonizatgion at 1100 °C. Hot-drawing was applied to as-spun polyacrylonitrile (PAN)/CNTs precursor nanofibers prior to carbonization to further modify their microstructure. The evolution of microstructure of precursor hybrid nanofibers was examined by different characterization methods, such as polarized FT-IR, polarized Raman and X-Ray diffraction azimuthal, which shows an evident alignment increase of PAN chains and CNTs within PAN/CNTs nanofibers caused by hot-drawing. Effective reinforcement modulus of CNTs in 0.1 wt.% PAN/CNTs hybrid nanofibers was measured to be as high as ~2.1 TPa (nearly twice the modulus of individual CNTs), due to the formation of highly order polymer interphase with higher mechanical properties compared to bulk PAN around CNTs. Moreover, the alignment of the graphitic domains within CNFs due to hot-drawing of precursor effectively improved the electrical conductivity of CNF from 145 S/cm to 241 S/cm. On the other hand, electrical conductivity of as fabricated CNF/CNTs was lower than pure CNF due to the decreased molecular alignment of PAN in as electrospun PAN/CNT composite fibers which lowered the graphitic alignment in CNF/CNTs. However, this loss in conductivity was partially compensated for by the templating effect of CNTs. This study sets a good starting point for fabricating low cost highly conductivity CNF through exploiting the templating graphitization of CNTs.

author list (cited authors)

  • Cai, J., & Naraghi, M.

citation count

  • 7

publication date

  • January 2017