Functionalization effects on the electrical properties of multi-walled carbon nanotube-polyacrylamide composites

Multi-walled carbon nanotubes (MWNTs)-polyacrylamide (PAM) composites have been prepared using as purified, with ball milling and functionalized MWNTs by solution cast technique and characterized through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A comparative study has been made on the electrical property of these MWNTs-PAM composites with different MWNTs loadings. It has been shown that the ball milling and functionalization of MWNTs improves the dispersion of MWNTs into the polymer matrix. As the MWNTs loading increases from 0 to 40 wt% electrical conductivity of composite film increases by approximately 7 orders of magnitude whereas the electrical conductivity of functionalized composite film increases only approximately 4 orders of magnitude with respect to the pure PAM film. A model based on power law percolation for the electronic behavior of above composite has been developed and shows good agreement with the experimental data.