Measuring of electrical properties of MWNT-reinforced PAN nanocomposites

Abstract

Nano-web sheets of polyacrylonitrile (PAN) reinforced by carbon nanotubes (CNT) were prepared by electrospinning process. Multi wall nanotubes (MWNT) were dispersed mechanically by high shear mixing using a homogenizer device. It has been found that the spinning solution presented an electrical percolation threshold less than 0.5wt.% of MWNT. Electrical volume and surface conductivity of the obtained nano-webs was studied by measuring the electrical volume resistance and surface resistance thanks to home-made plate electrodes. Scanning electron microscope (SEM) has been used to characterize the nano-web sheets produced. The average filament diameters range from 320 to 750nm depending on the concentration of CNT and of PAN. From an electrical point of view, it has been observed that the electrical volume conductivity increases by about six orders of magnitude from 2 × 10 -12S/m for pristine PAN to 4×10 -6S/m for PAN charged by MWNT. Increasing the pressure on the specimen induces an exponential decrease of the volume resistivity while surface resistivity shows no significant changes, neither between pristine PAN and reinforced nano-webs, nor among reinforced nano-web in relation to MWNT concentration (in the limit of the study). This observed behavior is very interesting in the context of sensor developments. Copyright © 2012 Sliman Almuhamed et al.