Transport Properties of Conductive Polyaniline Nanocomposites Based on Carbon Nanotubes

Abstract

Intrinsically conducting polymers have been studied extensively due to their intriguing electronic and redox properties and numerous potential applications. To improve and extend their functions, the fabrication of multifunctional conducting polymer nanocomposites has attracted a great deal of attention with the advent of nanoscale dimension. In this paper we report the comparative study of nanocomposite synthesized by an in-situ oxidative polymerization of aniline monomer in the presence of functionalized multiwall carbon nanotubes (MWCNT) with that of pure polyaniline (PANI). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and x-ray diffraction (XRD) are employed to characterize the pure PANI and the PANI-CNT nanocomposite. XRD and SEM reveal the homogeneous coating of PANI onto the CNT indicating that carbon nanotubes were well dispersed in polymer matrix. The interaction between the quinoid ring of PANI and the MWCNT causes PANI chains to be adsorbed at the surface of MWCNT, thus forming a tubular core surrounding the MWCNT was confirmed from FTIR. Nanocomposite shows high electrical conductivity compared to pure PANI. The enhancement in conductivity of the nanocomposite is due to the charge transfer effect from the quinoid rings of the PANI to the MWCNT. The effect of MWCNT on the transport properties of PANI in the form of the transport parameters such as charge localization length, most probable hopping distance and charge hopping energy in the temperature range 300-430 K was also studied.