The structural and electrical properties of polyaniline carbon nanotubes (PANI-CNTs) composite

Abstract

Carbon nanotubes (CNTs) doped polyaniline (PANI) nanocomposite was synthesized by chemical polymerization method in the presence of HCl medium. The structure of the PANI/CNTs composite was confirmed by X-ray diffraction (XRD) technique. The SEM results showed granular and tube like shape for PANI and CNTs respectively. The SEM characterization of PANI-CNTs composite revealed a uniform wrapping of CNTs by PANI forming a core-shell nanostructure. The temperature dependent dielectric measurements were performed in the frequency range of 0.1 kHz-1 MHz. Dielectric measurements revealed the strong interactions between PANI and CNT nanoparticles causing a beneficial effect on stability of the composites. The dielectric constant followed the Maxwell-Wagner interfacial polarization. The frequency dependent conductivity obeyed a power law of frequency. Temperature has an effect on dielectric constant values of composite sample. Heat treatment affected the dipole polarization by reducing the relaxation time and hence contributed to the enhancement of dielectric parameters. Dielectric properties of composites were found to be improved due to addition of carbon nanotubes, which can improve the formation of a more efficient network for charge transport mechanism in the base polyaniline matrix. The border between polyaniline and CNTs can play an important role in yielding a large dielectric constant in the nanocomposites.