DC electrical conductivity retention and electrical compensation of polyaniline by TiO₂ at higher loading percentages in polyaniline@TiO₂ nanocomposites

Abstract

Electrically conductive HCl-doped polyaniline (Pani)@titanium dioxide (TiO₂) nanocomposites were prepared by the in-situ oxidative polymerization of aniline in the presence of different amounts of TiO₂ nanoparticles. The synthesized Pani@TiO₂ nanocomposites were characterized by transmission electron microscopy, X-ray diffraction, UV-visible spectroscopy, and thermogravimetric analysis. The stability of the Pani@TiO₂ nanocomposites in terms of their electrical conductivity retention was examined under isothermal and cyclic aging conditions, and compared with that of pure Pani. The Pani@TiO₂ nanocomposites showed higher thermal stability than pure Pani. The effect of competitive doping/de-doping by TiO₂ was examined at different Pani to TiO₂ weight ratios. TiO₂ at a higher weight percentage was found to be involved in the de-doping type of interaction with Pani, leading to its neutralization, which was found to be similar to the dedoping phenomenon, as in the case of neutralization in basic media. The novel mechanism for this de-doping type of interaction of TiO₂ with Pani has also been proposed.