Structures and electric properties of PANI/polymorphic-ZrO₂ composites

A polyaniline/zirconia (PANI/ZrO₂) composite has been successfully synthesized using an in situ method with HCl used as a doping agent, SDBS as a surfactant and APS as an oxidant. The filler variations were comprised of various phases, which are amorphous, tetragonal, monoclinic and a mixture of tetragonal-monoclinic and varied volumes of 0, 2.5, 5.0, 7.5 and 10%. Amorphous, tetragonal and a mixture of tetragonal-monoclinic ZrO₂ were obtained from purifying natural zircon sand (ZrSiO₄), while monoclinic ZrO₂ was obtained from commercial materials. The structure characterisation was performed using X-ray diffraction and Fourier Transform Infrared (FTIR). The morphology was observed using a Scanning Electron Microscope (SEM). The electrical properties of impedance, dielectric constant and dielectric losses, and electrical conductivity were characterised using Electrochemical Impedance Spectroscopy (EIS). The research results showed that the filler phase had an effect towards the electrical properties of PANI/ZrO₂. The impedance of PANI as well as PANI/ZrO₂ showed a constant phase element (CPE) behaviour with impedance values of 9.87, 9.16, 13.31, and 79.59 kΩ for the composites with amorphous filler, monoclinic filler, tetragonal filler, and tetragonal-monoclinic filler, respectively. The dielectric constant and dielectric losses decreased with the increasing amount of ZrO₂ filler. The AC conductivity of PANI/ZrO₂ was found to be lower when compared to PANI for all of the filler phases and volume fractions.