Temperature and Composition Dependent Variation of Resistivity of PANI/TiO2 Nanocomposites

Abstract

The titanium oxide (TiO2) has been prepared by peptization method and Polyaniline/Tin oxide (PANI/TiO2) nanocomposites have been successfully synthesized by in-situ polymerization method. The PANI/TiO2 nanocomposites were prepared by varying the weight percentage of TiO2 nanoparticles such as 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% into the fixed amount of aniline monomer. The prepared samples were characterized by XRD, SEM and TGA. The diffraction patterns of the nanocomposites approaches towards crystanallity with increasing wt% of TiO2 nanoparticles in the PANI/TiO2 nanocomposites. SEM shows nanoparticles were uniformly dispersed and one can find that inorganic nanoparticles. The DC conductivity was carried out by Van der Pauw method in the temperature range 80–300 K. The conductivity of the pure PANI was found to be 4.46 S/cm at room temperature. The increase of wt% of TiO2 nanoparticles in PANI matrix from 0 to 50 wt% subsequently decreases the room temperature conductivity (σ RT) from 4.46 to 0.86 S/cm. The temperature dependent DC electrical conductivity of all the samples increases with increasing temperature exhibiting semiconducting behaviour following Mott's 3D variable range hopping (VRH) model. The PANI/TiO2 nanocomposites could be used for gas sensing application as SEM images reveal the presence of high porosity.