Effect of loading titanium dioxide on structural, electrical and mechanical properties of polyaniline nanocomposites

•Template free in situ chemical polymerization.•XRD reveals, 10% critical concentration of the dopant.•Nano size crystal structure by Transmission Electron Microscopy (TEM).•3D variable range hopping.•Enhancement in mechanical properties.

Nanocomposites based on Polyaniline Titanium dioxide (PANI-TiO2) were prepared by in situ chemical polymerization. The structure was confirmed by X-rays diffraction studies. The interesting behavior of the XRD pattern around 10% TiO2 content was marked as critical concentration of the dopant. The crystallite size was found to increase for PANI-TiO2 nanocomposites. Charge transport mechanism was investigated by temperature dependent dc electrical conductivity measurements in the temperature range of 293 K–353 K. An increase in dc conductivity was found on addition of TiO2 at all temperatures and three dimensional variable range hopping (3D VRH) model was the most probable model of charge transport. Activation energy, density of states and hopping length were calculated and found to be influenced by TiO2 incorporation. Structural morphology was studied by scanning electron microscopy (SEM). The granular structure and grain size increased and was confirmed by Transmission Electron Micrographs. The tensile modulus as a function of TiO2 loading in PANI showed enhancement in mechanical properties.