Dielectric and conductivity studies of in-situ oxidative polymerized PANI@TiO2 nanocomposite

Abstract

This paper reports the synthesis of polymer matrix PANI and PANI/TiO2 nanocomposite under ice-cold conditions using in-situ oxidative polymerization process. The dielectric and dc conductivity measurements of both the samples are studied under vacuum at room temperature conditions using two probe method. The real (ε′) and imaginary (ε′′) parts of dielectric constant are studied as a function of frequency ranging from 50 Hz to 1 MHz. The dielectric studies show that nanoparticles strongly affect the properties of PANI/TiO2 nanocomposite. Addition of TiO2 may have resulted in the development of more proficient network for charge transport in PANI matrix which results in enhancement of dielectric properties. The dc conductivity measurements are performed by taking variation of current with temperature at three different voltages. The dc conductivity values increases with increasing temperature. Also the activation energies exhibit a decreasing trend with increase in applied voltage. This enhanced dc conductivity values can be accredited to better porosity of nanocomposite film which further results in increase of charge transport occurring due to effective interaction between metal oxide (TiO2) nanoparticles and polymer matrix (PANI).