Dielectric Properties of PAni/ZnO Composite

Abstract

Samples of polyaniline and its composite with ZnO were prepared by electrochemical polymerization (ECP) method. ECP occurred in one-compartment by three-electrode cell processes in which platinum mesh is used as a counter electrode (cathode) and ITO as a working electrode (anode), and Ag/AgCl as reference electrode at 1 V, 1 mA and 0.2 scan rate. Variation in dielectric constants and AC conductivity was monitored with relative humidity (% RH) ranges between 10 and 90% RH and frequency ranges between 20 Hz and 5 MHz. Presence of ZnO particles results in enhanced dielectric properties and an increase in conductivity. It was observed that the dielectric constant of ZnO-doped PAni composites has lower value compared to the PAni and shows decreasing behavior with frequency and %RH. This decreasing behavior of tan δ and ε′ may be explained in terms of formation of interface between particles of ZnO and molecular assembly of PAni.