Frequency-Dependent Conductivity and Dielectric Permittivity of Polyaniline/TiO₂ Composites

Abstract

Conducting polyaniline/Titanium di-oxide (PANI/TiO2) composites have been synthesized by insitu deposition technique by placing fine graded TiO2 in polymerization mixture of aniline. The PANI/TiO2 composites have been synthesized with various compositions viz., 10,20,30,40 and 50 wt % of TiO2 in PANI. The ac conductivity was studied in the frequency range 102–106 Hz. It is observed from the ac conductivity studies that the ac conductivity is found to be constant up to 105 Hz and there after it increases steeply which is a characteristic feature of disordered materials. The dielectric behaviour was also investigated in the frequency range 102–106 Hz. It is observed from the dielectric studies that the value of dielectric constant decreases up to 20 wt % and later it increases rapidly up to 50 wt %. Similarly it is also seen that the tan δ values decreases rapidly up to 20 wt % and then increases up to 40 wt %, thereafter slowly increases up to 50 wt %. At higher frequencies these composites exhibit almost zero dielectric loss. The dimensions of TiO2 particles in the matrix have a greater influence on the conductivity values and the observed dielectric values.