Frequency-dependent conductivity and dielectric permittivity of polyaniline/TiO2 composites

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 10(2)-10(6) 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 10(2)-10(6) 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 3 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.