Dielectric constant and ac conductivity in polyaniline derivatives

We report our results on ac conductivity and dielectric constant measurements at 10 kHz on polyaniline and derivatives of polyaniline having alkyl ring-substituents. A comparison with de conductivity is made to gain further insight into the conduction mechanism. The room temperature de and ac conductivities are similar; however, deviations at lower temperatures characteristic of conduction mechanisms typical of variable range hopping are observed. This deviation is larger for samples having greater disorder. Disorder also suppresses the temperature dependence of the dielectric constant.