Piezoresistivity of conducting polyaniline/BaTiO₃ composites

Abstract

Conducting polyaniline/barium titanate (PANI/BaTiO₃) composites exhibiting piezoresistivity properties have been synthesized by the in situ deposition technique by placing a fine grade powder of BaTiO₃ in the polymerization reaction mixture. The polyaniline was formed preferentially on the ceramic particles giving a much higher yield for PANI than in absence of the BaTiO₃ These composites exhibited piezoresistivity with the piezosensitivity being maximum at a certain composition. The current-voltage characteristics clearly revealed a nonlinear space charge controlled charge transport process. A large hysteresis in these characteristics was also observed which was dependent on the BaTiO₃ content in a composite. The various results have been explained on the basis of the charge transport mechanism in the heterogeneous conducting material having insulating domains dispersed in it.