Insulator-Metal transition in Polyaniline induced by plasticizers

Abstract

We show for the first time that the addition of classical plasticizers. such as triphenyl or tritolyl phosphate, to solution processed polyaniline (PANI) films leads to dramatic changes in their transport properties, despite the fact that both admixtures are incapable to interact with PANI via any type of doping. In particular, a veritable plasticizer induced Insulator-Metal transition takes place, as revealed by the change of the sign of the temperature coefficicnt of the reduced activation energy W. Since X-Ray diffraction studies indicate that the plasticizers do not enter into the crystalline parts of the polymer, hut only modify its amorphous halo. the obtained results are consistent with the inhomogeneous disorder model.