Electrical properties of polyaniline suspensions

The ordering of electrically conducting polyaniline particles dispersed in a non-conducting Liquid, 1,2,4-trichlorobenzene, in a weak electric field (of the order V mm(-1)) has been studied. The time needed for the formation of conducting chains, depending on the applied voltage, the polyaniline concentration and the viscosity of the suspension medium, was used to calculate the effective relative electric permittivity for polyaniline, epsilon(p)=4.8, responsible for the dipole-dipole interaction leading to the structure formation. Nonlinear limit current-voltage characteristics typical of electrorheological suspensions were observed. The formation of the conducting chains could be followed in an optical microscope. (C) 1998 Elsevier Science S.A. All rights reserved.