Conductivity of polyaniline/1,2,4-trichlorobenzene composites during freezing and melting transitions

Polyaniline suspensions in 1,2,4-trichlorobenzene produced solid composites after freezing. Changes in electric conductivity after the solidification and during the melting transition have been investigated in dependence on conducting polymer concentration. Below the percolation threshold, the conductivity of frozen composites was lower than that of original suspensions. If conducting particle concentration was above this critical value, then the conductivity increased after the suspension froze. Conductivity both in the liquid and in the solid state was higher when polyaniline particles in the suspensions were polarized in electric field. In this case, conductive pathways connecting the electrodes were produced by organized particle chains.