Electrorheological effect in suspensions of conductive polymers

Electrorheological (ER) effect relies on increase of viscosity of a fluid under electric field. In the present study electrorheological fluids (ERFs) were prepared out of FeCl3 doped poly(p-phenylene) and silicone oil. Rheological properties of the ERFs were measured under electric field up to 2.2 kV/mm. Influence of electric field and composition of the fluids on magnitude of the ER effect were studied. It was found that the ER effect is observed in ERFs containing amorphous polymer and not a semi-crystalline one. This has been attributed to ionic contribution of conductivity in the amorphous polymer which is not present in the crystalline material.