Electrical and optical properties of conducting polymer in liquids

Electrical properties such as electrical conductivity and dielectric property; optical properties such as photoconductivity and photoluminescence and mechanical properties such as viscosity of conducting polymers including polythiophene, poly(p-phenylenevinylene) and polyacetylene derivatives in liquids, that is, in solution and fused liquid state have been studied as functions of the molecular structure and temperature. These properties in these substituted derivatives, were strongly dependent on the substituent, and changed drastically at the melting point, which has been discussed by taking the conformation of the substituents and inter polymer main chain interactions into consideration. Electrorheological effects in conducting polymer solutions has also been studied and was found to be dependent on both molecular structures and temperature, which can be also interpreted in terms of molecular reorientation and changes of molecular conformation and interchain interaction.