OPTICAL AND RHEOLOGICAL PROPERTIES OF POLY(3-ALKYLTHIOPHENE) SOLUTION

Contrary to the case of the solution of poly(3-alkylthiophene) in chloroform, the solution of poly(3-alkylthiophene) in anisole exhibits anomalous voltage-dependent viscosity. That is, in the temperature range of 10-40-degrees-C, the viscosity increases with increasing applied voltage but that at temperature as high as about 60-degrees-C decreases with increasing applied voltage, with a tendency to saturation. The absorption spectrum of poly(3-alkylthiophene) in anisole also exhibits a redshift of about 70 nm above the critical temperature. These anomalies are discussed in terms of the change in conformation of poly(3-alkylthiophene) in solvents.