ELECTROCHEMICAL POLYMERIZATION OF THIOPHENE UNDER ULTRASONIC-FIELD

Films of polythiophene were prepared by electrochemical oxidation under ultrasonic field. The ultrasonic irradiation had an influence on the conditions and the properties of the as-polymerized films. In the absence of ultrasonic irradiation, the as-polymerized films became brittle gradually when the electrolytic current density exceeded the value of 5 mA/cm**2. Flexible and tough films with the tensile modulus of 3. 2 GPa and strength of 90 MPa were obtained even at a high current density of 10 mA/cm**2 with ultrasonic irradiation. The doping level increased with increasing electrolytic current density at a given current density, the levels for the irradiated series were highrthan those for unirradiated series, which led to a high electrical conductivity (130-150 S/cm) for the irradiated series. Cyclic voltammetry indicated a higher diffusion rate for the films prepared under ultrasonic field compared with those prepared without irradiation.