Anodic polymerization of thiophene microemulsions and liquid derivatives from crystals

Intrinsically conducting polymers (ICPs) of substituted thiophenes were obt ained by anodic polymerization from microemulsions of the heterocyclic arom atic oils 3,4-ethylenedioxythiophene (EDOT) and 3-methoxythiophene (MOT) wi th high oil and nonionic surfactant content. A liquid crystal was polymeriz ed for the first time allowing the formation of a free membrane in a platin um loop. Polymerization takes place under all conditions, but current trans ients and cyclovoltammograms yield a clear dependence of ICP properties on the composition of the microemulsion. Optimum conditions obtained for the p olymerization current do not coincide with optimum redox properties. To und erstand these results, the multicomponent systems were characterized by pha se behavior, conductivity, viscosity and dynamic light scattering. For micr oemulsions of EDOT, 0.5 M aqueous LiClO4 solution and a commercial alkyl po lyethoxylate, a transition from the oil-in-water to the bicontinuous microe mulsion was found at an oil content of about 45%. Continuous water domains exist up to a very high monomer content of more than 60% by weight. (C) 200 1 Elsevier Science Ltd. All rights reserved.