Synthesis and characterization of a soluble and transparent conducting polymer, poly(3,4-ethylenedioxythiophene)

A soluble conducting polymer, poly(3,4-ethylenedioxythiophene), has been prepared by various synthetic conditions. The physical properties of a resulting polymer. such as solubility. optical property, and electrical property, were monitored as a function of the concentration of an oxidant and a dopant, as well as reaction time. An increase in the molecular weight with reaction time was clearly observed by GPC and the best results in the solubility and conductivity was obtained using methanol and ferric toluenesulfonate as a solvent and an oxidant, respectively. In chloroform solvent, the solubility reached up to > 90 % and the conductivity of the cast film reached 1.85 S/cm.