Chemical polymerization of 3,4-ethylenedioxythiophene using an aqueous medium containing an anionic surfactant

We found that a good yield of poly(3,4-ethylenedioxythiophene) (PEDOT) was obtained by emulsion polymerization in which an anionic surfactant and Fe-2 (SO4)(3) were used as an emulsifier and an oxidant, respectively. The major feature of this polymerization is that highly conductive PEDOT is formed i n an aqueous medium containing such a low concentration of 3,4-ethylenediox ythiophene (EDOT) and Fe-2(SO4)(3) as 0.05 M. This is most likely due to th e polymerization progressing in the innumerable micelles where hydrophobic EDOT is concentrated. The thermal stability of PEDOT obtained here is super ior to that of polypyrrole prepared in a similar manner, although its moist ure stability is inferior. (C) 1998 Elsevier Science S.A. All rights reserv ed.