METASTABLE REACTION MIXTURES FOR THE IN SITU POLYMERIZATION OF CONDUCTING POLYMERS

摘要

Conducting polythiophene films are produced by the oxidation of bithiophene or terthiophene monomers using phosphomolybdic acid, wherein the reagents are first combined to form a metastable solution, the solution is then cast as a film, and polymerisation ultimately initiated by evaporation of the solvent The equivalent formation of polypyrrole via the oxidation of pyrrole using phosphomolybdic acid has been previously demonstrated, but this approach cannot be applied directly to thiophene, which has too high an oxidation potential Bithiophene and terthiophene have lower oxidation potentials, close to that of pyrrole This work suggests the previously demonstrated method is suitable for general application, requiring only the proper matching of monomer and oxidant redox potentials, and the selection of a suitable solvent and starting concentration Smooth, spin-coated polythiophene films having thicknesses of 100 to 200 run and conductivities in the range 0.2 to 0.3 S-cm^-1 have been prepared.