Metastable reaction mixtures for the in situ polymerization of conducting polymers

The widespread use of conducting polymers in technological applications has been hindered by poor processability; strong intermolecular interactions prohibit thermal processing and reduce solubility in conventional solvents. To date, there has been a focus on the disruption of these interactions through the functionalization of the polymer backbone or the stabilization of colloidal polymer. In this work, we present a generalized approach to the synthesis of conducting polymers that uses an easily processable mixture of monomer and oxidant that is metastable in solution, yet rapidly polymerizes upon solvent evaporation. This procedure was originally used for the polymerization of pyrrole and is now demonstrated as a general approach by extending the method to the polymerization of thiophene. The method allows the casting and spin-coating of films with similar conductivities and redox properties to those of electrochemically generated thin films, without the need for a conducting substrate. Films produced via spin-coating are smooth with a thickness of 100-200 nm and show conductivities in the range 0.2-0.3 S cm(-1). Microscopic and spectroscopic characterizations are also presented.