Integration of conducting polymer network in non-conductive polymer substrates

Abstract

A new method for integration of conjugated, inherently conducting polymers into non-conductive polymer substrates has been developed. A layer of the conducting polymer is polymerised by chemical oxidation, e.g. using Fe(III) p-toluene sulfonate (ferri tosylate) followed by washing with a solvent which simultaneously removes residual and spent oxidant and at the same time dissolves the top layer of the polymer substrate. This results in an integration of the conducting polymer into the surface layers of the polymer substrate. Several combinations of conducting polymers and substrates have been tested, with particular focus on poly(3,4-ethylenedioxythiophene) (PEDOT) on PMMA substrates. The structural, electrical and mechanical properties of this system has been characterised by atomic force microscopy, conductance measurements, and tribological tests. Furthermore, measurement of conductivity and optical absorption during sequential reactive ion etching has allowed for analysis of the PEDOT distribution within the surface layer of the PMMA substrate. The surface resistance of the conducting polymer layer remains low while the surface layer at the same time adapts some of the mechanical properties of the substrate, resulting in a highly conducting surface with very good wear resistance.