The determination of the surface energy of conducting polymers by inverse gas chromatography at infinite dilution

Abstract

Inverse gas chromatography (IGC) has been used at infinite dilution to determine the dispersive and acid–base contributions to the surface energy of inherently conducting polymer (ICP) powders and nanocomposites, with an emphasis on polypyrrole bulk powder. New and previously published results are discussed and show that polypyrrole and polyaniline are high-surface energy materials by contrast to conventional polymers and undoped poly(3-octyl thiophene), thus reflecting a behaviour comparable to that of metals or graphite. In the case of polypyrrole, it was found that the dispersive and acid–base properties are correlated, and that the high energetic sites are predominantly acidic. Ageing and low doping levels have a significant impact on polypyrrole surface thermodynamics as they resulted in low surface energy and acidity of this ICP.