Characterization of Polymer Films of Pyrrole Derivatives for Chemical Sensing by Cyclic Voltammetry, X-ray Photoelectron Spectroscopy and Vapour Sorption Studies

Abstract

Eight different conducting polymer films formed from pyrrole and N-substituted pyrrole derivatives were characterized by cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy. In particular, the XPS of poly[N-butylpyrrole], poly[N-(2-carboxyethyl)pyrrole], poly[N–(6–hydroxyhexyl)pyrrole] and poly[N-(6-tetrahydropyranylhexyl)pyrrole] is reported for the first time. The vapour sorption properties of these films were also examined by forming the films onto the electrodes of thickness-shear mode acoustic wave sensors. The influence of the pendant side chain is apparent in both the electrochemical behaviour, composition, doping level, morphology and the nature and extent of polymer–vapour interactions. The latter can be rationalized by consideration of vapour physical properties and solvatochromic parameters.