Morphological investigation by atomic force microscopy and light microscopy of electropolymerised polypyrrole films

Use of atomic force microscopy (AFM) together with light microscopy (LM) provides an ideal opportunity for studying the initial growth of wrinkles on polypyrrole films. In situ experiments, where continuous AFM image data acquisition was carried out during growth of thin polypyrrole films on indium–tin oxide (ITO) anodes, proved unsuccessful because the height changes occurring during the deposition proved to be too large to handle by the instrument cantilever and fell outside of the range of the z-piezo transducer. However, ex situ experiments have yielded valuable information on the earliest stages of film formation. Parallel in situ experiments where growth was followed by dynamic light microscopy imaging complemented the AFM study to yield a clear picture of the mechanism of formation of wrinkles. Additionally, the experiments confirmed that wrinkles are an integral part of the film and are not an artefact induced in films, consequent to shrinkage or drying out. q 2000 Elsevier Science Ltd. All rights reserved.