Morphological and adhesive properties of polypyrrole films synthesized by sonoelectrochemical technique

This paper presents sonochemically deposited polypyrrole films and their characteristics of adhesion on substrate with related to the surface roughness and morphology by comparing to the conventional films deposited electrochemically. In particular, the use of high frequency sonication (500 kHz) for sonoelectrochemical deposition of polypyrrole was reported for the first time. Chronocoulometry was used to electrosynthesize polypyrrole films on Si substrates of different thicknesses in order to determine the influence of the polymer thickness on its rugosity, its morphology and its adhesion force properties. The effects of high frequency sonication on the electropolymerized thin film’s properties were investigated using Scanning Electron Microscopy and mechanical probe scanning showing that sonication led to surfaces having a smaller roughness and a better homogeneity than non sonicated ones. The adhesion force properties of polypyrrole films were also studied by means of force-distance curves obtained by Atomic Force Microscopy. For polymer films obtained in the absence of sonication, the measured adhesion forces decreased when the polymer thickness increased. On