Polypyrrole film modified with electroless metal deposition

Electroless deposition of ruthenium was achieved on polypyrrole coated copper. The effect of ruthenium particles have been investigated on electronic/ionic conductivity properties of polypyrrole film, in relation with morphology and stability of polymer film. Atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and electrochemical impedance spectroscopy (EIS) techniques were utilized. Dependence of surface capacitance on DC polarization was investigated to understand electronic conductivity behaviour of coating. The synthesis parameters affected electronic conductivity behaviour, as well as ionic mobility through the film. Thus, the electrochemical interaction with substrate became totally different, and then the protection mechanism and efficiency changed remarkably. Less degraded polypyrrole film exhibited regular p-type semiconductor behaviour, in aqueous environment. Ruthenium modification did not change this property but had negative effect on oxidation-reduction behaviour of polymer film, decreasing ionic mobility. The anticorrosive property of polymer film has changed significantly in relation with structural diversities caused by synthesis procedure and further modification. (C) 2011 Elsevier B.V. All rights reserved.