Scanning tunneling microscopy (STM) and lateral force microscopy (LFM) investigation of the structure and character of conductive polypyrrole film

Abstract

Polypyrrole doped with p-toluenesulfonate was electropolymerized onto highly oriented pyrolytic graphite (HOPG), glassy carbon (GC) and Pt electrode surfaces under the same experimental conditions. The resulting films were studied by scanning tunneling microscopy (STM) and lateral force microscopy (LFM). It is found that the topography of these thick films on HOPG, GC and Pt is very similar although their substrate surface morphology is completely different. Furthermore, the microstructure of these films generally transforms from disordered, amorphous and flocculent particles to ordered, homogeneous and oriented granules on exposure to air. In addition, the effect of different ions on surface morphology and the thermal stability of the polypyrrole films are also discussed in detail.