Surface characterization of Langmuir-Blodgett polypyrrole films obtained by a solid-state reaction

We have examined polypyrrole obtained by a solid reaction from a ferric stearate Langmuir-Blodgett film by means of X-ray photoelectron spectroscopy, static secondary ion mass spectrometry and scanning electron microscopy. These surface-specific techniques enable us to probe the surface composition of the conducting polymer. All the analyses show the presence of the polypyrrole at the surface. The morphology of the samples appears to be formed by small clusters of polymer with dimensions in the range 50–300 nm in a stearic acid matrix with a quite porous surface. Moreover, by measuring the specimen current, we observe that, in accordance with polypyrrole clusters, the current value is higher with respect to the remaining film; this result further confirms the formation of the conducting polymer.