Physical properties of polypyrrole films containing trisoxalatometallate anions and prepared from aqueous solution

Polypyrrole (PPy) thin films containing trisoxalatometallate anions (M(ox)33−, M = Cr and Al; ox = C2O42−) were prepared electrochemically from aqueous solution in a single-compartment cell. Thicknesses were in the range 30–70 μm. They were characterized by elemental analysis and diffuse specular reflectance FT-IR spectroscopy. Their structural and morphological features were probed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Room-temperature electrical conductivities (11–50 S cm−1) were comparable to those of the well-studied PPy–p-toluenesulfonate system. Some limited studies of the effect of oxygen and nitrogen on the variation of conductivity with time were made. Some of the films displayed excellent conductivity stability over a period of 50 days, comparable to the stability found in other commonly reported polymers.