ESCA and TOF-SIMS study on oxidised and reduced polypyrrole-poly(4-styrenesulfonate) free-standing films synthesized on Ti electrodes

Thin films of polypyrrole, composited with poly(4-styrenesulfonate), formed electrochemically on titanium plate electrodes could be peeled off readily as free standing films, before and after reduction in the aqueous forming solution. Both surfaces (electrolyte side and electrode side) of such free standing films had been investigated using electron spectroscopy for chemical analysis (ESCA) and time of flight secondary ion mass spectrometry (TOF-SIMS). The morphologies for the electrolyte sides of both oxidized and reduced forms of such polypyrrole composite films were clearly different from those of the electrode sides, but little difference in surface conductivity between the two sides of each form was detectable using the four-point probe technique. ESCA spectra showed high sodium ion presence on the surfaces of the reduced form but not detectable on the surfaces of the oxidized form. Secondary electron images and ion maps of sampled areas on the films from the TOF-SIMS study revealed some interesting surface features.