Distribution analysis of TiO2 and commercial zinc phosphate in polypyrrole matrix by XPS

TiO2 as well as a commercial zinc phosphate pigment were incorporated to the PPy matrix during its electropolymerisation on mild steel. Their distribution in the composite films (PPy/TiO2 and PPy/zinc phosphate) was examined by X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy (SEM). Chemical and electrochemical factors had different influences on their distribution within the PPy matrix. XPS analysis showed that TiO2 is found throughout the PPy films and it is uniformly distributed onto the surface, conversely to zinc phosphate. The latter is present in two heterogeneously distributed forms; (1) a conductive soluble minority and (2) a non-conductive non-soluble majority. The minority form is probably inserted from the soluble species in a complexed form and plays a counter-ion role.