Surface modification of polycarbonate and poly(ethylene terephthalate) films and membranes by polyelectrolyte deposition

The surface modification by chemical or physical adsorption of a polyelectrolyte (polyallylamine, PAH) was established using hydrolyzed polycarbonate (PC) and poly(ethylene terephthalate) (PET) thick and thin films. Contact angle data indicated changes in the hydrophilicity of PET film surfaces in terms of the chemical treatment. XPS analysis showed that the immobilization of PAH on PET and PC films was effective and that the amount of chemically or/and physically bounded PAH depends on the pH of the electrolyte solution used for the adsorption. Similar treatments have been successfully applied to polymeric track-etched membranes. These modified membranes have been used as templates for the synthesis of polypyrrole (PPy) nanotubules. FE-SEM analysis showed that much thicker PPy tubules were obtained in modified membranes than in virgin ones. This indicates that the surface chemistry of the pore walls plays an important role in the morphology of the nanostructures synthesized within the pores.