Surface Modification of the Polyimide Films by Electrical Discharges in Water



Pulsed electrical discharges in distilled water were used for the surface modifications of the aromatic polyimides. Optical emission spectroscopy has shown the formation of excited species in the plasma due to water dissociation and ionization. The reactive species have induced surface modifications of the polymer films which were investigated by FTIR, AFM, XPS, and static contact angle measurements. The surface hydrophobicity of the polyimide films increased with the plasma treatment time due to the segregation of the CF3 groups at the polymer surface and the imidization of the polyimides during the plasma discharge. ppap201300015-gra-0001