Surface Modification of Polyethersulfone (PES) with UV Photo-Oxidation

Polyethersulfone (PES) films are widely employed in the construction of membranes where there is a desire to make surface more hydrophilic. Therefore, UV photo-oxidation was studied order oxidize PES and increase hydrophilicity. using low pressure mercury lamps emitting both 253.7 184.9 nm radiation were compared with only photons. The modified surfaces characterized X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle (WCA) measurements. Both sets gave similar results, showing an oxygen concentration up saturation level ca. 29 at.% decrease WCA, i.e., hydrophilicity, down 40°. XPS detected sp2 C-C aromatic group bonding formation C-O, C=O, O=C-O, O=C-OH, O-(C=O)-O, sulphonate sulphate moieties. Since little change roughness observed by AFM, oxidation caused