Abstract
Plasma treatment is an efficient method to modify organic surfaces. In this work electrospun polyphenylsulfone was systematically subjected to low-pressure microwave plasma and atmospheric-pressure coplanar barrier discharge in order to control the surface chemistry, which is important for controlling surface properties. Polar anchor groups such as keto/aldehyde groups and especially carboxylic acid groups affect hydrophilicity. The composition of plasma-induced chemical anchor groups can be monitored (and thus controlled) by X-ray photoelectron spectroscopy. The atmospheric-pressure plasma provided subtle oxidation, and the low-pressure plasma provided significant oxidation that resulted in polyphenylsulfone surfaces with a very high hydrophilicity. The low-pressure plasma treated polyphenylsulfone exhibited a significant age effect over 212 days, which was attributed to a diffusion phenomenon where the polyphenylsulfone surface becomes enriched in non-oxidated polyphenylsulfone. It was shown that the improved hydrophilicity will diminish but not vanish in time.