Reducing fouling of polyethersulfone microfiltration membranes by corona air plasma

Abstract

In this study, the surface of polyethersulfone (PES) microfiltration membranes was modified by corona discharge plasma in order to improve the antifouling properties and separation performance of the membranes. For this purpose, the PES microfiltration membranes were fabricated by the vapor-induced phase inversion coupled with the nonsolvent-induced phase inversion technique. The effect of the corona power and exposure time on the surface properties and separation performance of the membranes for microfiltration of skim milk was studied. The analysis of the filtration transport resistances was also performed to evaluate the antifouling performance of the corona-modified membranes. The results indicated that the exposure time and applied power of the corona treatment had effects on the membrane surface modification as the surface hydrophilicity, wettability, and morphology of the membranes were significantly changed depending on the corona modification conditions. Moreover, the analysis of the transport resistances revealed that the cake resistance was the main resistance to transport and the fouling, cake and total filtration resistances for the corona-modified PES membranes were low in comparison to the neat PES membranes, which implies that the fouling tendency of the PES membranes modified by the corona air plasma was considerably reduced.