Surface modification of high-rejection ultrafiltration membrane with antifouling capability using activated oxygen treatment and metallic glass deposition

Abstract

Polysulfone (PSf) composite ultrafiltration membranes were subjected to Ar/O2 plasma assisted oxygen activation and then coated with various forms of metallic glass (W50Ni25B25, Zr60Cu25Al10Ni5, and Pd74Si14Cu12). The activated oxygen treated PSf ultrafiltration membrane was strongly hydrophilic, with pure water flux (PWF) of 350.7 L m−2 h−1 and bovine serum albumin (BSA) rejection of 83%. The application of metallic glass (MG) to the surface of the polysulfone composite membrane using low-power radio-frequency magnetron sputtering improved the BSA rejection rate (ranging from 98.6 to 99.9%) with only a slight reduction in PWF: tungsten-based MG (321.5 L m−2 h−1), zirconium-based MG (215.6 L m−2 h−1), and palladium-based MG (181.3 L m−2 h−1). The membrane with the tungsten-based coating achieved remarkable PWF, BSA rejection, and antifouling performance, due primarily to high surface hydrophilicity (water contact angle of 24.2°) and a strongly negative surface charge. Overall, the proposed metallic glass/polysulfone composite membranes achieved moderately high PWF and protein rejection with incredible antifouling competence, even under extended (multi-cycle) fouling conditions.