Enhancement of hydrophilicity and the resistance for irreversible fouling of polysulfone (PSF) membrane immobilized with graphene oxide (GO) through chloromethylated and quaternized reaction

A novel graphene oxide (GO) immobilized quaternized polysulfone (PSF) hybrid membrane (Q-PSF/GO) was prepared via phase inversion method using GO as an additive, and triethanolamine (TEOA) as an aminated agent. TEOA, which reacted with both PSF and GO, could improve the dispersibility and compatibility of GO in membrane casting solution. The membrane exhibited highest permeability and rejection rate to bovine serum albumin (BSA) compared to bare PSF membrane and PSF/GO membrane. Expressly, when the same amount of GO was incorporated into the PSF/GO membrane and the Q-PSF/GO membrane, the Q-PSF/GO membrane showed a more satisfactory performance. The water contact angle measurement confirmed the increased hydrophilicity of the Q-PSF/GO hybrid membrane. FE-SEM images proved that the Q-PSF/GO 0.5 membrane possessed larger and more vertical finger-like pore structure in comparison with bare PSF membrane and PSF/GO membrane. Furthermore, it was proved by CLSM images that a thick and incompact layer of BSA was absorbed onto the surface of the Q-PSF/GO 0.5 membrane. However, the absorbed layer of BSA on Q-PSF/GO 0.5 membrane surface could be easily washed away compared to the bare PSF membrane.