Surface glycosylation of polyacrylonitrile ultrafiltration membrane to improve its anti-fouling performance

Surface glycosylation is one of the most promising strategies to fabricate biomimetic surface for membrane. Previous studies confirmed that cyclic sugars provide recognition sites for specific proteins, while ring-opening sugars offer better hydrophilicity and anti-adsorption ability to proteins. To improve the anti-fouling property of polyacrylonitrile (PAN) ultrafiltration membrane, a ring-opening glycomonomer d-gluconamidoethyl methacrylate (GAMA) was grafted onto the surface of the membrane by ultraviolet (UV)-initiated grafting polymerization. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR) and field emission scanning electron microscopy (FESEM) were used to characterize the chemical and morphological changes of the membrane surface. Water contact angle, protein adsorption and protein filtration were employed to evaluate the anti-fouling performance of the membrane. The protein adsorption experiment was carried out with fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA), and the adsorption quantity was measured locally by laser confocal scanning microscope (LCSM). This method supplied a simple and direct manner to evaluate the protein adsorption performance of membrane, and the interference of the support was also avoided. The results revealed that by the surface glycosylation procedure, the hydrophilicity was enhanced and the adsorption of FITC-BSA was inhibited significantly. The flux recovery ratio was also increased after modification, indicating that the anti-fouling performance of PAN membrane was improved by the glycosylation strategy.