Fabrication of antifouling membrane surface by poly(sulfobetaine methacrylate)/polydopamine co-deposition

Poly(sulfobetaine methacrylate) (PSBMA) has been widely employed for the surface modification of membranes due to its excellent antifouling property. However, challenges still remain to simplify the modification processes and to increase the utilization efficiency of PSBMA (or sulfobetaine methacrylate, SBMA). In this paper, a simple one-step co-deposition process is introduced to fabricate antifouling surfaces for microporous polypropylene membranes (MPPMs) based on the self-polymerization and high adhesion properties of dopamine with the hydrophilicity of PSBMA. Meanwhile, the effect of PSBMA concentration on the membrane surfaces was studied in detail by ATR/FT-IR, XPS, and FESEM. Significant improvement is demonstrated for the surface hydrophilicity by results of water contact angle and pure water flux. Dynamic protein filtration experiments confirm the excellent antifouling property of the resulted membranes. Furthermore, the utilization efficiency reaches 9.13 wt% for PSBMA, 10 times higher than that of SBMA for UV-induced grafting on MPPM. In conclusion, the one-step modification method provides a simple and effective approach to construct antifouling surfaces for membranes.