Synthesis and characterization of novel zwitterionic poly(aryl ether oxadiazole) ultrafiltration membrane with good antifouling and antibacterial properties

Notably, zwitterionic polymers have attracted increasing attention to various potential applications in membrane-based separation processes on account of the good biocompatibility, superior antifouling and excellent antimicrobial property. In this contribution, a novel membrane material based on zwitterionic poly(aryl ether oxadiazole) (Z-PAEO) was designed and synthesized by a facile and convenient two-step route consist of polycondensation and quaternary amination reaction. Z-PAEO ultrafiltration membrane was subsequently fabricated by the scalable non-solvent induced phase separation (NIPS) method. The chemical structures and compositions of these prepared polymers were determined by using 1H NMR, FTIR and XPS measurements, and their inherent viscosities, molecular weights, thermal properties and solubility behaviors were extensively characterized, respectively. The presence of zwitterionic groups considerably improved the porosity, pore size and hydrophilicity of Z-PAEO membrane, which was helpful to the permeability of the obtained membrane without obviously affecting the protein rejection. Interestingly and significantly, the as-prepared Z-PAEO membrane displayed superior and persistent antifouling performance as well as antibacterial property. The water flux recovery ratio of Z-PAEO membrane (97.6%) after a three-cycles of BSA solution filtration was much higher than that of the reference PAEO membrane (78.4%), suggesting excellent long-term performance stability. It can be expected that developing novel zwitterionic polymers can significantly expand the application scopes of separation membrane.