A novel antifouling and thermally stable polysulfone ultrafiltration membranes with sulfobetaine polyimide as porogen

Polysulfone ultrafiltration membranes were prepared with sulfobetaine polyimide (s-PI) via phase inversion process, during which s-PI migrated and enriched on the surfaces of membranes/pores due to its hydrophilic nature. Therefore, s-PI not only enhanced surface hydrophilicity, but also acted as a pore-forming agent. It was proved that the introduction of s-PI effectively promoted membrane porosity and antifouling ability. Under optimized conditions, the pure water flux of blend membranes reached 220.58 L m(-2) h(-1) with a protein rejection ratio of 99.3%, and a flux recovery ratio of 90.86%, indicating the superior antifouling property and filtration performances of zwitterionic polymer blend membranes. Moreover, the blend membrane can stand a temperature of 90 degrees C without degrading its separation performance. Besides excellent thermal stability, the blend membranes exhibited a distinctly advanced mechanical strength due to the addition of rigid s-PI polymer. Overall, this study provided a facile and scalable method for the preparation of antifouling and thermally stable ultrafiltration membranes.

Automated summary

Ultrafiltration membranes prepared with sulfobetaine polyimide (s-PI) exhibited superior antifouling and filtration performances, with a pure water flux of 220.58 L m(-2) h(-1) and a protein rejection ratio of 99.3%. Additionally, the blend membranes showed excellent thermal stability and mechanical strength, maintaining separation performance at 90 degrees C.