Tuning the microstructure of SMA/CPVC membrane for enhanced separation performance by adjusting the coagulation bath temperature

Abstract In this study, styrene‐maleic anhydride copolymer/chlorinated polyvinyl chloride composite membranes were prepared via a non‐solvent induced phase separation technique. Different porous morphologies of the composite membranes were obtained by controlling the temperature of coagulation bath water. With the coagulation bath temperature increasing, the porous morphology of membrane surface changed from co‐continuous pores to isolated‐round‐pores, and its evolution mechanism was elaborated. The average pore size of membranes surface increased from 17.27 to 48.72 nm, the pure water flux increased from 225.50 to 624.47 L m −2 h −1 , and the rejection rate of Congo red and bovine serum albumin declined gradually with the increase of coagulation bath temperature, but the NaCl rejection was less than 1.0%. The surface segregation behavior of anhydride groups was affected by the phase separation process, which in turn affects the anti‐fouling performance of membranes. The composite membranes obtained at the coagulation bath temperature of 20 and 30°C had large surface segregation of anhydride groups and excellent anti‐fouling performance. The water flux recovery rate is higher than 90% and the irreversible pollution decline rate is about 5.0%. Meanwhile, the obtained membranes, especially the membrane fabricated at a coagulation bath temperature of 0°C, has good dye/NaCl salt separation performance and can be used for the pretreatment of textile wastewater.