High-performance PES ultrafiltration membrane with sponge-like structure assisted by N-vinylpyrrolidone

The study focused on the preparation of spongy polyether sulfone (PES) ultrafiltration membrane and investigated the effects of N-vinylpyrrolidone (NVP) and air exposure time on membrane properties. NVP was used as a pore-forming additive to create interconnected pores in the membrane structure, leading to higher water permeability. Furthermore, longer air exposure times generally improved membrane porosity and performance. However, excessive exposure led to membrane shrinkage and reduced mechanical strength. The incorporation of NVP and air exposure effectively mitigates the trade-off effect between permeability and selectivity. this work might provide an effective process for preparing spongy PES ultrafiltration membrane with outstanding antifouling performance, high throughput, and great stability. Therefore, an optimized composite membrane was confirmed by combining the addition of 10 wt% NVP with 40 s air exposure, referred to as M4. The water flux of the M4 membrane reached 797.62 L·m-2·h-1, which was 1.9 times higher than that of a pure PES membrane. Additionally, the rejection rate of bovine serum albumin (BSA) increased from 57.97% to 95.89% compared to the pure PES membrane. The spongy PES ultrafiltration membrane exhibited desirable properties for protein separation and wastewater treatment, making them promising materials for various applications in the field.