Full-Coverage Spongy HEAA/PES Composite Ultrafiltration Membrane with High Selectivity and Antifouling Performances

Selectivity and antifouling of ultrafiltration (UF) membranes are major challenges in the separation and purification of biological proteins. This work reported that full-coverage spongy poly(ether sulfone) (PES) ultrafiltration membranes assisted by the self-cross-linking of N-hydroxyethyl acrylamide (HEAA) were fabricated via a phase inversion method at room temperature. The pore structure of the UF membrane from finger-like to coverage of the spongy structure occurred by increasing the content of HEAA, which is beneficial for size-selective separation of biomolecules. The optimized M4 membrane showed a high surface porosity with a uniform pore size of 30 nm, resulting in more than 99% protein rejection rate for immunoglobulin G (IgG) but less than 20% rejection for bovine serum albumin, confirming that the molecular weight cutoff is 100k Da. Furthermore, the fabricated PES composite ultrafiltration membranes showed excellent antifouling performance and flux recovery efficiency for proteins due to the hydrophilic group of HEAA. This study provides an intelligent strategy for fouling prevention and selective isolation of proteins.