Metal–organic framework ZnL–PVDF supramolecular ultrafiltration membrane for enhanced separation performance

Abstract

Using an in-situ chemical blending method, ZnL–polyvinylidene fluoride (PVDF) supramolecular ultrafiltration (UF) membranes were fabricated to solve the problem of agglomeration of metal–organic frameworks (MOFs) in MOF/polymer UF membranes. In this process, the MOF material, ZnL, was directly synthesised during preparation of the PVDF casting solution and ZnL–PVDF supramolecular membranes were fabricated by phase inversion. With the increase of ZnL, the pure water flux of the membrane initially increased sharply and then decreased slowly, accompanied by an almost identical trend in bovine serum albumin (BSA) rejection. In particular, the fabricated membrane (with ZnL content of 15 wt%) possessed a water flux up to 271.8 L m−2 h−1 bar−1, nearly six times that of the pristine PVDF membrane, and high BSA rejection of 96.5%. These results indicate that the facile in-situ chemical blending method is promising for fabricating uniform and highly hydrophilic MOF/polymer UF membranes.