Enhancing the permeation and antifouling performance of PVDF hybrid membranes by incorporating Co–Fe hydroxide nanoparticles in reverse microemulsion

Abstract

This study attempted to enhance the permeation and antifouling performance of polyvinylidene fluoride (PVDF) ultrafiltration membranes. Reverse microemulsion containing cobalt and iron (Co–Fe) bimetallic hydroxide nanoparticles was blended with the PVDF membranes to construct a novel PVDF hybrid membrane. The permeation performance, antifouling property, and long-term operational stability of the hybrid membranes were evaluated via ultrafiltration process of water flux and bovine serum albumin (BSA) rejection. Structural characterization showed that the protection endowed by reverse microemulsion made the hydroxide nanoparticles to distribute uniformly in the PVDF polymeric matrix. The introduction of well-distributed bimetallic hydroxide nanoparticles substantially improved the pore structures and hydrophilicity of the PVDF hybrid membranes, thereby enhancing their permeation performance and antifouling property. The optimal water flux of the PVDF hybrid membranes (MD-10) reached 328 L·m−2·h−1 and was 5.4-fold higher than that of neat PVDF. Moreover, the MD-10 membrane had a high a high BSA rejection rate (91.04%). After four cycles of successive fouling-cleaning processes, the water flux of the MD-10 membrane still exceeded 160 L·m−2·h−1 and was fourfold higher than that of neat PVDF. However, excessive amounts of the microemulsion could not be uniformly mixed with the PVDF membranes, thereby decreasing the permeation and antifouling performance of the PVDF hybrid membranes.