Construction of PES mixed matrix membranes incorporating ZnFe2O4 @MXene composites with high permeability and antifouling performance

ZnFe2O4@MXene composites were first prepared through the coprecipitation method to enhance the permeability and antifouling properties of polyether sulfone (PES) ultrafiltration membranes. Subsequently, the ZnFe2O4@MXene composites were blended with PES to construct mixed matrix membranes (MMMs) with good permeability and antifouling performance. Results show that the deposition of bimetallic ZnFe2O4 on the surface or in the interlayer structure of Ti3C2Tx laminates resulted in strong interactions between the materials, thus improving the dispersion of the ZnFe2O4@MXene composites in the PES polymer. The addition of well-distributed ZnFe2O4@MXene composites not only improved the pore structure of the MMMs but also enhanced the hydrophilicity and surface polarity of the MMMs because of the rich hydrophilic groups on the surfaces of the ZnFe2O4@MXene composites. The permeability and antifouling performance of the resulting MMMs were thus improved. When additional ZnFe2O4 nanoparticles were uniformly deposited on the surface or in the interlayer structure of the Ti3C2Tx lamellar structures, the hydrophilic groups on the surfaces of the ZnFe2O4@MXene composites increased. Therefore, using these composites as fillers significantly enhanced the permeability and antifouling performance of the resulting MMMs. The PES MMMs exhibited a maximum membrane flux of 492.8 L∙m−2·h−1 and a maximum bovine serum albumin (BSA) rejection rate of 92.5%. Their membrane flux could be maintained at approximately 350 L·m−2·h−1 over five cycles of BSA solution/backwashing. This result reflects the high stability of the membranes. In addition, UF-4 achieved the highest flux (324.56 L∙m-2∙h-1) and a high dye/salt separation (RCR = 97.3; RNa2SO4 = 8%), confirming that PES MMMs containing ZnFe2O4@MXene have good application prospects for the separation of dyes from high-salinity wastewater.