Water-soluble MOF nanoparticles modified polyethersulfone membrane for improving flux and molecular retention

Abstract The design and preparation of polymeric membranes with excellent permeability while maintaining the high rejection remains a great challenge. In this study, water-soluble metal-organic framework nanoparticles are fabricated and used as additive for modification of polyethersulfone membrane to form a uniform porous membrane by liquid-liquid phase conversion technology. The water-soluble metal-organic framework nanoparticles can be removed by water dissolution, which is beneficial to form a thin and porous separation layer on the modified membrane. And we can control the amount and size of pores in the modified membrane by changing the concentration and size of the metal-organic framework nanoparticles. Therefore, permeability of the modified membrane is significantly improved. When the mass fraction of metal-organic framework nanoparticle is 3%, the water flux of the modified membrane is up to 121.5 L m−2 h−1, and has a high rejection close to 100% for bovine serum albumin. The rejection rates of modified membranes for methyl blue and congo red are 82.3 and 98.6%, respectively. Our work provides a simple method to fabricate an advanced modified membrane with outstanding separation performance.