Development of high-flux reverse osmosis membranes with MIL-101(Cr)/Fe₃O₄ interlayer

MIL-101(Cr) has a special pore cage structure that provides broad channels for the transport of water molecules in the reverse osmosis (RO) water separation and purification. Combining MIL-101(Cr) with Fe₃O₄ nanoparticles forms a water transport intermediate layer between the polyamide separation membrane and the polysulfone support base under an external magnetic field. MIL-101(Cr) is stable in both water and air while resistant to high temperature. With the introduction of 0.003 wt.% MIL-101(Cr)/Fe₃O₄, the water flux increased by 93.31% to 6.65 L·m⁻²·h⁻¹·bar⁻¹ without sacrificing the NaCl rejection of 95.88%. The MIL-101(Cr)/Fe₃O₄ multilayer membrane also demonstrated certain anti-pollution properties and excellent stability in a 72-h test. Therefore, the construction of a MIL-101(Cr)/Fe₃O₄ interlayer can effectively improve the permeability of RO composite membranes.