Fabrication of MIL-53(Al)-Incorporated Cellulose Acetate Mixed Matrix Forward Osmosis Membrane for Seawater Desalination

Forward osmosis (FO) membranes have received growing attention in the field of water treatment. Nevertheless, their practical application in seawater desalination remains restricted, underscoring the imperative of developing advanced membrane modification techniques. In this study, we synthesized metal–organic framework MIL-53(Al) nanoparticles via a hydrothermal method and incorporated them into cellulose acetate (CA) membranes to fabricate a CA/MIL-53(Al) mixed-matrix FO membrane. The synthesized MIL-53(Al) nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption analysis. The effects of MIL-53(Al) loading, pore-forming agent content, mixing temperature, and coagulation bath temperature on the membrane performance were systematically investigated to optimize the fabrication conditions. Under the optimal conditions, the prepared CA/MIL-53(Al) mixed matrix FO membrane exhibited a water flux of 65.71 L/(m2·h) and a reverse salt flux of 2.20 g/(m2·h). Compared with the pristine CA FO membrane, the incorporation of MIL-53(Al) significantly improved the membrane permeability and separation performance. These enhancements were attributed to the improved hydrophilicity and optimized membrane structure induced by MIL-53(Al) nanoparticles. This study demonstrates that MIL-53(Al) is an effective nanofiller for the fabrication of high-performance CA-based FO membranes and provides a promising strategy for seawater desalination applications.