Interfacial polymerization combined with etching: A novel surface modification method for ultrafiltration membranes

This study presents a novel surface modification method for ultrafiltration membranes via interface polymerization combined with etching, with the objective of enhancing their separation performance and antifouling properties. Polyethersulfone (PES) ultrafiltration membranes were modified via interfacial polymerization of polyethylene glycol (PG) with trimesoyl chloride (TMC) to form a polyester separation layer. This was followed by alkaline etching, which served to remove the majority of the polyester layer, leaving a residual portion that was then employed to modify the membrane surface. The modified membranes displayed enhanced hydrophilicity and a diminished surface charge, which resulted in an elevated level of antifouling performance. The successful modification of the membranes was confirmed by physicochemical characterizations, including scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and contact angle measurements, which also demonstrated an enhanced hydrophilicity. The results of the separation performance tests demonstrated that the modified membranes retained their original separation properties while exhibiting enhanced flux recovery rates following the introduction of fouling cycles. The results of the long-term stability tests demonstrated that the modified membranes retained their performance over an extended period, indicating their potential for practical applications. The findings of this study offer a promising approach to enhancing the performance of ultrafiltration membranes in industrial separation processes.