Designing high-performance polyethersulfone membranes using the immersion precipitation phase inversion method for various wastewater treatments

The design of multifunctional membranes that integrate high separation performance with long-term stability remains a significant challenge in membrane technology. In this work, small, hydrophilic, and negatively charged nanoparticles are synthesized via oxidative copolymerization of dopamine hydrochloride and L-arginine, and are incorporated as a modifier into polyethersulfone membranes. A non-solvent induced phase separation approach is employed, and the modified membranes exhibit markedly enhanced separation and antifouling performance, together with good cyclic stability, prolonged service life, and noticeable antibacterial activity. At an optimal modifier loading of 0.06 g, the resulting membrane shows a pure water flux of 430.4 L m⁻² h⁻¹, and achieves retention rates of 99.9% and 99.7% for bovine serum albumin and Congo red, respectively, while retaining 74.8% of methylene blue. The nanoparticles also display excellent compatibility with the polyethersulfone matrix, which underpins the membrane's stable cycling performance and durability. In summary, these nanoparticles not only enhance both the separation performance and the operational stability of polyethersulfone membranes, but also enhance their adaptability to complex aqueous environments. This approach paves the way for high-performance, multifunctional membranes, with potential applications spanning from water treatment to other separation technologies.