UV-assisted interfacial polymerization enables nanofiltration membranes with enhanced permeance and anti-fouling performance

Regulating the nanofiltration (NF) membrane structure for the simultaneous improvement in permeance and selectivity has attracted extensive attention. In this study, ultraviolet (UV) irradiation was integrated in situ into a typical interfacial polymerization (IP) process to modulate the IP reaction precisely and thus modify the microscopic architecture of NF membranes. UV irradiation was capable of activating trimesoyl chloride (TMC) and inducing photothermal effects. The optimized NF membranes presented thinner and rougher surfaces, as well as an increased negative charge and hydrophilicity. Compared with the control NF membrane (NFM-Con), the optimized NFM-UV40 achieved excellent performance, with 35.5 % greater water permeance and 186.6 % greater Cl⁻/SO₄²⁻ separation selectivity. Notably, the UV-assisted NF membranes had better anti-fouling properties than those of commercial NF270. This study proposes a novel strategy for the precise in situ regulation of NF membrane structure and performance, enabling the development of high-performance separation membranes for NF-based water desalination.