A facile route to non-polyamide nanofiltration membranes with layered double hydroxide nanofillers for enhanced dye rejection and antimicrobial performance

We report the facile fabrication of a non-polyamide (non-PA) nanofiltration membrane via a glutaraldehyde (GA)–m-phenylenediamine (MPD) interfacial polymerization (IP) process and its modification with CuFeCe-layered double hydroxide (LDH) nanofillers for enhanced dye rejection and antibacterial performance. The reaction between GA and MPD produced a loose and hydrophilic selective layer with tunable pore structures, optimized by adjusting GA concentration, MPD content, reaction time, and post-treatment temperature. The incorporation of LDH significantly improved membrane hydrophilicity and permeability, with the optimum composition (NPM2, 0.25 wt% LDH) achieving a pure water flux of 148 LMH/bar and 95–99% rejection for dyes while maintaining low Na₂SO₄ rejection (∼8.5%). The enhanced performance was attributed to the synergistic effects of improved surface wettability, increased roughness, and uniform LDH dispersion within the membrane matrix. Furthermore, the LDH-modified membrane exhibited notable antibacterial activity against E. coli , confirming its potential for mitigating biofouling. Overall, the proposed non-polyamide mixed matrix membrane offers a sustainable and scalable approach for high-flux dye rejection with low salt rejection, along with antimicrobial functionality for water treatment applications.