In situ formation of nanoparticles of silver, copper, and iron and nanocomposite membranes fabricated via interfacial polymerization

Advanced membrane technologies with enhanced antifouling resistance and long-term stability are crucial for addressing the escalating issues of water pollution and resource scarcity. In this work, silver (Ag), copper (Cu), and iron (Fe) nanoparticles were systematically incorporated over a polysulfone (PSF) membrane via in situ reduction within a polyethyleneimine (PEI) layer, followed by interfacial polymerization using trimesoyl chloride (TMC). Unlike previous studies that evaluate individual metals in different polymer systems, this study provides a direct comparative assessment of Ag, Cu, and Fe within the same PSF–PEI–TMC composite, enabling clear evaluation of metal-specific effects on membrane performance and stability. Nanoparticle incorporation significantly modified surface wettability, pore structure, and roughness relative to pristine PSF. Iron-embedded membranes exhibited the highest pure water permeance (up to 276.46 LMH/Bar), representing more than a twofold increase compared to PSF; however, they showed the poorest antifouling performance due to strong protein–metal interactions. Silver-modified membrane achieved the highest COD rejection (17.44%) among all but suffered from substantial nanoparticle leaching (up to 370.4 µg/m 2 h), limiting their long-term applicability. In contrast, copper-embedded membranes demonstrated a balanced performance, demonstrating an antifouling performance with flux recovery ratio of 82.02% with negligible metal leaching while maintaining enhanced permeability compared to pristine PSF. These findings demonstrate that although Ag improves rejection and Fe enhances flux, in situ copper nanomaterial provides the optimal performance between permeability, fouling resistance, and environmental stability.