Thin-Film Composite Polyamide Membranes with In Situ Attached Ag Nanoparticles for Fouling-Mitigated Wastewater Treatment

Abstract

As an ideal membrane for wastewater treatment, desirable separation performance, and fouling resistance are both requisite. Herein we directly in situ attached Ag based nanoparticles on the surface of thin-film composite polyamide (TFC PA) membranes by using benzenediamine (BDA) derivatives with acid functional groups as one aqueous monomer mixed with m-phenylenediamine (MPD) for interfacial polymerization (IP). The acid functional groups in BDA derivatives incorporated in the PA layer facilitated the in situ metallization or mineralization without grafting additional “bridge” linkers. Various characterization techniques were employed to elucidate the modification mechanism. The effects of molecular structures of BDA derivatives on the surface properties, separation performance, and antifouling capacity of resulting membranes were also systematically investigated. Compared with the pristine TFC membrane, the modified membranes exhibited the 85.83% water flux enhancement and 65.25% lower reverse salt flux overcoming the permeability-selectivity trade-off. Moreover, the total Ag loading of modified membranes increases by 8–14 times as compared to that of the pristine one, thereby the enhanced antibacterial and antifouling capacities in wastewater treatment.