Magnetite nanoparticles-incorporated composite thin-film nanofiltration membranes based on cellulose nitrate substrate

Thin-film composite nanofiltration membranes were prepared through interfacial polymerization of trimesoyl chloride (TMC), polyvinylpyrrolidone (PVP), and magnetite nanoparticles (MNPs) on the upper surface of porous cellulose nitrate (CN) membranes. Structural and morphological properties of the prepared membranes (CN-TMC/PVP–MNP) were analyzed using FTIR, SEM, membrane contrast and AFM. The effects of reaction time, PVP concentration, and MNPs content on membrane performance were studied. Surface hydrophilicity and membrane performance were analyzed by measuring pure water contact angle, zeta potential, pure water permeation flux (PWP), and solute rejections. The CN-TMC/PVP–MNPs membranes exhibited a smooth surface and diverse surface functionalities following interfacial polymerization. The membrane surface charge was strongly affected by the presence of MNPs. Although PWP decreased with increasing MNPs content up to 0.10 wt%, Na2SO4 and NaCl rejections increased with increasing MNPs content, reaching, respectively, 96.8% and 76.6% at 0.1 wt% MNPs content. Moreover, the increases in steady-state flux and FRRs with increasing MNPs content, reflecting the improvement of antifouling behavior, stability, and durability, indicating their possible application for water desalination and treatment.