Nanofiltration Membrane via Organic Nanoparticle-Assisted Interface Polymerization for Efficient Dye/Salt Separation

Abstract

Nanofiltration membranes have the advantages of high flux and good selectivity, making them ideal materials for solving water resource pollution and scarcity; however, the mechanism of interface polymer membrane wrinkling induced by nanofillers is not clear, and the low flux of interface polymer membranes is a pressing issue for researchers. In this work, superhydrophilic l-histidine-modified nanoparticles are successfully synthesized and added to the interface polymerization process, where the nanoparticles also participate in the interface polymerization reaction, inducing interface polymerization. The formation of layered wrinkles on the membrane surface greatly increases the contact area of the membrane surface and enhances the hydrophilicity. The water contact angle on the membrane surface decreases from the original 51.85 to 28.72°. When the modifier-modified dopamine particles are added at a concentration of 0.1 wt %, the water permeance of the nanofiltration membrane reaches 145.57 L m^–2 h^–1 MPa^–1, with a dye rejection rate of over 99% and high permeability to inorganic salt ions, confirming that the membrane can be used for efficient dye/salt separation. Furthermore, the stability of the membrane is improved, greatly enhancing its practical applicability.