High Flux and Antifouling Thin-Film Nanocomposite Forward Osmosis Membrane with Ingrained Silica Nanoparticles

A novel high flux and antifouling thin-film nanocomposite (TFnC) forward osmosis (FO) membrane containing silica (SiO₂) nanoparticles was fabricated using a facile electrospinning technique followed by interfacial polymerization on the surface of an electrospun nanofiber mat. Both the electrospun nylon-6 (N6) substrate and the polyamide (PA) active layer contained superhydrophilic SiO₂ nanoparticles enhancing the hydrophilicity of the fabricated FO membrane. The electrospun N6/SiO₂-supported TFnC FO membrane with a PA/SiO₂ composite active layer was robust (tensile strength of 24.1 MPa) with a water contact angle of 14°. The membrane exhibited a high water flux (27.1 LMH) with a low specific reverse salt flux (5.9 × 10^–3 mol L^–1) at draw solution concentration of 1 M NaCl at 24 °C. The fabricated membrane also showed antifouling propensities for model foulants of sodium alginate and calcium sulfate. After fouling and cleaning operations, the flux recoveries were 98% and 94% (of the initial water flux) for the membranes fouled with sodium alginate and calcium sulfate, respectively. Moreover, a strong interaction between the active layer and the substrate highlighted the structural stability of the fabricated TFnC membrane.