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 degrees. The membrane exhibited a high water flux (27.1 LMH) with a low specific reverse salt flux (5.9 x 10(-3) mol L-1) at draw solution concentration of 1 M NaCl at 24 degrees 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.