Preparation and Characterization of Polyamide Thin Film Composite Nanofiltration Membrane Based on Polyurethane Nanofibrous Support

Polyurethane nanofibers recognized to perform as a sub-layer were employed herein as a medial-layer of high porosity in the fabrication of a novel class of thin-film nanofiltration membranes. In line with the primary aim of high throughput production of PU electrospun nanofibrous membranes (ENMs) with different fiber sizes and proper morphologies, the needle-free electrospinning technique was employed. An interfacial polymerization procedure was also utilized to conveniently coat a polyamide (PA) thin film on the polyurethane ENMs. The effects of the nanofibrous interconnecting network, fiber size, pore size, and morphology on the NF performance were investigated. The nanofiltration performance including the separation of various salts, water flux, and the MWCO test were performed. The results implied that the fiber size decrement, nanofibers interconnection increment, as well as nanofibrous membrane pore size decrement, and the nanofibrous layer increment (with different fiber size) would lead the interfacial polymerization to perfection and obtaining a uniform PA thin layer. The salts rejection and water flux of Na2SO4, MgSO4, MgCl2 and NaCl were (~ 99 ± 0.5 %, 37 ± 2.7 L/m2h), (~ 98 ± 1 %, 40 ± 1.5 L/m2h), (~ 95 ± 2 %, 33 ± 2 L/m2h) and (~ 52 ± 1 %, 30 ± 3 L/m2h), respectively. In the final analysis, a comparison of filtration performance between PU nanofibrous NF membranes with other well-known nanofibrous NF membranes was conducted.