Xylitol-based polyester loose nanofiltration membranes with outstanding water permeance and efficient dye desalination performance

Polyester (PE) membranes with outstanding permeance and efficient dye desalination performance have become ideal for resource recovery from dye wastewater. However, further improving the performance of PE membranes remains challenging. Herein, a novel high-performance PE loose nanofiltration (LNF) membrane was fabricated via interfacial polymerization, in which nontoxic, rich in hydroxyl, large size, inexpensive, low reactivity, and biodegradable xylitol (XL) was utilized to fabricate PE films. The newly formed XL-based membrane had a hydrophilic, negatively charged, smooth, loose, and thin selective layer. The membrane was optimized by controlling the XL concentrations in the aqueous phase (0.5–2.5 wt%). The optimized membrane (XL-1.5/TMC) exhibited unprecedented water permeance (97.6 L m−2h−1 bar−1) and satisfactory dye desalination performance (Congo red/Na2SO4 selectivity of 259). In addition, the XL-1.5/TMC membrane showed outstanding antifouling performance and stability, which showed great potential for the large-scale application of XL-based membranes. Therefore, this new strategy for the fabrication of PE LNF membranes featuring superior performance using XL was proposed to facilitate resource recovery from dye wastewater.