Green maltitol-based nanofiltration membranes featuring high permeance and excellent anti-fouling performance for dye desalination

Polyester loose nanofiltration (LNF) membranes are ideal for achieving dye resource recovery. However, the low permeance and insufficient selectivity of dye/salts for polyester membranes remained a significant challenge. This work employed a low reactivity, hydroxyl-rich, non-toxic, inexpensive and renewable, and larger volume green material maltitol (ML) as an aqueous monomer for preparing high-performance polyester membranes. The ML-based membranes had a smooth surface with a considerable negative charge and strong hydrophilicity. The optimized ML-based membranes (ML-1.0/TMC) possessed remarkable water permeance (104.9 L m−2 h−1 bar−1) and excellent dye/salt selectivity (selectivity for CR/NaCl was 340). Additionally, the ML-1.0/TMC membrane demonstrated outstanding stability and excellent anti-fouling performance. The results indicated that the ML-based membranes had excellent performance in dye filtration tests, demonstrating the great potential of ML-based membranes for dye wastewater resource recycling.