Sugar-based membranes for nanofiltration

Sugar-based nanofiltration membranes were successfully developed through a facile interfacial polymerization reaction. Glucose, maltose and raffinose, representing the most classic mono-, di- and tri-saccharides, were used as the aqueous monomers to react with trimesoyl chloride. Importantly, NaOH was utilized to accelerate the reaction between acyl chloride groups and the lowly active hydroxyl groups, forming a dense polyester separation layer. The optimal sugar-based membrane shows a high water permeance of 33.7 ± 1.4 L m⁻² h⁻¹ bar⁻¹ and a Na₂SO₄ rejection of ~95%, demonstrating the potential of rapid desalination. Systematic characterizations by chemical analyses and optical microscopy were carried out. The results revealed that the high separation performance of the sugar-based membrane mainly benefited from its negatively charged, hydrophilic surface and super thin polyester layer. Considering the sustainable and green nature of saccharides, the sugar-based membrane is promising to stand out in the next-generation membrane field. Our findings enlighten the development of sugar as bio-monomer in fabricating high-performance nanofiltration membranes.