Thermal-modulated interfacial polymerization towards chlorine-resistant and dense polyester NF membranes for healthy drinking water

Low-pressure, chlorine-resistant polyester (PE) nanofiltration (NF) membranes achieving superior organic matter/mineral selectivity are a promising candidate for producing healthy drinking water. However, PE-based NF membranes are mostly loosely structured, and less effective in removing natural organic matter. In this work, a maltitol monomer with a distorted non-planar structure was used to precisely regulate the properties of PE-based dense NF membranes (DNF) by thermal-modulated interfacial polymerization (TIP). The TIP contributed to the fast formation of a dense and highly crosslinked PE network on the support. The prepared DNF membranes were highly hydrophilic and electronegative. The non-volatile Isopar G was chosen as an organic solvent to minimize the nanobubble effect on PE membrane surface roughness, resulting in a relatively smooth membrane surface. The optimized Maltitol@PE6.5 membrane exhibited satisfactory water permeance (15.7 L m⁻² h⁻¹ bar⁻¹), DOC rejection (79.6 %), and outstanding chlorine resistance (48,000 ppm h). This study provides a new strategy for tailoring high-performance PE-based DNF membranes to treat natural surface water for healthy drinking water.