Advanced phthalazinone-containing polyarylate nanofiltration membrane performing excellent separation properties and thermal resistance

Chlorine-resistant membranes play a pivotal role in achieving high membrane durability and stable separation efficiency. Inspired by the high oxidative stability of esters, polyarylate nanofiltration (NF) membranes are fabricated using phthalazinone-containing bisphenol monomer, 2,4-(4-hydroxyphenyl)-2,3-phthalazin-1-one (BPPZ), and trimesoyl chloride on the porous substrate via interfacial polymerization. The polyarylate NF membrane exhibits good water flux (51.3 ± 0.9 L m −2  h −1 ) and Na 2 SO 4 rejection (93.6 ± 1.6%), even after exposure to a harsh chlorine environment (200000 ppm h sodium hypochlorite solution). Membrane oxidative stability arose due to ester linkages and strong steric hindrance in the polymeric separative layer, with enhanced chlorine resistance than state-of-the-art chlorine-resistant modified NF membranes. Meanwhile, the polyarylate NF membrane exhibits excellent thermal resistance, achieving a steady operation at 95 °C. This study provides a promising NF membrane with great application potential for treating oxidant-rich water and high-temperature separations.