Monovalent anion-selective membranes fabricated via in situ interfacial polymerization

作者：Noor Ul Afsar, Michael Holmboe, C. André Ohlin, Niaz Ali Khan, Liang Ge, Tongwen Xu, Naser Tavajohi · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-64196-2 · 被引用次数：7 · 研究领域：Fuel Cells and Related Materials、Membrane-based Ion Separation Techniques、Advanced Battery Materials and Technologies

Abstract Developing monovalent anion-selective membranes (MAPMs) faces challenges, including the trade-off between flux and selectivity, membrane stability, and cost-effective fabrication. Overcoming these requires advanced material design and scalable techniques. Here, we introduce in situ interfacial polymerization (ISIP) to prepare MAPMs. Base membranes are synthesized via superacid polymerization and modified with anion channels and -NH 2 groups. During ISIP, trimesoyl chloride reacts with surface -NH 2 groups, forming a partially crosslinked structure with -COOH groups to regulate ion transport via electrostatic interactions. This results in low membrane resistance (4.7 Ω cm 2 ) and selective transport of weakly hydrated ions (Cl − , Br − , NO 3 − ), while strongly hydrated ions (SO 4 2 − , F − ) face higher barriers. MAPMs demonstrate high performance, achieving a limiting current density (>90 mA cm − 2 ), Cl − flux (1.98 mol m − 2 h − 1 at 5 mA cm − 2 ), and selectivity (244 for Cl − /SO 4 2 − ), confirming effective hydration dynamics control and balanced performance. Simulations reveal how charge distribution affects ion migration pathways.