Interfacial Polycondensation Kinetics Regulation Enables Microporous Polyesteramide Membranes for Ultraselective Water Purification

Membrane nanofiltration (NF) offers a compelling avenue for energy-efficient water purification, but the coordinated control of microporosity and oxidation resistance of polyamide (PA) NF membranes remains challenging. Here, a generalizable plant polyphenol-regulated interfacial polymerization (PP-RIP) was demonstrated to construct microporous polyesteramide (PEA) membranes with refined chemical and structural features for the selective removal of organic micropollutants (OMPs). In PP-RIP, the piperazine alkaline solution promotes the deprotonation of polyphenol, overcoming its limited reactivity. The resulting high-polarity deprotonated polyphenols not only copolymerize with trimesoyl chloride along with piperazine to incorporate high-free-volume polyester (PE) segments, but also retard the diffusion of piperazine toward the interface. This strategy simultaneously manipulates the diffusion kinetics of piperazine and the reaction kinetics of polyphenols, yielding ultrathin PEA membranes with well-defined surface charge and enhanced microporosity. The PEA membranes exhibit property sets that far exceed conventional PA membranes and commercial NF membrane benchmarks, including ultrahigh water permeance (33.7 L m –2 h –1 bar –1 ), orders of magnitude larger water/OMPs and mineral ions/OMPs selectivity, and exceptional chlorine resistance. The PP-RIP strategy can be extended to various plant polyphenol systems, providing an effective avenue for the precise synthesis of high-performance water purification membranes.