Solvation‐amination‐synergy that neutralizes interfacially polymerized membranes for ultrahigh selective nanofiltration

Molecular desalination is broadly used in chemical, food, and textile industries, which needs efficient and anti‐fouling separation technologies to reach this goal. Interfacial polymerization is one of the most promising routes to construct ultrahigh selective nanofiltration membranes. However, the irreversible hydrolysis of residual acyl chlorides makes Donnan charges of nascent films distribute unevenly which hinders fine molecular desalination and anti‐fouling. Here, we propose a pioneering solvation‐amination‐synergy strategy to synchronously inhibit the hydrolysis of residual acyl chlorides and promote their amination. The electroneutral nanofiltration membrane with high water permeance (13.2 L m−2 h−1 bar−1) is quantitatively fabricated that has superb anti‐fouling abilities and minimizes Donnan impacts on competitive ion penetrations, so it transmits Na2SO4 and NaCl while fully obstructs cationic or anionic dyes (< 500 Da). The ultrahigh molecule to ion selectivities outperform state‐of‐art nanofiltration membranes, which may provide a paradigm shift for scalable membrane fabrication for various industrial product desalination.