Abstract
Biomimetic ion channels demonstrate potential for nanoscale molecular separations by leveraging their unique confined recognition capabilities. Metal-organic framework (MOF)-based mixed matrix membranes (MMMs) offer a promising platform that integrates the ångström-scale pores of MOFs with polymer processability. However, slow MOF nucleation kinetics and weak interfacial interactions impede precise channel formation. Here, we present a confined molecular encapsulation (CME) strategy that synchronously regulates MOF nucleation kinetics and interfacial interactions, transforming precursors into flexible gel-network metal-organic gels (MOGs) via supramolecular assembly. Molecular dynamics simulations and in-situ optical detection show that stronger MOG-polymer interactions and confined diffusion govern enhanced interfacial compatibility and uniform dispersion. Optimized MMMs deliver a F⁻/Cl⁻ separation ratio of 32.0 with ionic current rectification. COMSOL simulations demonstrate that synergistic coupling of aligned MOF arrays and uniform surface charge enables efficient ion differentiation. This CME strategy establishes a versatile nanoscale platform for fabricating high-performance monovalent ion-selective membranes and nanofluidic devices.
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Acknowledgements
The authors gratefully acknowledge the research funding provided by National Key Research and Development Program (2023YFE0100900, S.P.S.), the National Natural Science Foundation of China (22208150, M.L.L.), Jiangsu Science and Technology Department (BK20232010, S.P.S.), and Jiangsu Future Membrane Technology Innovation Center (BM2021804, S.P.S. and M.L.L.).
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Q.C. and L.M.L. developed the research concept, carried out the experiments, analyzed the data, and prepared the manuscript. S.J. and Y.W.J. conducted supplementary experimental and simulation studies. Y.T.Z. provided guidance on testing methods. W.X.L. and W.H.X. performed the theoretical analysis. S.P.S. initiated the research, developed the research concept, managed the project, and supervised the work. All authors contributed to discussions and revised the manuscript.
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Q. Chen, M.-L. Liu, S.-P. Sun, and Y.-T. Zhang are inventors on a Chinese patent application related to this work filed by Nanjing Tech University (application no. 202510678790.7). All other authors declare no competing interests.
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Chen, Q., Liu, ML., Jiang, S. et al. In-situ growth of biomimetic ion-selective membranes via confined molecular encapsulation for superior fluoride/chloride separation. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71107-6
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DOI: https://doi.org/10.1038/s41467-026-71107-6
