Precision ion separation via self-assembled channels

by S. Hong, M. di Vincenzo, A. Tiraferri, E. Bertozzi, R. Górecki, B. Davaasuren, X. Li, S. P. Nunes
Journal Article Year: 2024 DOI:

Extra Information

Nature Communications, 15, 3160


Selective nanofiltration membranes with accurate molecular sieving offer a solution to recover rare metals and other valuable elements from brines. However, the development of membranes with precise sub-nanometer pores is challenging. Here, we report a scalable approach for membrane fabrication in which functionalized macrocycles are seamlessly oriented via supramolecular interactions during the interfacial polycondensation on a polyacrylonitrile support layer. The rational incorporation of macrocycles enables the formation of nanofilms with self-assembled channels holding precise molecular sieving capabilities and a threshold of 6.6 ångström, which corresponds to the macrocycle cavity size. The resulting membranes provide a 100-fold increase in selectivity for Li+/Mg2+ separation, outperforming commercially available and state-of-the-art nanocomposite membranes for lithium recovery. Their performance is further assessed in high-recovery tests under realistic nanofiltration conditions using simulated brines or concentrated seawater with various Li+ levels and demonstrates their remarkable potential in ion separation and Li+ recovery applications.


Ion separation Lithium recovery Macrocycles self-assembly Thin film composite