Interaction-based ion selectivity exhibited by self-assembled, cross-linked zwitterionic copolymer membranes

Journal Article · 07 September 2021 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.2022198118 · OSTI ID:1819227

Lounder, Samuel J.  ^[1]; Asatekin, Ayse ^[1]

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1. Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155

Significance The separation of ions is challenging yet crucial for providing access to safe water resources as well as recovering valuable ions from water and wastewater. Yet, membranes rarely exhibit selectivity between ions of similar charge and size. We demonstrate that membranes, prepared by a fully scalable method that uses self-assembling zwitterionic copolymers, exhibit exceptional selectivity between salt anions of similar size and charge. We show that this unusual capability is derived from selective zwitterion–ion interactions occurring within the nanochannels, similarly to biological ion channels. We further demonstrate these membranes exhibit Cl ⁻ /F ⁻ permselectivity more than twice the values reported in previous studies, with applications in treating groundwater streams to prevent fluorosis and in wastewater treatment.

• Sponsoring Organization: USDOE
• OSTI ID: 1819227
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 37 Vol. 118; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English