Tuneable ion selectivity in vermiculite membranes intercalated with unexchangeable ions
Membranes selective to ions of the same charge are increasingly sought for water waste processing and valuable element recovery. However, while narrow channels are known to be essential, other membrane parameters remain difficult to identify and control. Here we show that Zr⁴⁺, Sn⁴⁺, Ir⁴⁺, and La³⁺ ions intercalated into vermiculite laminate membranes become effectively unexchangeable, creating stable channels, one to two water layers wide, that exhibit robust and tuneable ion selectivity. Ion permeability in these membranes spans five orders of magnitude, following a trend dictated by the ions' Gibbs free energy of hydration. Unexpectedly, different intercalated ions lead to two distinct monovalent ion selectivity sequences, despite producing channels of identical width. The selectivity instead correlates with the membranes' stiffness and the entropy of hydration of the intercalated ions. These results introduce an ion selectivity mechanism driven by entropic and mechanical effects, beyond classical size and charge exclusion.
Authors
- Min Cao
- Eli Hoenig
- Liang‐Yin Chu (ORCID: https://orcid.org/0000-0002-2676-6325)
- Guowei Yang (ORCID: https://orcid.org/0000-0003-2141-6630)
- M. Lozada-Hidalgo (ORCID: https://orcid.org/0000-0003-3216-7537)
- Jianhao Qian (ORCID: https://orcid.org/0000-0003-0508-7494)
- François Maria Peeters (ORCID: https://orcid.org/0000-0003-3507-8951)
- Yichao Zou (ORCID: https://orcid.org/0000-0002-4171-7185)
- Zhuang Liu (ORCID: https://orcid.org/0000-0001-6898-5908)
- Fengchao Wang (ORCID: https://orcid.org/0000-0002-5954-3881)
- Yumei Tan
Institutions
- University of Science and Technology of China (CN)
- University of Antwerp (BE)
- Sun Yat-sen University (CN)
- Sichuan University (CN)
- Universidade Federal do Ceará (BR)
- University of Manchester (GB)
- Ingenierie des Materiaux polymeres (FR)
- Province of Antwerp (BE)
- Rice University (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-12-02
- DOI
- https://doi.org/10.1038/s41467-025-66545-7
- Primary Topic
- Membrane-based Ion Separation Techniques
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- UK Research and Innovation
- Royal Society
- National Natural Science Foundation of China
- Natural Science Foundation of Guangdong Province
- Sichuan University
- Fundamental Research Funds for the Central Universities