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Updated: Feb 22, 2026
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Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
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Reversible Bond Dynamics Enable Crystallinity-Healed COF Membranes for Selective Ion Transport
Wenming Zhao1, Jindi Yang1,2, Zhuyuan Wang1,2
1UQ Dow Centre For Sustainable Engineering Innovation, School of Chemical Engineering, The University of Queensland, St Lucia, Australia.
Small (Weinheim an Der Bergstrasse, Germany)
|February 20, 2026
Summary
Researchers developed a "make-then-heal" method for creating robust covalent organic framework (COF) membranes. This technique improves crystallinity, significantly boosting proton conductivity and ion selectivity for advanced separation applications.
Area of Science:
- Materials Science
- Nanotechnology
- Chemical Engineering
Background:
- Covalent organic frameworks (COFs) possess ordered channels ideal for selective ion transport membranes.
- Fabricating robust COF membranes while maintaining high crystallinity is a significant challenge.
- Existing methods often struggle to balance membrane formation with structural integrity.
Purpose of the Study:
- To develop a novel strategy for fabricating high-performance COF membranes.
- To address the challenge of preserving COF crystallinity during membrane formation.
- To enhance ion transport properties and selectivity in COF-based membranes.
Main Methods:
- Decoupling COF crystallization from membrane formation using a "make-then-heal" approach.
- Fabricating initial COF membranes via interfacial polymerization.
- Employing acid-catalyzed hydrothermal conditions for framework self-correction and healing via bond exchange.
Main Results:
- Achieved a 25-fold enhancement in the (100) X-ray diffraction peak intensity, indicating improved crystallinity.
- Observed a 375% increase in proton conductivity in the healed COF membranes.
- Demonstrated enhanced monovalent cation-cation selectivity, crucial for separation processes.
Conclusions:
- The "make-then-heal" strategy effectively produces structurally precise, crystallinity-healed COF membranes.
- Dynamic covalent chemistry is key to achieving self-correction and improved membrane properties.
- This approach offers a promising pathway for advanced COF membrane applications in selective ion transport.
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