Reversible shape memory two-dimensional covalent organic frameworks
Mingchao Shao1,2, Jinyang Chen1,3, Wenqiang Gao1,4
1Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, PR China.
Nature Communications
|October 10, 2025
Summary
Shape memory two-dimensional covalent organic frameworks exhibit reversible stacking phases and tunable pore sizes. This breakthrough enables dynamic control over permeability and intelligent responses for advanced applications.
Area of Science:
- Materials Science
- Nanotechnology
- Organic Chemistry
Background:
- Two-dimensional covalent organic frameworks (2DCOFs) possess unique properties like nanochannels and tunable pore sizes.
- Reversible stacking phases in 2DCOFs are crucial for applications in nanoelectronics, nanoreactors, and gas separation.
- Achieving controllable reversible stacking, beyond the stable slipped AA-phase, remains a significant challenge.
Purpose of the Study:
- To engineer 2DCOFs with shape memory properties and reversible interlayer stacking sequences.
- To explore stimuli-responsive mechanisms for controlling pore size and environment in 2DCOFs.
- To demonstrate the potential of these materials in dynamically tunable permeability and intelligent response systems.
Main Methods:
- Synthesis of 2DCOFs designed for reversible stacking.
- Induction of different stacking phases (AA and inclined) using controlled conditions like 'hot ice' formation.
- Adsorption of molecules (e.g., Tetrahydrofuran) within confined nanochannels to influence interlayer interactions.
Main Results:
- Successfully realized shape memory 2DCOFs with switchable interlayer stacking.
- Demonstrated that 'hot ice' induces AA stacking, while adsorbed Tetrahydrofuran induces inclined stacking.
- Showcased reversible changes in pore size and environment within the 2DCOF nanochannels.
Conclusions:
- The developed shape memory 2DCOFs offer a novel platform for dynamic pore size and environment control.
- These materials exhibit tunable permeability, paving the way for intelligent responsive systems.
- The findings present significant potential for future advancements in nanoelectronics, nanoreactors, and separation technologies.
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