Polyimide Covalent-Organic Frameworks for Aqueous Actinide Sequestration: Combined Ab Initio and Molecular Dynamics
Hayden Brandt1, Robert Stanton1, Mason Cartier1
1Department of Physics, Clarkson University, Potsdam, New York 13699, United States.
The Journal of Physical Chemistry Letters
|December 11, 2025
Summary
This study computationally evaluates polyimide covalent-organic frameworks (PI-COFs) for capturing radioactive actinides like uranium and plutonium. PI-COF-3 shows high selectivity for plutonium, aiding nuclear waste management and resource recycling.
Area of Science:
- Materials Science
- Nuclear Chemistry
- Computational Chemistry
Background:
- Nuclear power expansion requires managing actinide waste, specifically plutonium and uranium.
- Selective capture and recovery of actinides are vital for environmental safety and advanced fuel cycles.
- Covalent-organic frameworks (COFs) offer tunable properties for efficient actinide sequestration.
Purpose of the Study:
- To computationally assess polyimide COFs (PI-COFs) for detecting and capturing uranyl (UO2^2+) and plutonyl (Pu^4+) ions.
- To investigate the adsorption energetics and diffusion dynamics of actinides within PI-COFs.
- To identify structural features of PI-COFs that enhance actinide sequestration.
Main Methods:
- Utilized a multiscale computational approach combining ab initio density functional theory (DFT) and molecular dynamics (MD) simulations.
- Characterized adsorption energies and diffusion dynamics of UO2^2+ and Pu^4+ in PI-COFs.
- Analyzed the impact of framework structure and functional groups on host-guest interactions.
Main Results:
- PI-COF-1 demonstrated the strongest adsorption for UO2^2+.
- PI-COF-3 exhibited the highest adsorption energy and selectivity for Pu^4+.
- Framework stacking and nitrogen-rich groups were found to enhance actinide binding and ion transport.
Conclusions:
- Specific PI-COF designs can effectively sequester actinides from aqueous solutions.
- Computational insights guide the optimization of PI-COFs for actinide capture and recycling.
- This work provides a foundation for experimental validation and development of advanced nuclear materials.
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