Robust uranium-capturing membranes enabled by synergistic sulfonation and thiol-ene click crosslinking

Area of Science:

• Materials Science
• Environmental Chemistry
• Nuclear Engineering

Background:

• Conventional amidoxime adsorbents for uranium extraction face challenges balancing adsorption capacity and mechanical stability.
• Nuclear wastewater treatment requires efficient and robust materials for uranium removal.

Purpose of the Study:

• To engineer a robust, self-supporting adsorptive membrane for efficient uranium extraction from nuclear wastewater.
• To overcome the trade-off between adsorption capacity and mechanical stability in uranium adsorbents.

Main Methods:

• Synergistic sulfonation and UV-assisted thiol-ene click crosslinking of sulfonated poly(arylene ether nitrile).
• Incorporation of photo-crosslinkable allyl groups to form a 3D network.
• Density functional theory (DFT) calculations to elucidate the uranium adsorption mechanism.

Main Results:

• The engineered membrane exhibits a high uranium adsorption capacity (488 mg g⁻¹) and reaches equilibrium within 24 hours.
• The membrane demonstrates excellent mechanical robustness with a tensile strength of ~2.3 MPa and retains 87% capacity after seven cycles.
• DFT calculations confirm amidoxime-dominated uranyl chelation, assisted by sulfonic groups.

Conclusions:

• The developed membrane offers a promising structural design for robust uranium adsorptive materials in nuclear wastewater treatment.
• The synergistic approach enhances both adsorption efficiency and material stability, addressing critical limitations of existing technologies.