Nanotech Now

COF Scaffold Membrane with Gate‑lane Nanostructure for Efficient Li+/Mg2+ Separation

Researchers from Tianjin University, NUS and Sichuan University unveiled a covalent‑organic‑framework (COF) scaffold membrane featuring a gate‑lane nanostructure that simultaneously achieves record‑high Li⁺/Mg²⁺ selectivity (231.9) and high Li⁺ flux (11.5 L m⁻² h⁻¹ bar⁻¹). The membrane’s positively charged gating layer rejects Mg²⁺ while an underlying COF/PEI layer creates distinct Li⁺ and Cl⁻ transport lanes, delivering >99% Mg²⁺ rejection over seven days under harsh brine conditions. Its thin 135 nm profile and roll‑to‑roll compatible fabrication promise scalable deployment for battery‑grade lithium recovery. The study positions the gate‑lane design as a blueprint for next‑generation ion‑separation technologies.