Kevlar Aerogel‐Confined Functional Liquid‐Based Composite Membrane Enables Dynamic Uranium Capture

Solid–liquid composite materials that confine a functional liquid within a porous solid have appeared in a wealth of emerging applications. However, creating dynamic liquid interfaces for efficient ion capture while stably retaining functional liquid in porous confinements is challenging. Here, an aerogel‐confined liquid‐based composite membrane (ALCM) for dynamic and highly efficient uranium capture is reported. As a proof of concept, Kevlar aerogel membrane is selected as the nanoporous solid, and calix[6]arene/tributyl phosphate (C6/TBP) is used as the guest liquid. The obtained ALCMs possess high stability, optimum adhesion between solid‐liquid interface, and high selectivity for uranyl ions (250–6510 times over other competing ions). Different dynamic interface regulating approaches are explored for ALCMs, and uranium extraction efficiency under alternating pressures can be up to 258.48 mg g−1 h−1, outperforming many reported uranium capture materials. This strategy can be applicable to develop a rich family of solid‐liquid composite materials and may spearhead a new paradigm for uranium capture from sustainable seawater resources. Aerogel‐confined liquid‐based composite membranes (ALCMs) are constructed for dynamic ion capture, enabling highly efficient uranium extraction from seawater. This strategy could shed light on developing a wealth of solid–liquid composite materials and may spearhead a new paradigm for uranium capture or other valuable metal exploration.