Gating Gas Permeability Through Dynamic Cracking of Liquid Crystal Polymer Membranes.

Intelligent membranes promise transformative advances in real-time control of substance permeation, surpassing current technologies through their intrinsic adaptability to environmental stimuli. In this work, a material-regulated approach to dynamically control substance permeation, such as gas, using hybrid bilayer membranes composed of gold-coated liquid crystal oligomer networks (Au-LCONs), is established. Thermally driven LCON actuation induces a stress mismatch at the LCON-Au interface that cracks the Au layer, effectively opening "gates" in the impermeable Au to allow gas transport through the membrane; this reversible effect can be precisely controlled with temperature, facilitating the use of this system for triggering gas-mediated chemical reactions on demand. Furthermore, switchable gas transport can be localized by the patterned Au coating on LCONs, restricting gas flow and chemical reactions to designated areas. This work paves the way for advancing intelligent materials for applications with precise and switchable substance permeability requirements, such as environmental monitoring, drug delivery, preservation systems, and filtration technologies.