Fabrication of Large‐area Multi‐stimulus Responsive Thin Films via Interfacially Confined Irreversible Katritzky Reaction

Abstract Fabrication of large‐area thin films through irreversible reactions remains a formidable task. This study reports a breakthrough strategy for in situ synthesis of large‐area, free‐standing, robust and multi‐stimulus responsive thin films through a catalyst‐free and irreversible Katritzky reaction at a liquid–liquid interface. The as resulted films are featured with adjustable thickness of 1–3 μm and an area up to 50 cm 2 . The thin films exhibit fast photo‐mechanical motions (a response time of ca 0.1 s), vapor‐mechanical motions, as well as photo‐chromic and solvato‐chromic behaviors. It was revealed that the reason behind the observable motions is proton transfer from the imine groups to the carbonyl structures within the film induced by photo‐ and/or dimethyl sulfoxide‐stimulus. In addition, the films can harvest anionic radicals and the radicals as captured can be efficiently degraded under UV light illumination. This study provides a new strategy for fabricating smart thin films via interfacially confined irreversible Katritzky reaction.