Ryabchun Alexander, Florida Yunita, Li Quan, Plamont Rémi, Katsonis Nathalie, Aprahamian Ivan
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 3, Groningen, 9747AG, The Netherlands.
Department of Chemistry, 6128 Burke Laboratory, Dartmouth College, Hanover, New Hampshire, 03755, USA.
Angew Chem Int Ed Engl. 2025 Jul 28;64(31):e202507358. doi: 10.1002/anie.202507358. Epub 2025 Jun 5.
Developing responsive coatings and materials requires discovering a breadth of mechanisms by which external stimuli can be converted into useful signals. Here, we demonstrate an approach driven by supramolecular mechanochemistry, where mechanical input-molecular shape change-is translated into structural color variation. By embedding bistable, negatively photochromic hydrazone photoswitches into cholesteric polymer networks, we achieve a reversible, stable color shift through molecular-scale pulling and pushing of the photonic scaffold. Unlike azobenzene-based systems, which typically disrupt liquid crystal order, this approach modifies the pitch of a cross-linked cholesteric helix without disrupting the organisation of the material. The long-lived stability of both hydrazone isomers ensures durable optical switching. This effect provides a new strategy for designing mechanoresponsive photonic coatings and tunable optical materials.
开发响应性涂层和材料需要发现多种机制，通过这些机制外部刺激可以转化为有用信号。在此，我们展示了一种由超分子机械化学驱动的方法，其中机械输入——分子形状变化——被转化为结构颜色变化。通过将双稳态、负性光致变色腙光开关嵌入胆甾型聚合物网络中，我们通过对光子支架进行分子尺度的拉伸和挤压实现了可逆、稳定的颜色变化。与通常会破坏液晶有序性的基于偶氮苯的系统不同，这种方法改变了交联胆甾型螺旋的螺距，而不会破坏材料的组织结构。两种腙异构体的长寿命稳定性确保了持久的光学开关性能。这种效应为设计机械响应性光子涂层和可调谐光学材料提供了一种新策略。
