School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China.
Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, P. R. China.
Small Methods. 2022 May;6(5):e2200269. doi: 10.1002/smtd.202200269. Epub 2022 Apr 10.
Design and fabrication of freestanding chiro-photonic crystal film with the ability to change color over the whole visible light spectrum is appealing for anticounterfeiting technology and smart labels. Utilizing a newly synthesized light-responsive molecular motor functionalized with cholesterol (chol-MM) on the rotor, novel light-controlled photonic crystal is prepared by doping the novel chol-MM into liquid crystals (LCs). Thanks to the liquid crystalline cholesterol substituent, the chol-MM can be triggered by visible light (420 nm). At the same time, the miscibility of chol-MM in LC matrix is significantly enhanced. Integrating the chol-MM with thermochromic hydrogen-bonded LC matrix, thermal and light dual-responsive cholesteric LC (CLC) material is prepared, in which the nanoscale helical pitch is tunable by photo-induced molecular motions of chol-MM. More importantly, utilizing UV-initiated polymerization of the visible light-modulated CLC material, structural colored photonic crystal films with arbitrary colorful patterns are fabricated. Such freestanding helical nanostructured labels have potential in the application of encrypted communication and anticounterfeiting.
具有在整个可见光范围内改变颜色能力的自由-standing 手性光子晶体膜的设计与制造，对于防伪技术和智能标签来说非常有吸引力。利用在转子上功能化了新型光响应分子马达的胆固醇（chol-MM），通过将新型 chol-MM 掺杂到液晶（LCs）中制备出新型光控光子晶体。由于液晶胆固醇取代基的存在，chol-MM 可以被可见光（420nm）触发。同时，chol-MM 在 LC 基体中的混溶性显著增强。将 chol-MM 与热致变色氢键 LC 基体相结合，制备出热光双响应胆甾相 LC（CLC）材料，其中纳米级螺旋间距可以通过 chol-MM 的光诱导分子运动来调节。更重要的是，利用可见光调控的 CLC 材料的紫外光引发聚合，可以制备出具有任意彩色图案的结构色光子晶体膜。这种自由-standing 螺旋纳米结构标签在加密通信和防伪方面具有潜在的应用价值。
