Zheng Yuewei, Chen Jinqing, Mo Wanqi, Hong Wei
Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, P. R. China.
Adv Sci (Weinh). 2025 Aug;12(32):e06507. doi: 10.1002/advs.202506507. Epub 2025 Jun 4.
Counterfeiting remains a pervasive global challenge, persistently undermining legitimate enterprises. Despite advancements, current anti-counterfeiting materials and technologies fall short in addressing the escalating sophistication of counterfeit activities. A significant hurdle in this domain is the difficulty in achieving multi-mode dynamic anti-counterfeiting materials. Herein, thermo-responsive tri-state photonic crystals is presented that enable thermochromism of structural color, fluorescence (FL), and organic afterglow. The fabrication of this system integrates the incorporation of organic phosphors into polymeric colloids via solid-phase extraction and embeds thermochromic microcapsules into colloidal crystals to regulate incoherent scattering and far-field light absorption. In typical triplet-to-singlet Förster resonance energy transfer (TS-FRET) for afterglow color tuning, higher energy transfer efficiency reduces the afterglow lifetime. In contrast, the far-field light absorption-based energy transfer in this photonic crystal system avoids this trade-off, thereby preserving the long-lived triplet emission. The resultant photonic crystals exhibit three thermochromic optical states including FL, phosphorescent, and structural coloration. This general strategy, leveraging tunable thermochromic temperatures and diverse organic phosphors, enables the creation of multi-responsive anti-counterfeiting patterns. It paves the way for dynamic, high-capacity, and multimodal information storage.
假冒伪劣仍然是一个普遍存在的全球性挑战，持续损害着合法企业。尽管取得了进展，但当前的防伪材料和技术在应对日益复杂的假冒活动方面仍存在不足。该领域的一个重大障碍是难以实现多模式动态防伪材料。在此，我们展示了热响应三态光子晶体，它能够实现结构色、荧光（FL）和有机余辉的热致变色。该系统的制备通过固相萃取将有机磷光体掺入聚合物胶体，并将热致变色微胶囊嵌入胶体晶体中，以调节非相干散射和远场光吸收。在用于余辉颜色调谐的典型三线态到单线态福斯特共振能量转移（TS-FRET）中，较高的能量转移效率会缩短余辉寿命。相比之下，该光子晶体系统中基于远场光吸收的能量转移避免了这种权衡，从而保留了长寿命的三线态发射。所得的光子晶体呈现出包括FL、磷光和结构着色在内的三种热致变色光学状态。这种利用可调热致变色温度和多种有机磷光体的通用策略，能够创建多响应防伪图案。它为动态、高容量和多模式信息存储铺平了道路。
