Title: Dynamic Structural Colors in Helical Superstructures from Supramolecules to Polymers

Author: Bo Ji, Lang Qin*, Yanlei Yu*

Journal: Chinese J. Polym. Sci., 2025, 43(3), 406−428

Abstract:

Cholesteric liquid crystals (CLCs) exhibit unique helical superstructures that selectively reflect circularly polarized light, enabling them to dynamically respond to environmental changes with tunable structural colors. This dynamic color-changing capability is crucial for applications that require adaptable optical properties, positioning CLCs as key materials in advanced photonic technologies. This review focuses on the mechanisms of dynamic color tuning in CLCs across various forms, including small molecules, cholesteric liquid crystal elastomers (CLCEs), and cholesteric liquid crystal networks (CLCNs), and emphasizes the distinct responsive coloration each structure provides. Key developments in photochromic mechanisms based on azobenzene, dithienylethene, and molecular motor switches, are discussed for their roles in enhancing the stability and tuning range of CLCs. We examine the color-changing behaviors of CLCEs under mechanical stimuli and CLCNs under swelling, highlighting the advantages of each form. Following this, applications of dynamic color-tuning CLCs in information encryption, adaptive camouflage, and smart sensing technologies are explored. The review concludes with an outlook on current challenges and future directions in CLC research, particularly in biomimetic systems and dynamic photonic devices, aiming to broaden their functional applications and impact.

论文链接：https://link.springer.com/article/10.1007/s10118-025-3279-9#citeas

PDF下载：Dynamic Structural Colors in Helical Superstructures from Supramolecules to Polymers.pdf

文章概述：

本文章系统综述了CLCs的动态结构色调控机制及最新研究进展。该综述聚焦于光、力、溶剂等多种外界刺激下的颜色调控策略，深入探讨了分子设计、材料加工和响应机制等关键因素对结构色动态调控的影响，重点介绍了基于不同材料体系的三种典型的动态变色机制：

1. 光致变色：远程光操控的超分子体系基于光响应手性掺杂剂（如偶氮苯、二芳基乙烯、分子马达等）的超分子体系，CLCs通过光照远程调控螺旋结构，实现从紫外到近红外的全光谱动态变色。不仅极大扩展了可调的反射波长范围，还为光学图案化、信息加密及防伪技术提供了革命性解决方案。光响应能力的精确性和快速性，使得这一变色机制在智能光学设备中展现出无可比拟的优势。

2. 力致变色：机械力响应的胆甾相液晶弹性体（CLCEs）低交联度的CLCEs通过机械力驱动螺旋结构变形，实现反射波长的快速蓝移及可逆恢复。不同于传统材料的静态特性，CLCEs可以在拉伸和变形中实时响应外力的变化来改变颜色，可通过3D打印技术制备成复杂形状的纤维或薄膜。将其软弹性与动态共价键（如硼酸酯键、二硫键）的结合，赋予材料自修复能力和网络重编程特性，为可穿戴传感和软体机器人提供了兼具力学强度与光学活性的功能材料。

3. 溶胀变色：环境响应的胆甾相液晶网络（CLCNs）CLCNs高交联度的网络结构不仅固定了螺旋超结构，还使得材料能够通过溶剂或湿度诱导的网络溶胀，展现出大范围、高精度的颜色调控能力，从而实现颜色的“智能切换”。CLCNs对环境湿度的超灵敏响应，为智能传感和环境监测提供了创新的解决方案。