State Key Laboratory of Pulp and Paper Engineering, Plant Fiber Research Center, School of Light Industry and Engineering, South China University of Technology, Guangzhou, CN510640, China.
Small. 2021 Jul;17(30):e2007306. doi: 10.1002/smll.202007306. Epub 2021 May 28.
As a nanoscale renewable resource derived from lignocellulosic materials, cellulose nanocrystals (CNCs) have the features of high purity, high crystallinity, high aspect ratio, high Young's modulus, and large specific surface area. The most interesting trait is that they can form the entire films with bright structural colors through the evaporation-induced self-assembly (EISA) process under certain conditions. Structural color originates from micro-nano structure of CNCs matrixes via the interaction of nanoparticles with light, rather than the absorption and reflection of light from the pigment. CNCs are the new generation of photonic liquid crystal materials of choice due to their simple and convenient preparation processes, environmentally friendly fabrication approaches, and intrinsic chiral nematic structure. Therefore, understanding the forming mechanism of CNCs in nanoarchitectonics is crucial to multiple fields of physics, chemistry, materials science, and engineering application. Herein, a timely summary of the chiral photonic liquid crystal films derived from CNCs is systematically presented. The relationship of CNC, structural color, chiral nematic structure, film performance, and applications of chiral photonic liquid crystal films is discussed. The review article also summarizes the most recent achievements in the field of CNCs-based photonic functional materials along with the faced challenges.
作为一种源自木质纤维素材料的纳米可再生资源，纤维素纳米晶体（CNC）具有高纯度、高结晶度、高纵横比、高杨氏模量和大比表面积等特点。最有趣的特点是，它们可以通过一定条件下的蒸发诱导自组装（EISA）过程形成具有明亮结构色的整体薄膜。结构色源于 CNCs 基质的微纳结构，通过纳米颗粒与光的相互作用产生，而不是来自颜料的光吸收和反射。由于其简单方便的制备工艺、环保的制造方法和内在的手性向列结构，CNC 是新一代光子液晶材料的首选。因此，理解纳米结构中 CNC 的形成机制对于物理、化学、材料科学和工程应用的多个领域至关重要。本文系统地总结了由 CNC 衍生的手性光子液晶薄膜。讨论了 CNC、结构色、手性向列结构、薄膜性能和手性光子液晶薄膜的应用之间的关系。综述文章还总结了基于 CNC 的光子功能材料领域的最新成果以及面临的挑战。
