Zhu Keming, Zhou Xing, Wang Dong, Li Dexiang, Lei Wanqing, Fang Changqing, Hu Jingbo, Luo Rubai
School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an 710048, China.
Faculty of Printing, Packaging Engineering and Digital Media Technology, Xi'an University of Technology, Xi'an 710048, China.
Polymers (Basel). 2024 Sep 30;16(19):2774. doi: 10.3390/polym16192774.
Cellulose nanocrystals (CNCs) are a green resource which can produce photonic crystal films with structural colors in evaporation-induced self-assembly; CNC photonic crystal films present unique structural colors that cannot be matched by other colored materials. Recently, the mechanisms of CNC photonic crystal films with a unique liquid crystal structure were investigated to obtain homogenous, stable, and even flexible films at a large scale. To clarify the mechanism of colorful CNC photonic crystal films, we briefly summarize the recent advances from the correlations among the preparation methods, microstructures, and color properties. We first discuss the preparation process of CNCs, aiming to realize the green application of resources. Then, the behavior of CNCs in the formation of liquid crystal phases is studied, considering the influence of the CNCs' size and shape, surface properties, and the types and concentrations of solvents. Finally, the film formation process of CNCs and the control of structural colors during the film formation are summarized, as well as the mechanisms of CNC photonic crystal films with full color. In summary, considering the above factors, obtaining reliable commercial CNC photonic crystal films requires a comprehensive consideration of the subsequent preparation processes starting from the preparation of CNCs.
纤维素纳米晶体（CNCs）是一种绿色资源，可在蒸发诱导自组装过程中制备具有结构色的光子晶体薄膜；CNC光子晶体薄膜呈现出独特的结构色，这是其他有色材料无法比拟的。最近，对具有独特液晶结构的CNC光子晶体薄膜的机制进行了研究，以大规模获得均匀、稳定甚至柔性的薄膜。为阐明彩色CNC光子晶体薄膜的机制，我们简要总结了制备方法、微观结构和颜色特性之间相关性的最新进展。我们首先讨论CNCs的制备过程，旨在实现资源的绿色应用。然后，研究了CNCs在液晶相形成过程中的行为，考虑了CNCs的尺寸和形状、表面性质以及溶剂的类型和浓度的影响。最后，总结了CNCs的成膜过程以及成膜过程中结构色的控制，以及全色CNC光子晶体薄膜的机制。总之，考虑到上述因素，要获得可靠的商用CNC光子晶体薄膜，需要从CNCs的制备开始，对后续制备过程进行全面考虑。
