Wang Xiaohui, Li Yichen, Zhao Qian, Liu Guojin, Chai Liqin, Zhou Lan, Fan Qinguo, Shao Jianzhong
Engineering Research Centre for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Haining Green-Guard Textile Sci-Tech Company Ltd., Jiaxing 314408, China.
ACS Appl Mater Interfaces. 2021 Apr 28;13(16):19221-19229. doi: 10.1021/acsami.1c00176. Epub 2021 Apr 19.
Over the past years, photonic crystals (PCs) with a periodically ordered nanostructure have attracted great attention due to their potential as advanced optical materials for structural coloration of textiles. However, the weak structural stability of PCs on flexible textile substrates makes them vulnerable to strong external forces, hampering their large-scale application. In this work, a waterborne polyurethane (wPU) is chosen for enhancing the structural stability of PCs. The composite PCs (PCs/wPU) show both brilliant structural colors and significantly improved structural stability. The structural color produced by the encapsulated PCs is found to depend on the properties of encapsulating agents. The wPU with high surface tension solidifies mainly on the PC surface in the form of a transparent film, protecting the overall structure of PCs. Meanwhile, a small amount of wPU, infiltrating into the interior of PCs, provides strong adhesion and ensures stability among nanospheres. In turn, polydimethylsiloxane (PDMS) with low surface tension is easy to infiltrate into the interior of PCs, forming fully encapsulated PCs. This reduces the brightness of structural color produced by the final PCs/PDMS composite over the original PCs, due to the replacement of air by PDMS, and thus the decrease in the refractive index contrast of PCs. The supported curing strategy using the encapsulating agent with high surface tension is shown to not only improve the structural stability of PCs but also exert almost no influence on the optical properties of PCs, facilitating the practice application of structural coloration in the textile industry.
在过去几年中，具有周期性有序纳米结构的光子晶体（PCs）因其作为纺织品结构着色的先进光学材料的潜力而备受关注。然而，PCs在柔性纺织基材上的结构稳定性较弱，使其容易受到强大外力的影响，阻碍了它们的大规模应用。在这项工作中，选择了水性聚氨酯（wPU）来增强PCs的结构稳定性。复合PCs（PCs/wPU）既呈现出鲜艳的结构颜色，又具有显著提高的结构稳定性。发现封装PCs产生的结构颜色取决于封装剂的性质。具有高表面张力的wPU主要以透明薄膜的形式固化在PCs表面，保护PCs的整体结构。同时，少量的wPU渗透到PCs内部，提供强附着力并确保纳米球之间的稳定性。反过来，具有低表面张力的聚二甲基硅氧烷（PDMS）很容易渗透到PCs内部，形成完全封装的PCs。由于PDMS取代了空气，从而降低了PCs的折射率对比度，这使得最终的PCs/PDMS复合材料产生的结构颜色的亮度低于原始PCs。使用具有高表面张力的封装剂的支撑固化策略不仅提高了PCs的结构稳定性，而且对PCs的光学性能几乎没有影响，有利于结构着色在纺织工业中的实际应用。
