College of Materials Science and Engineering, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China.
Bioproducts Institute, Department of Chemical and Biological Engineering, Department of Chemistry and Department of Wood Science, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
Small. 2021 Dec;17(50):e2103936. doi: 10.1002/smll.202103936. Epub 2021 Oct 17.
The need for a precise regulation of the properties of chiral nematic structures in response to external stimuli is addressed. Self-assembled iridescent coatings are produced under the effect of electrostatic interactions between cellulose nanocrystals and poly(acrylic acid), endowing a high anisotropic dissymmetry (>0.3) and sensitivity to environmental humidity (13.1 nm/1% at 68-75% relative humidity, RH). The phenomena associated with shifts in selective light reflection (green to orange) and polarization, facilitate tunable transmitted colors (blue to orange) at given rotation angles (RA). Such properties are conveniently integrated into a "RH-RA-color" ternary code that is introduced as an anticounterfeiting technology, taking advantage of multicolor patterns that conveniently track with changes in RH and RA. The proposed charge-driven assembly opens new opportunities for chiral nematic materials that enable precise optical sensing and information encryption.
需要精确调节手性向列结构的性质以响应外部刺激。在纤维素纳米晶体和聚丙烯酸之间的静电相互作用的影响下，产生自组装的彩虹色涂层，赋予高各向异性的不对称性（>0.3）和对环境湿度的敏感性（在 68-75%相对湿度下为 13.1nm/1%）。与选择性光反射（绿色到橙色）和偏振变化相关的现象，在给定的旋转角度（RA）下，使可调谐的透射颜色（从蓝色到橙色）成为可能。这些特性方便地集成到“RH-RA-颜色”三元码中，作为一种防伪技术，利用方便地跟踪 RH 和 RA 变化的多色图案。所提出的电荷驱动组装为手性向列材料开辟了新的机会，使精确的光学传感和信息加密成为可能。
