Wang Xiaojie, Xu Dan, Jaquet Bea, Yang Yang, Wang Jiaxiu, Huang Heqin, Chen Ye, Gerhard Christoph, Zhang Kai
Wood Technology and Wood Chemistry, Department of Wood Technology and Wood-based Composites, Georg-August-University of Göttingen, Büsgenweg 4, D-37077 Göttingen, Germany.
Faculty of Engineering and Health, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen, Germany.
ACS Nano. 2020 Dec 22;14(12):16832-16839. doi: 10.1021/acsnano.0c05599. Epub 2020 Dec 8.
One-dimensional nanomaterials including cellulose nanocrystals (CNCs) and gold nanorods (GNRs) are widely used in optical materials due to their respective inherent features: birefringence with accompanying light retardation and surface plasmon resonance (SPR). Herein, we successfully combine these properties of both nanorods to generate synergistic and readily tunable structural colors in hybrid composite polymer films. CNCs and GNRs are embedded either in the same or in separate films after unidirectional alignment in dynamic hydrogels. By synergistically leveraging CNCs and GNRs with diverse amounts in hybrid films or stacked separate films, wide-ranging structural colors are obtained, far beyond those from films solely with aligned CNCs or GNRs. Higher GNR contents enhance light absorption at 520 nm with promoted magenta colors, while more CNCs affect the overall phase retardation with light absorption between 400 and 700 nm between crossed polarizers. Moreover, adjusting the angles between films solely with CNCs or GNRs a stacking/rotating technique successively manipulates colors with flexible film combinations. By rotating the films with aligned GNRs (0-180°), light absorption can traverse from ∼500 to 650 nm. Thus, tuning the adjustable synergism of birefringence of CNCs and SPR of GNRs provides great potential for structural colors, which enlightens inspirations for designing functional optical materials.
包括纤维素纳米晶体（CNCs）和金纳米棒（GNRs）在内的一维纳米材料，因其各自的固有特性，即伴随光程差的双折射和表面等离子体共振（SPR），而被广泛应用于光学材料中。在此，我们成功地将这两种纳米棒的特性结合起来，在混合复合聚合物薄膜中产生协同且易于调节的结构色。在动态水凝胶中进行单向排列后，CNCs和GNRs被嵌入到同一薄膜或单独的薄膜中。通过在混合薄膜或堆叠的单独薄膜中协同利用不同数量的CNCs和GNRs，可获得范围广泛的结构色，远远超过仅含有排列的CNCs或GNRs的薄膜所产生的结构色。较高的GNR含量可增强在520 nm处的光吸收，并呈现出更明显的品红色，而更多的CNCs则会影响整体相位延迟，并在交叉偏振器之间产生400至700 nm之间的光吸收。此外，通过一种堆叠/旋转技术，调整仅含有CNCs或GNRs的薄膜之间的角度，可通过灵活的薄膜组合连续操纵颜色。通过旋转排列有GNRs的薄膜（0 - 180°），光吸收可从约500 nm到650 nm。因此，调节CNCs双折射和GNRs SPR之间的可调协同作用为结构色提供了巨大潜力，这为设计功能性光学材料带来了启示。
