Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada.
FPInnovations, 2665 East Mall, Vancouver, BC, V6T 1Z4, Canada.
Nat Commun. 2019 Jan 31;10(1):510. doi: 10.1038/s41467-019-08351-6.
Cellulose nanocrystals (CNCs) derived from biomass spontaneously organize into a helical arrangement, termed a chiral nematic structure. This structure mimics the organization of chitin found in the exoskeletons of arthropods, where it contributes to their remarkable mechanical strength. Here, we demonstrate a photonic sensory mechanism based on the reversible unwinding of chiral nematic CNCs embedded in an elastomer, leading the materials to display stimuli-responsive stretchable optics. Vivid interference colors appear as the film is stretched and disappear when the elastomer returns to its original shape. This reversible optical effect is caused by a mechanically-induced transition of the CNCs between a chiral nematic and pseudo-nematic arrangement.
纤维素纳米晶体（CNCs）源自生物质，可自发形成螺旋排列，称为手性向列结构。这种结构模拟了节肢动物外骨骼中甲壳素的组织方式，为其提供了显著的机械强度。在这里，我们展示了一种基于手性向列 CNC 嵌入弹性体中可逆解旋的光子传感机制，使材料表现出对刺激的响应性可拉伸光学性能。当薄膜被拉伸时，会出现鲜明的干涉色，而当弹性体恢复原状时，干涉色会消失。这种可逆光学效应是由 CNCs 在手性向列和拟列之间的机械诱导转变引起的。
