Xu Wenwen, Sanchez David M, Raucci Umberto, Zhou Hantao, Dong Xinning, Hu Mingqiu, Bardeen Christopher J, Martinez Todd J, Hayward Ryan C
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA.
Sichuan University-Pittsburgh Institute, Sichuan University, Chengdu, China.
Nat Mater. 2023 Sep;22(9):1152-1159. doi: 10.1038/s41563-023-01610-4. Epub 2023 Jul 27.
Photomechanical crystals composed of three-dimensionally ordered and densely packed photochromes hold promise for high-performance photochemical actuators. However, bulk crystals with high structural ordering are severely limited in their flexibility, resulting in poor processibility and a tendency to fragment upon light exposure, while previous nano- or microcrystalline composites have lacked global alignment. Here we demonstrate a photon-fuelled macroscopic actuator consisting of diarylethene microcrystals in a polyethylene terephthalate host matrix. These microcrystals survive large deformations and show a high degree of three-dimensional ordering dictated by the anisotropic polyethylene terephthalate, which critically also has a similar stiffness. Overall, these ordered and compliant composites exhibit rapid response times, sustain a performance of over at least hundreds of cycles and generate work densities exceeding those of single crystals. Our composites represent the state-of-the-art for photochemical actuators and enable properties unattainable by single crystals, such as controllable, reversible and abrupt jumping (photosalient behaviour).
由三维有序且紧密堆积的光致变色材料组成的光机械晶体有望用于高性能光化学致动器。然而，具有高结构有序性的块状晶体在柔韧性方面受到严重限制，导致加工性能差且在光照下容易破碎，而先前的纳米或微晶复合材料缺乏整体取向。在此，我们展示了一种由聚对苯二甲酸乙二酯主体基质中的二芳基乙烯微晶组成的光子驱动宏观致动器。这些微晶能够承受大变形，并呈现出由各向异性聚对苯二甲酸乙二酯决定的高度三维有序性，至关重要的是，聚对苯二甲酸乙二酯也具有相似的刚度。总体而言，这些有序且柔顺的复合材料具有快速响应时间，能维持至少数百次循环以上的性能，并且产生的功密度超过单晶。我们的复合材料代表了光化学致动器的最新技术水平，并具备单晶无法实现的性能，例如可控、可逆和突然跳跃（光突出行为）。
