Wei Yiwei, Chen Kui, Zhu Shanshan, Wu Wenbo, Zhao Hongtu, Huang Xin, Wang Na, Zhou Lina, Wang Ting, Wang Jingkang, Hao Hongxun
National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Small. 2024 Apr;20(14):e2307756. doi: 10.1002/smll.202307756. Epub 2023 Nov 21.
Organic photomechanical molecular crystals are promising candidates for photoactuators, which have potential applications as smart materials in various fields. However, it is still challenging to fabricate photomechanical molecular crystals with flexibility because most of the molecular crystals are brittle and the mechanism of flexible crystals remains controversial. Here, a plastically flexible α-cyanostilbene crystal has been synthesized that can undergo solid-state [2+2] cycloaddition reaction under violet or UV irradiation and exhibits excellent photomechanical bending properties. A hook-shaped crystal can lift 0.7 mg object upward by 1.5 cm, which proves its potential for application as photoactuators. When complex with the agarose polymer, the molecules will be in the form of macroscopic crystals, which can drive the composite films to exhibit excellent photomechanical bending performance. Upon irradiation with UV light, the composite film can quickly lift 18.0 mg object upward by 0.3 cm. The results of this work may facilitate the application of macroscale crystals as photoactuators.
有机光机械分子晶体是光致动器的理想候选材料，在各个领域作为智能材料具有潜在应用。然而，制造具有柔韧性的光机械分子晶体仍然具有挑战性，因为大多数分子晶体是脆性的，并且柔性晶体的机制仍存在争议。在此，合成了一种塑性柔性α-氰基苯乙烯晶体，该晶体在紫光或紫外线照射下可发生固态[2+2]环加成反应，并表现出优异的光机械弯曲性能。一个钩形晶体可以将0.7毫克的物体向上提升1.5厘米，这证明了其作为光致动器的应用潜力。当与琼脂糖聚合物复合时，分子将呈宏观晶体形式，这可以驱动复合膜表现出优异的光机械弯曲性能。在用紫外线照射时，复合膜可以迅速将18.0毫克的物体向上提升0.3厘米。这项工作的结果可能会促进宏观晶体作为光致动器的应用。
