In this study, an Epoxy/POSS-liquid crystalline azobenzene-Poly (ethylene-co-vinyl acetate) (Epoxy/POSS-Azo-EVA) composite was prepared via the thermal curing of epoxy monomers and multi-functional thiol-containing Polyhedral oligomeric silsesquioxane (POSS) in an EVA matrix. The EVA matrix afforded the composite with shape memory performance. Epoxy/POSS polymer was uniformly dispersed in the matrix to act as a rigid skeleton, leading to the improvement of the mechanical properties and shape memory performance of the composite. Liquid crystalline azobenzene as the photosensitive component provided the inner stress to render the composite film with photo-induced shape-deformation behavior under UV light. The composite film not only exhibited thermal- and light-responsive programmable shape-memory behavior stimulated by heat and light, but also was recyclable and reprocessable. Moreover, the recycled composite film was processed into different functional devices. A flexible photomechanical device based on the recycled Epoxy/POSS-Azo-EVA composite film was fabricated, and the soft device deformed into a hook-shape under UV light and hooked an object whose weight is larger than that of the device. A smart wire was also prepared via assembling a stretched recycled Epoxy/POSS-Azo-EVA composite film and a copper foil by adhesive. The wire could control the status of a circuit via changing its shape under UV light and maintain the status after the removal of light. The functional devices described in this work only needed a short time of UV irradiation during a work cycle, and the devices still held the temporary shape in the absence of UV irradiation. The recyclable and reprocessable Epoxy/POSS-Azo-EVA composite film in this work could provide a creative approach for the fabrication of novel photomechanical devices and soft robotics with energy-saving, intelligence, recyclability, and sustainability.

中文翻译：

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可回收和可再加工的环氧多面体低聚倍半硅氧烷（POSS）/介晶偶氮苯/聚（乙烯-醋酸乙烯酯）复合材料，具有热响应和光响应可编程形状记忆性能

本研究通过环氧单体与多官能团含硫醇多面体低聚物的热固化制备了环氧/POSS-液晶偶氮苯-聚(乙烯-共-醋酸乙烯酯)(Epoxy/POSS-Azo-EVA)复合材料。 EVA 基质中的倍半硅氧烷 (POSS)。 EVA 基体使复合材料具有形状记忆性能。环氧树脂/POSS聚合物均匀分散在基体中作为刚性骨架，从而提高复合材料的机械性能和形状记忆性能。液晶偶氮苯作为光敏组分提供内应力，使复合膜在紫外光下具有光致形变行为。该复合薄膜不仅表现出受热和光刺激的热响应和光响应可编程形状记忆行为，而且是可回收和可再加工的。此外，回收的复合薄膜被加工成不同的功能器件。制备了一种基于回收Epoxy/POSS-Azo-EVA复合薄膜的柔性光机械器件，该柔性器件在紫外光照射下变形为钩状，并钩住重量大于该器件的物体。还通过将拉伸的回收Epoxy/POSS-Azo-EVA复合膜和铜箔通过粘合剂组装来制备智能线。该导线可以通过在紫外光照射下改变其形状来控制电路的状态，并在光线消失后保持该状态。这项工作中描述的功能器件在一个工作周期中只需要短时间的紫外线照射，并且在没有紫外线照射的情况下，器件仍然保持临时形状。这项工作中的可回收和可再加工的Epoxy/POSS-Azo-EVA复合薄膜可以为制造具有节能、智能、可回收和可持续性的新型光机械设备和软机器人提供一种创造性的方法。