Abstract Biological materials are multifunctional performing more than one function in a perfect synergy. These materials are built from fairly simple and limited components at ambient conditions. Such judicious designs have proven elusive for synthetic materials. Here, we demonstrate a multifunctional phase change (pc) composite from simple building blocks, which exhibits high stiffness and optical transmittance control. We show an increase of more than one order of magnitude in stiffness when we embed paraffin wax spheres into an elastomer matrix, polydimethylsiloxane (PDMS) in a dynamic compression test. High stiffness is mainly influenced by presence of microcrystals within the wax. We further show fast temperature-controlled optical switching of the composite for an unlimited number of cycles without any noticeable mechanical degradation. Through experimental and finite element method, we show high energy absorption capability of pc-composite. Based on these properties, the pc-composite could be used as an effective coating on glasses for cars and windows. This simple approach to multi-functionality is exciting and could pave way for designs of other multifunctional materials at the macro-scale.

中文翻译：

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具有可调透明度的高刚度聚合物复合材料

摘要 生物材料是多功能的，可以完美地协同发挥多种功能。这些材料在环境条件下由相当简单且有限的组件构成。事实证明，这种明智的设计对于合成材料来说是难以捉摸的。在这里，我们展示了由简单的积木制成的多功能相变 (pc) 复合材料，它具有高刚度和光学透射率控制。在动态压缩测试中，当我们将石蜡球体嵌入弹性体基质聚二甲基硅氧烷 (PDMS) 中时，我们的刚度增加了一个数量级以上。高刚度主要受蜡中微晶的影响。我们进一步展示了复合材料的快速温控光学开关，循环次数不受限制，而没有任何明显的机械退化。通过实验和有限元方法，我们展示了 pc 复合材料的高能量吸收能力。基于这些特性，PC 复合材料可用作汽车和窗户玻璃的有效涂层。这种简单的多功能方法令人兴奋，可以为宏观尺度的其他多功能材料的设计铺平道路。