Biological materials have the ability to withstand extreme mechanical forces due to their unique multilevel hierarchical structure. Here, we fabricated a nacre-mimetic nanocomposite comprised of silk fibroin and graphene oxide that exhibits hybridized dynamic responses arising from alternating high-contrast mechanical properties of the components at the nanoscale. Dynamic mechanical behavior of these nanocomposites is assessed through a microscale ballistic characterization using a 7.6 μm diameter silica sphere moving at a speed of approximately 400 m/s. The volume fraction of graphene oxide in these composites is systematically varied from 0 to 32 vol % to quantify the dynamic effects correlating with the structural morphologies of the graphene oxide flakes. Specific penetration energy of the films rapidly increases as the distribution of graphene oxide flakes evolves from noninteracting, isolated sheets to a partially overlapping continuous sheet. The specific penetration energy of the nanocomposite at the highest graphene oxide content tested here is found to be significantly higher than that of Kevlar fabrics and close to that of pure multilayer graphene. This study evidently demonstrates that the morphologies of nanoscale constituents and their interactions are critical to realize scalable high-performance nanocomposites using typical nanomaterial constituents having finite dimensions.

中文翻译：

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珍珠母模拟氧化石墨烯和丝纳米复合材料的极端机械行为

由于其独特的多层结构，生物材料具有承受极端机械力的能力。在这里，我们制备了一种由丝素蛋白和氧化石墨烯组成的类似珍珠质的纳米复合材料，该复合材料表现出由纳米级组分的交替高对比度机械性能引起的杂化动态响应。这些纳米复合材料的动态力学行为是通过使用直径为7.6μm的二氧化硅球以约400 m / s的速度移动进行的微型弹道表征来评估的。这些复合物中氧化石墨烯的体积分数从0到32 vol％系统地变化，以量化与氧化石墨烯薄片的结构形态相关的动态效应。随着氧化石墨烯薄片的分布从非相互作用的隔离片发展为部分重叠的连续片，薄膜的比穿透能迅速增加。发现在此处测试的最高氧化石墨烯含量下，纳米复合材料的比穿透能显着高于凯夫拉尔织物的比穿透能，并且接近纯多层石墨烯的比穿透能。这项研究显然证明，纳米级成分的形态及其相互作用对于使用具有有限尺寸的典型纳米材料成分实现可扩展的高性能纳米复合材料至关重要。发现在此处测试的最高氧化石墨烯含量下，纳米复合材料的比穿透能显着高于凯夫拉尔织物的比穿透能，并且接近纯多层石墨烯的比穿透能。这项研究显然证明，纳米级成分的形态及其相互作用对于使用具有有限尺寸的典型纳米材料成分实现可扩展的高性能纳米复合材料至关重要。发现在此处测试的最高氧化石墨烯含量下，纳米复合材料的比穿透能显着高于凯夫拉尔织物的比穿透能，并且接近纯多层石墨烯的比穿透能。这项研究显然证明，纳米级成分的形态及其相互作用对于使用具有有限尺寸的典型纳米材料成分实现可扩展的高性能纳米复合材料至关重要。