Strength and toughness are usually exclusive in polymer nanocomposites with dispersed nanofillers. This intrinsic conflict has been relieved in a high filler loading range by mimicking the nacre structure of natural selection. However, at the low loading extreme, it still remains a great challenge. Here, we design a bicontinuous lamellar (BCL) structure to synergistically reinforce and toughen nanocomposites in the dilute range of nanofiller below 1 wt %. At a typical loading of 0.3 wt %, the BCL composite of graphene oxide (GO) and poly(vinyl alcohol) (PVA) has an 8200% toughness and a comparably reinforced hardness of the dispersed counterpart, accompanying a 53-fold higher failure elongation that even exceeds that of pure PVA. Theoretical modeling and experimental analyses reveal that the continuous generation of massive crazes of GO layers endows the BCL composite with high toughness and surprising breakage elongation beyond those of pure PVA. The BCL organization is an alternatively optimal structure model to merge the exclusive strength and toughness together for damage-tolerant nanocomposites with a dilute range of nanofillers, other than nacre-like and well-dispersed structure, providing an alternative methodology to fabricate mechanically robust composites.

中文翻译：

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人工双连续层压板可协同增强和增强稀石墨烯复合材料的韧性

强度和韧性通常是具有分散的纳米填料的聚合物纳米复合材料所独有的。通过模仿自然选择的珍珠质结构，可以在高填充量范围内缓解这种内在冲突。但是，在低负荷的极端情况下，仍然是一个巨大的挑战。在这里，我们设计了一种双连续层状（BCL）结构，以在小于1 wt％的纳米填料的稀释范围内协同增强和增韧纳米复合材料。在0.3 wt％的典型负载量下，氧化石墨烯（GO）和聚乙烯醇（PVA）的BCL复合材料具有8200％的韧性和相对应的分散体硬度，同时伴随着53倍的更高的断裂伸长率甚至超过了纯PVA。理论建模和实验分析表明，GO层大块状裂纹的连续产生使BCL复合材料具有比纯PVA更高的韧性和惊人的断裂伸长率。BCL组织是一种替代性的最佳结构模型，可以将耐损伤的纳米复合材料与稀薄的纳米填料（除了珍珠母状且分散良好的结构）融合在一起，从而将排他的强度和韧性结合在一起，从而提供了一种替代方法来制造机械坚固的复合材料。