Liu Senping, Liu Jingran, Xu Zhen, Liu Yilun, Li Peng, Guo Fan, Wang Fang, Liu Yingjun, Yang Mincheng, Gao Weiwei, Gao Chao
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province , Zhejiang University , 38 Zheda Road , Hangzhou 310027 , P. R. China.
State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace , Xi'an Jiaotong University , Xi'an 710049 , China.
ACS Nano. 2018 Nov 27;12(11):11236-11243. doi: 10.1021/acsnano.8b05835. Epub 2018 Oct 23.
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.
在具有分散纳米填料的聚合物纳米复合材料中，强度和韧性通常是相互排斥的。通过模拟自然选择的珍珠层结构，这种内在冲突在高填料负载范围内得到了缓解。然而，在低负载极端情况下，这仍然是一个巨大的挑战。在此，我们设计了一种双连续层状（BCL）结构，以在低于1 wt%的纳米填料稀释范围内协同增强和增韧纳米复合材料。在典型的0.3 wt%负载下，氧化石墨烯（GO）和聚乙烯醇（PVA）的BCL复合材料具有8200%的韧性和与分散对应物相当的增强硬度，同时其断裂伸长率高出53倍，甚至超过了纯PVA。理论建模和实验分析表明，GO层大量银纹的持续产生赋予了BCL复合材料高韧性和令人惊讶的断裂伸长率，超过了纯PVA。BCL结构是一种替代的最优结构模型，用于将相互排斥的强度和韧性融合在一起，以制备具有稀释纳米填料范围的耐损伤纳米复合材料，而不是类珍珠层和良好分散的结构，为制造机械坚固的复合材料提供了一种替代方法。
