Huang Jie, He Guangyu, Hu Yuxiong, Sun Yiwei, Wang Dongfu, Wang Zhu-Jun, Liu Xueyang, Chen Hongyu
Institute of Advanced Synthesis (IAS) and School of Chemistry and Molecular Engineering Jiangsu National Synergetic Innovation Centre for Advanced Materials Nanjing Tech University Nanjing 211816 P. R. China.
Research Institute of Zhejiang University-Taizhou Taizhou 318000 P. R. China.
Small Sci. 2022 Dec 1;3(1):2200069. doi: 10.1002/smsc.202200069. eCollection 2023 Jan.
It is a great challenge to study the mechanical property of nanomaterials because it is difficult to get a hold of them and apply force. A convenient alternative method via electrospun fibers is shown, where silica-coated fivefold twinned silver nanowires are well aligned in the fiber and the fibers are aligned in the membrane to a similar direction of macroscopic stretching. The product silver nanowires show necks whereas the fractured silica shell acts as the internal marker for the extent of stretching. Surprisingly, the stretched neck length depends on the nanowire diameter but is independent of the degree of stretching, indicating that the necks have arrived at a limiting intermediate state, which is otherwise hard to achieve for nanomaterials. The necks are studied by transmission electron aberration-corrected microscopy and steered molecular dynamics simulation, revealing that the build-up of dislocations and stacking faults (the Lomer-Cottrell (LC) locks) are responsible for trapping the necks at similar limiting states.
研究纳米材料的力学性能是一项巨大的挑战，因为很难获取并对其施加力。本文展示了一种通过电纺纤维的便捷替代方法，其中二氧化硅包覆的五重孪晶银纳米线在纤维中排列良好，并且纤维在膜中沿宏观拉伸的相似方向排列。产物银纳米线出现了颈缩，而破裂的二氧化硅壳作为拉伸程度的内部标记。令人惊讶的是，拉伸后的颈缩长度取决于纳米线直径，而与拉伸程度无关，这表明颈缩已达到极限中间状态，而这对于纳米材料来说通常很难实现。通过透射电子像差校正显微镜和分子动力学模拟对颈缩进行了研究，结果表明位错和堆垛层错（洛默 - 科特雷尔（LC）锁）的形成导致颈缩处于相似的极限状态。
