Interfacial shear stress transfer at nanowire-polymer interfaces with van der Waals interactions and chemical bonding
Interfacial shear stress transfer at nanowire-polymer interfaces with van der Waals interactions and chemical bonding
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DOI：
10.1016/j.jmps.2019.03.013
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发表时间：
2019-06
影响因子：
5.3
通讯作者：
F. R. Poblete;Yong Zhu
中科院分区：
文献类型：
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作者：
F. R. Poblete;Yong Zhu
纳米结构和基质之间的界面力学对于纳米结构的一系列器件应用至关重要。然而，它是具有挑战性的，以表征在这样的纳米界面的界面剪切应力传递。在这项工作中，我们报告了一种新的方法来研究的界面剪切应力转移的单硅纳米线的顶部的聚合物衬底进行单轴拉伸载荷。原位原子力显微镜（AFM）测试用于测量纳米线变形，更具体地说，测量平均轴向应变，作为施加到衬底的应变的函数。两种类型的基板，作为制备和化学处理，被选择来检查的货车范德华相互作用和化学键合的效果。研究发现，非线性和双线性粘滞剪滞模型可以很好地捕捉界面剪应力传递特性与这两种类型的相互作用，分别。对于每一种类型，界面参数，如界面刚度，剪切强度，和/或断裂韧性确定通过拟合实验结果。这项工作提供了有价值的洞察界面剪切滞后模型的基本机制。此外，还对不同纳米线尺寸下的参数进行了研究，为硅纳米线的弹性应变工程和断裂实验设计提供了指导。
Interfacial mechanics between nanostructures and matrix is of critical importance for a range of device applications of the nanostructures. However, it is challenging to characterize interfacial shear stress transfer at such nanoscale interfaces. In this work, we report a new method to study the interfacial shear stress transfer of single Si nanowires on top of a polymer substrate that is subjected to uniaxial tensile loading. In-situ atomic force microscopy (AFM) testing is used to measure the nanowire deformation, more specifically, average axial strain, as a function of the applied strain to the substrate. Two types of substrates, as-prepared and chemically treated, are selected to examine the effect of van der Waals interactions and chemical bonding. It is found that nonlinear and bilinear cohesive shear-lag models can well capture the interfacial shear stress transfer characteristics associated with the two types of interactions, respectively. For each type, the interface parameters such as interfacial stiffness, shear strength, and/or fracture toughness are identified by fitting the experimental results. This work provides valuable insights into fundamental mechanisms underlying the interfacial shear-lag models. In addition, a parametric study with different nanowire dimensions is carried out, which can provide a guide to experimental design of elastic strain engineering and fracture of Si nanowires.