National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal Chemistry, Chinese Academy of Sciences , 27 Taoyuan South Road, Taiyuan 030001, China.
University of Chinese Academy of Sciences , 19 Yuquan Road, Beijing 100049, China.
ACS Appl Mater Interfaces. 2017 Feb 15;9(6):5653-5659. doi: 10.1021/acsami.6b16029. Epub 2017 Feb 2.
The self-stiffening under external dynamic strain has been observed for some artificial materials, especially for nanocomposites. However, few systematic studies have been carried out on their structural evolutions, and the effect of the types of nanofillers was unclear. In this study, we used a semicrystalline polymer, polyacrylonitrile (PAN), and various types of carbon nanomaterials including C, carbon nanotube (CNT), and graphene oxide (GO). An external uniaxial dynamic strain at small amplitude of 0.2% was applied on the prepared nanocomposite films. It was observed that PAN/CNT exhibited significant self-stiffening behavior, whereas PAN/GO showed no response. Systematic characterizations were performed to determine the structural evolutions of PAN/CNT film during dynamic strain testing, and it was found that the external dynamic strain not only induced the crystallization of PAN chains but also aligned CNT along the strain direction.
在外加动态应变下的自增强现象已经在一些人工材料中被观察到，尤其是在纳米复合材料中。然而，对于它们的结构演变，很少有系统的研究，而且纳米填充剂的类型的影响也不清楚。在这项研究中，我们使用了半结晶聚合物聚丙烯腈（PAN）和各种类型的碳纳米材料，包括 C、碳纳米管（CNT）和氧化石墨烯（GO）。在制备的纳米复合材料薄膜上施加了小振幅为 0.2%的外部单轴动态应变。结果发现，PAN/CNT 表现出显著的自增强行为，而 PAN/GO 则没有响应。我们进行了系统的表征来确定 PAN/CNT 薄膜在动态应变测试过程中的结构演变，结果发现，外部动态应变不仅诱导了 PAN 链的结晶，而且还使 CNT 沿着应变方向排列。
