Effects of carbon nanotube alignment on electrical and mechanical properties of epoxy nanocomposites
Effects of carbon nanotube alignment on electrical and mechanical properties of epoxy nanocomposites
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DOI：
10.1016/j.compositesa.2013.01.015
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发表时间：
2013-06-01
影响因子：
8.7
通讯作者：
Kim, Jang-Kyo
中科院分区：
文献类型：
--
作者：
Khan, Shafi Ullah;Pothnis, Jayaram R.;Kim, Jang-Kyo
本文报道了在复合材料固化过程中施加直流电场的结果，多壁碳纳米管（MWCNTs）在环氧树脂基体中的排列。使用光学显微镜和偏振拉曼光谱来确认碳纳米管的排列。与那些具有随机取向的CNT相比，CNT的排列引起大大改善的电导率、弹性模量和准静态断裂韧性。当沿着排列测量时，实现了约0.0031体积%的非常低的电渗流阈值，其比具有随机取向或垂直于排列的CNT测量的0.034体积%低一个数量级以上。断裂表面的检查确定相关的韧化机制在对齐的CNT复合材料，即裂纹尖端偏转和CNT拔出。本文的意义在于，即使在非常低的CNT浓度下，这里采用的技术也可以定制块状纳米复合材料的物理，机械和断裂性能。(C)2013爱思唯尔有限公司保留所有权利。
This paper reports the alignment of multi-walled carbon nanotubes (MWCNTs) in an epoxy matrix as a result of DC electric fields applied during composite curing. Optical microscopy and polarized Raman spectroscopy are used to confirm the CNT alignment. The alignment of CNTs gives rise to much improved electrical conductivity, elastic modulus and quasi-static fracture toughness compared to those with CNTs of random orientation. An extraordinarily low electrical percolation threshold of about 0.0031 vol% is achieved when measured along the alignment, which is more than one order of magnitude lower than 0.034 vol% with random orientation or that measured perpendicular to the aligned CNTs. The examination of the fracture surfaces identifies pertinent toughening mechanisms in aligned CNT composites, namely crack tip deflection and CNT pullout. The significance of this paper is that the technique employed here can tailor the physical, mechanical and fracture properties of bulk nanocomposites even at a very low CNT concentration. (C) 2013 Elsevier Ltd. All rights reserved.