Easy Fabrication and Resistivity-Temperature Behavior of an Anisotropically Conductive Carbon Nanotube-Polymer Composite
Easy Fabrication and Resistivity-Temperature Behavior of an Anisotropically Conductive Carbon Nanotube-Polymer Composite
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DOI：
10.1021/jp9042396
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发表时间：
2010-01-21
影响因子：
3.3
通讯作者：
Zhang, Xiao-Na
中科院分区：
文献类型：
--
作者：
Li, Bo;Zhang, Yi-Chuan;Zhang, Xiao-Na
采用狭缝模挤压-热拉伸-淬火工艺制备了填充各向异性导电聚合物复合材料（ACPC）的碳纳米管。将CNTs先与聚碳酸酯（PC）混凝预混，再与聚乙烯（PE）熔融混合。在挤压过程中，对CNT/PC/PE复合材料进行热拉伸，使CNT/PC相在PE基体中原位形成定向导电纤维组装体。最后对排列整齐的CNT/PC短原纤维进行淬火以保持其结构。所得CNT/PC/PE复合材料在电导率方面表现出很强的各向异性。这种方法的优点是提供了一个高度定向的结构，具有良好的电各向异性控制以及以高速率制造的能力。通过观察等温处理（IT）和非等温处理（NIT）过程中的电阻率，研究了其温度电阻率行为。在180°c的第一次IT中，在孤立方向上观察到渗透行为，这是无序诱导的导电网络的结果。此外，正温度系数（PTC）效应随IT时间的延长而减弱。这与剩余的负温度系数（NTC）形成对比。PTC和NTC效应的独特演变源于ACPC特殊的导电网络。可以看出，这是由原本相连的“内在通路”和孤立的“潜在通路”组成的。
An easy fabrication method comprising a slit die extrusion-hot stretch-quench process was used to make carbon nanotubes (CNTs) filled with anisotropically conductive polymer composite (ACPC). CNTs were first premixed with polycarbonate (PC) by coagulation and then melt mixed with polyethylene (PE). During extrusion, the CNT/PC/PE composite was subjected to hot stretching to make the CNT/PC phase form in situ an oriented conductive fibril assembly in the PE matrix. Finally the aligned CNT/PC short fibrils were quenched to preserve their structure. The resultant CNT/PC/PE composite exhibited strong anisotropy in conductivity. This method has the advantages of giving a highly oriented structure with good control of electrical anisotropy as well as the ability to be fabricated in a high rate manner. Temperature-resistivity behavior was investigated by observing the resistivity during isothermal treatment (IT) as well as nonisothermal treatment (NIT). Percolation behavior was seen in the isolated direction during the first IT at 180 degrees C. This was a result of a disordering-induced conductive network. In addition, the positive temperature coefficient (PTC) effect attenuated with IT duration. This was seen in contrast to the remaining negative temperature coefficient (NTC). The unique evolution of PTC and NTC effects originated from the ACPC's special conductive network. It can be seen that this is composed of the originally connected "intrinsic pathway" and isolated "potential pathway".