Electrical Conducting Behaviors in Polymeric Composites with Carbonaceous Fillers
Electrical Conducting Behaviors in Polymeric Composites with Carbonaceous Fillers
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DOI：
10.1002/polb.21115
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发表时间：
2007-05
期刊：
影响因子：
--
通讯作者：
Dan Zhu;Y. Bin;M. Matsuo
中科院分区：
文献类型：
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作者：
Dan Zhu;Y. Bin;M. Matsuo
通过凝胶化/结晶过程或熔融混合方法制备了几种含有碳质填料如炭黑（CB）、气相生长碳纤维（CF）和碳纳米管（CNT）的聚合物复合材料。这些碳填充聚合物复合材料中的电学现象、电导率随填料种类、浓度和温度的变化以及电子传输机制直接受到分散在聚合物基体中的填料的几何颗粒形状和聚集形态的影响。对于CB/CF复合材料，长程宏观导电受逾渗现象控制，导电是通过导体接触形成的导电通路进行的，热膨胀改变了整个电网络的物理尺寸，导致电现象的变化。导电元件之间的微观导电受隧穿势垒或隧穿电压的影响，隧穿势垒或隧穿电压随温度变化而变化，解释了复合材料的温度依赖性的明显观察。与CB和CF填料相比，CNT表现出独特的电性能，因为它们的非球形几何形状和形态作为一个三维网络（高结构），这已经在我们以前的研究中通过SEM照片直观地证明，导致其复合材料的渗滤阈值低于1%的体积分数和更小的温度依赖性。Wiley Periodicals，Inc. J Polym
Several kinds of polymer composites with carbonaceous fillers such as carbon black (CB), vapor-grown carbon fiber (CF), and carbon nanotube (CNT) are prepared by a gelation/crystallization process or a melt mixing method. The electrical phenomena, changes of electrical conductivities with different filler's type, filler's concentration and temperatures, and the mechanism of electron transport in these carbon-filled polymer composites are directly influenced by the geometric grain shape and aggregating morphology of the fillers dispersed in the polymer matrix. For the composites of CB and CF, long-range macroscopic conduction are governed by the percolation phenomenon, the conduction is behaved through the conductive path formed by the conductors' contacting, and the ther- mal expansion changes the physical dimensions of the entire electrical network and leads to the changes in the electrical phenomenon. Microscopic conduction between conductive elements is influenced by the tunneling barrier or tunneling voltage, which varies with the temperature change, explaining the apparent observation of the temperature depend- ence of the composites. In comparison with fillers of CB and CF, the CNT performs unique electric properties for their nonspherical geometry and morphology as a three-dimensional network (high structures), which has been visually proved by SEM photos in our former research, leading to the percolation threshold lower than 1% in the volume fraction and much less temperature dependence in its composites. V C 2007 Wiley Periodicals, Inc. J Polym