Multiscale modeling of nonlinear electric conductivity in graphene-reinforced nanocomposites taking into account tunnelling effect
Multiscale modeling of nonlinear electric conductivity in graphene-reinforced nanocomposites taking into account tunnelling effect
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DOI：
10.1016/j.jcp.2017.01.063
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发表时间：
2017-05-15
影响因子：
4.1
通讯作者：
Bai, Jinbo
中科院分区：
文献类型：
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作者：
Lu, Xiaoxin;Yvonnet, Julien;Bai, Jinbo
隧道效应可能是解释石墨烯增强聚合物基纳米复合材料具有明显的大电导率和非线性电行为的机制。在这项工作中，提出了一个数值模拟框架来评估石墨烯片增强聚合物复合材料的有效导电性，考虑到电隧穿效应，这使得石墨烯片之间在纳米距离上导电。我们引入了一个非线性有限元公式和数值方法来模拟由石墨烯片之间的聚合物基体内的隧道效应和传导模型引入的非局部和非线性效应。此外，为了避免对石墨烯片的厚度进行网格化，并考虑到其非常高的纵横比，采用了高导电性表面模型。计算的有效电导率在含有任意分布石墨烯片的代表性体积元素上进行评估。结果显示出的趋势和渗透阈值与现有的实验结果在定性上一致。(C) 2017爱思唯尔公司版权所有。
Tunnelling effect is a possible mechanism to explain the apparent large electric conductivity and nonlinear electric behavior of graphene-reinforced nanocomposites with polymer matrix. In this work, a numerical modeling framework is proposed to evaluate the effective electric conductivity in polymer composites reinforced with graphene sheets, taking into account the electrical tunnelling effect, which allows conduction between graphene sheets at nanometric distances. We introduce a nonlinear Finite Element formulation and a numerical methodology to model the nonlocal and nonlinear effects introduced by the tunnelling effect conduction model within the polymer matrix between close graphene sheets. In addition, to avoid meshing the thickness of the graphene sheets and in view of their very high aspect ratio, a highly conducting surface model is employed. The computed effective conductivity is evaluated over representative volume elements containing arbitrary distributed graphene sheets. The results exhibit tendencies and percolation thresholds which are in qualitative agreement with the available experimental results. (C) 2017 Elsevier Inc. All rights reserved.