Abstract In this work, we proposed a multiscale numerical model to estimate the electric conductivity and dielectric constants of the CNT/polymer nanocomposites, taking into account the tunneling effect between neighbouring CNTs separated at nanoscale and the frequency-dependent dielectric properties of each components. Finite element method was employed to solve the formulations, and the CNTs were modeled by highly conductive line segments in order to avoid the mesh problems. Experiments have been carried out in carbon nanotubes/epoxy nanocomposites in order to compare to the simulation results. The numerical estimations of the electric conductivity are in good agreement with the experimental measurement by network analyzers. Moreover, the calculated dielectric permittivity agrees with the experimental data for the nanocomposites whose CNT content is beyond percolation threshold. Below percolation threshold, the proposed model also works well in the prediction of dielectric constants when the frequency is over 1 0 3 Hz .

中文翻译：

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碳纳米管/聚合物纳米复合材料的交流电导率和介电性能的数值模拟和实验表征

摘要 在这项工作中，我们提出了一个多尺度数值模型来估计 CNT/聚合物纳米复合材料的电导率和介电常数，同时考虑到在纳米尺度上分离的相邻 CNT 之间的隧道效应以及每个组件的频率相关介电特性。采用有限元方法求解公式，并通过高导电线段对碳纳米管进行建模以避免网格问题。为了与模拟结果进行比较，已经在碳纳米管/环氧树脂纳米复合材料中进行了实验。电导率的数值估计与网络分析仪的实验测量非常吻合。而且，计算出的介电常数与碳纳米管含量超过渗透阈值的纳米复合材料的实验数据一致。低于渗透阈值，当频率超过 1 0 3 Hz 时，所提出的模型也能很好地预测介电常数。