当前位置: X-MOL 学术Math. Mech. Solids › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites
Mathematics and Mechanics of Solids ( IF 2.6 ) Pub Date : 2021-06-14 , DOI: 10.1177/10812865211021460
Xiaodong Xia 1 , George J. Weng 2
Affiliation  

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.



中文翻译:

逐渐团聚的碳纳米管/聚合物纳米复合材料中导电性和电磁干扰屏蔽的双重渗透

最近的实验揭示了碳纳米管 (CNT)/聚合物纳米复合材料中两种不同的渗透现象:一种与导电性有关,另一种与电磁干扰 (EMI) 屏蔽有关。然而,目前似乎没有理论可以同时预测它们的渗透阈值和相关的电导率和 EMI 曲线。在这项工作中,我们提出了一种具有电和磁界面效应的有效介质理论,以计算通常团聚的纳米复合材料的整体电导率,并调用麦克斯韦方程组的解来计算 EMI 屏蔽效果。在这个过程中,采用复电导率和复磁导率两个复量作为均质化参数,并且使用具有富碳纳米管和贫碳纳米管区域的两尺度模型来描述碳纳米管团聚的逐渐形成。我们证明确实存在两种独立的渗透行为,并表明,与聚-L-乳酸(PLLA)/多壁碳纳米管(MWCNT)纳米复合材料的实验数据一致,电渗透阈值较低超过 EMI 屏蔽渗透阈值。预测的电导率和 EMI 屏蔽曲线也与实验数据非常吻合。我们进一步公开了整个 CNT/聚合物纳米复合材料中 EMI 屏蔽的渗透行为可以通过在 CNT 贫乏区域建立连接填料网络来说明。

更新日期:2021-06-14
down
wechat
bug