Abstract The hierarchical composites integrated by micro-/nano-fillers have been considered to be the multifunctional materials of the next generation. However, the effects of the hierarchical architecture on the electrical properties of composites remains poorly understood. Here, the fabrication of polymer-based multiscale composites with hollow glass fibers coated by carbon nanotubes (CNTs) and the investigation of their morphology, conductivity and dielectric properties are reported. Owing to CNTs introduced into the interfaces, various electrical parameters of the composites are obviously improved. The composite exhibits a stronger anisotropy than that of carbon fiber or CNTs filled composites and an ultralow percolation threshold. These unique behaviors are shown to be related to the hierarchical morphology giving rise to the existence of two percolation levels with different thresholds: a local threshold in the nanoscale CNT networks at the fiber-polymer interfaces and a global threshold in 3D network formed by the fibers. Furthermore, we find and explain some behaviors uncharacteristic of binary composites and the other hierarchical composites. This work provides a deeper understanding of the relationship between the structure and properties of multiscale composites and other complex percolating systems, potentially opening up new ways for designing novel materials.

中文翻译：

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分级结构对碳纳米管涂层改性多尺度复合材料电性能和渗流行为的影响

摘要 微/纳米填料集成的分层复合材料被认为是下一代多功能材料。然而，分层结构对复合材料电性能的影响仍然知之甚少。在这里，报道了用碳纳米管 (CNT) 涂覆的中空玻璃纤维制造聚合物基多尺度复合材料，并研究了它们的形态、导电性和介电性能。由于在界面中引入了碳纳米管，复合材料的各种电学参数得到明显改善。该复合材料表现出比碳纤维或碳纳米管填充复合材料更强的各向异性和超低渗透阈值。这些独特的行为被证明与分层形态有关，导致存在两个具有不同阈值的渗透水平：纤维-聚合物界面处纳米级 CNT 网络的局部阈值和由纤维形成的 3D 网络的全局阈值. 此外，我们发现并解释了一些不符合二元复合材料和其他分层复合材料的行为。这项工作提供了对多尺度复合材料和其他复杂渗透系统的结构和性能之间关系的更深入理解，可能为设计新型材料开辟了新途径。我们发现并解释了一些不符合二元复合材料和其他分层复合材料的行为。这项工作提供了对多尺度复合材料和其他复杂渗透系统的结构和性能之间关系的更深入理解，可能为设计新型材料开辟了新途径。我们发现并解释了一些不符合二元复合材料和其他分层复合材料的行为。这项工作提供了对多尺度复合材料和其他复杂渗透系统的结构和性能之间关系的更深入理解，可能为设计新型材料开辟了新途径。