Abstract In this work, DC conductivity and EMI shielding characteristics in the frequency range of 25.5–37.5 GHz (Ka-band) of polymer composites based on ultrahigh-molecular-weight polyethylene (PE) and polypropylene (PP) containing different types of nano- and microfillers were studied. Graphene nanoplatelets (Gr), thermally exfoliated graphite (TEG), thermally treated anthracite (A) and dispersed metals such as iron (Fe) and copper (Cu) were used as conductive fillers. Two types of composites were formed: 1 – with ordered distribution of the filler particles in the form of conductive 3D network in polymer matrix (segregated structure), 2 – with random distribution of the filler particles. It was found that the percolation threshold for Gr and A filler is 100 and 10 times lower in the segregated system was 100 and 10 times lower than that for A filler with its random distribution in polymer matrix. Distinctly increased value of shielding efficiency (SET) in the segregated system can be explained by multiple internal reflection of electromagnetic wave in the network formed in the segregated structure. It was also found that the value of SE corresponds with the electrical conductivity of composites. However, for the same conductivity, higher values of SE were observed for the formed segregated structure in comparison with the literature data for composites with random filler distribution.

中文翻译：

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导电纳米和微填料分布对聚合物/碳复合材料导电性和EMI屏蔽性能的影响

摘要 在这项工作中，基于超高分子量聚乙烯 (PE) 和聚丙烯 (PP) 的聚合物复合材料在 25.5-37.5 GHz（Ka 波段）频率范围内的直流电导率和 EMI 屏蔽特性包含不同类型的纳米级和微填料进行了研究。石墨烯纳米片 (Gr)、热剥离石墨 (TEG)、热处理无烟煤 (A) 和分散的金属如铁 (Fe) 和铜 (Cu) 被用作导电填料。形成了两种类型的复合材料：1 – 填料颗粒在聚合物基体中以导电 3D 网络的形式有序分布（分离结构），2 – 填料颗粒随机分布。结果发现，在分离体系中，Gr 和 A 填料的渗透阈值分别低 100 和 10 倍，比在聚合物基体中随机分布的 A 填料低 100 和 10 倍。隔离系统中屏蔽效率 (SET) 的显着增加值可以通过电磁波在隔离结构中形成的网络中的多次内部反射来解释。还发现 SE 的值与复合材料的电导率相对应。然而，对于相同的电导率，与具有随机填料分布的复合材料的文献数据相比，对于形成的分离结构观察到更高的 SE 值。隔离系统中屏蔽效率 (SET) 的显着增加值可以通过电磁波在隔离结构中形成的网络中的多次内部反射来解释。还发现 SE 的值与复合材料的电导率相对应。然而，对于相同的电导率，与具有随机填料分布的复合材料的文献数据相比，对于形成的分离结构观察到更高的 SE 值。隔离系统中屏蔽效率 (SET) 的显着增加值可以通过电磁波在隔离结构中形成的网络中的多次内部反射来解释。还发现 SE 的值与复合材料的电导率相对应。然而，对于相同的电导率，与具有随机填料分布的复合材料的文献数据相比，对于形成的分离结构观察到更高的 SE 值。