Lightweight and Flexible Graphene Foam Composites for High-Performance Electromagnetic Interference Shielding
Lightweight and Flexible Graphene Foam Composites for High-Performance Electromagnetic Interference Shielding
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用于高性能电磁干扰屏蔽的轻质柔性石墨烯泡沫复合材料
DOI：
10.1002/adma.201204196
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发表时间：
2013-03-06
影响因子：
29.4
通讯作者：
Cheng, Hui-Ming
中科院分区：
文献类型：
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作者：
Chen, Zongping;Xu, Chuan;Cheng, Hui-Ming
随着现代电子技术的飞速发展，集成电路的高度集成化，产生了严重的电磁辐射，对高灵敏度的精密电子设备和人类的生存环境造成了严重的危害。高性能电磁干扰屏蔽材料的开发一直是电磁屏蔽领域的研究热点。除了高EMI屏蔽性能之外，轻量化和柔性是有效和实用的EMI屏蔽应用的另外两个重要技术要求，特别是在飞机，航空航天，汽车和快速增长的下一代柔性电子产品（如便携式电子产品和可穿戴设备）领域。[1]最近，导电聚合物复合材料在EMI屏蔽应用中受到了广泛关注[1-12]，因为与传统的金属基材料相比，它们重量轻，耐腐蚀，柔韧性，良好的加工性和低成本。聚合物复合材料的EMI屏蔽效能主要取决于固有的电导率、介电常数、磁导率、纵横比和导电填料的含量。[1-12]据信，导电填料的高导电性和连接性可以改善EMI屏蔽性能。[1，2，4，7，8]包括碳丝、碳纤维、碳纳米纤维、碳纳米管（CNT）和化学衍生的石墨烯（CDG）的许多碳基材料已经用作导电填料以制造用于EMI屏蔽的复合材料，因为它们的高导电性、优异的机械性能、重量轻、柔性和大纵横比。[1-12]然而，在这些聚合物复合材料中，单个导电碳基填料随机分布在聚合物基体内部，并被聚合物的分子链包围，这些复合材料的导电性强烈依赖于分离的填料颗粒之间的电子渗透。因此，通常需要高含量和良好分散的碳基填料以在绝缘聚合物基体中形成导电互连网络，从而改善复合材料的导电性和EMI屏蔽效能。例如，已经证明，7重量%的多壁CNT，[1] 15重量%的单壁CNT，
The rapid development of modern electronics packed with highly integrated circuits generates severe electromagnetic radiation, which leads to harmful effects on highly sensitive precision electronic equipment as well as the living environment for human beings. Great effort has been made for the development of high-performance electromagnetic interference (EMI) shielding materials. In addition to high EMI shielding performance, being lightweight and flexible are two other important technical requirements for effective and practical EMI shielding applications especially in areas of aircraft, aerospace, automobiles, and fast-growing next-generation flexible electronics such as portable electronics and wearable devices.[1] Recently, electrically conductive polymer composites have received much attention for EMI shielding applications,[1–12] because of their light weight, resistance to corrosion, flexibility, good processability, and low cost compared to the conventional metal-based materials. The EMI shielding effectiveness of the polymer composites depends critically on the intrinsic electrical conductivity, dielectric constant, magnetic permeability, aspect ratio, and content of conductive fillers.[1–12] It is believed that high electrical conductivity and connectivity of the conductive fillers can improve EMI shielding performance.[1, 2, 4, 7, 8]Many carbon-based materials including carbon filaments, carbon fibers, carbon nanofibers, carbon nanotubes (CNTs), and chemically derived graphene (CDG) have been used as conductive fillers to fabricate composite materials for EMI shielding because of their high electrical conductivity, excellent mechanical properties, light weight, flexibility, and large aspect ratio.[1–12] However, in these polymer composites, individual conductive carbon-based fillers are randomly distributed inside the polymer matrix and are surrounded by the molecular chains of the polymer, and the electrical conductivity of these composites strongly relies on electron percolation between the separated filler particles. As a result, a high content and good dispersion of carbon-based fillers are usually required to form a conductive interconnected network in the insulating polymer matrix to improve the electrical conductivity and EMI shielding effectiveness of the composites. For example, it has been demonstrated that 7 wt% multi-walled CNTs,[1] 15 wt% single-walled