石墨烯基电磁功能材料

二维纳米材料拥有优异的电学、热学和力学性能,在高技术领域展现出巨大的应用潜力。其中,石墨烯具有大的比表面积和高的载流子浓度,是当代科技关注的对象。系统地展示了石墨烯基电磁功能材料的电磁响应机制以及吸波与屏蔽性能。在研究的电磁波频段(2~18 GHz),电磁损耗一般包括电导损耗、多重弛豫、磁共振及磁涡流。详细地介绍了这四种电磁损耗行为的物理形成机制和响应特性,总结了不同石墨烯基电磁功能材料的电磁损耗来源,并提出了设计高性能电磁功能材料的策略。随后,展示了高性能电磁功能材料的应用标准,给出了微波吸收与电磁屏蔽的响应规律,提出了两种改善电磁响应性能的方法。在电磁功能材料性能方面,介绍了石墨烯基电磁功能材料在微波吸收和电磁屏蔽领域最新研究进展。所涉内容涵盖石墨烯单相材料、异质材料及高温介电特性和电磁响应。另外,还系统地分析了石墨烯基电磁功能材料当前发展所面临的关键问题,并展望了未来的研究与发展方向。

Graphene-based Electromagnetic Functional Materials

Two-dimensional nanomaterials possess excellent electrical, thermal and mechanical properties, exhibiting great potential in the electromagnetic field. Among them, graphene has a large specific surface area and a high carrier concentration, which is the focus of contemporary technology. Herein, the electromagnetic response mechanism, wave absorption and shielding properties of graphene-based electromagnetic functional materials are demonstrated systematically. In the electromagnetic frequency band (2~18 GHz) investigated, electromagnetic losses include conduction loss, multiple relaxation, magnetic resonance and magnetic eddy current generally. Here, the physical formation mechanism and response characteristics of these four electromagnetic loss behaviors are introduced in detail, and the sources of electromagnetic loss of different graphene-based electromagnetic functional materials are summarized. The strategies for designing high-performance electromagnetic functional materials are also proposed. Subsequently, the application standards of high performance electromagnetic functional materials are presented. The response laws of microwave absorption and electromagnetic shielding are put forward. Two methods to improve the electromagnetic response performance are also proposed. For the electromagnetic functional material performances, the latest research progress of graphene-based electromagnetic functional materials in microwave absorption and electromagnetic shielding is introduced. The single-phase and heterogeneous graphene materials, high temperature dielectric properties and electromagnetic responses are covered. In addition, the key problems in the current development of graphene-based electromagnetic functional materials are systematically analyzed, and the research and development directions in the future are prospected.