聚合物基石墨烯纤维织物及其层叠结构的电磁屏蔽作用和调控研究

With the rapid development of electronic industries, the electromagnetism jam has become a new public harm. Therefore, design and fabrication of high-performance electromagnetic interference (EMI) shielding materials is one of the most urgent problems needs to be solved. Early studies have confirmed that macroscopic graphene foams and graphene films could effectively utilize the great electrical property of graphene sheets, thereby could serve as high-performance graphene-based EMI shielding materials. Graphene fibers are one-dimensional graphene macroscopic materials, and their excellent electrical conductivity makes them a new alternative for excellent EMI shielding. However, unlike macroscopic graphene foams and graphene films, graphene fibers are difficult to be directly used in practical EMI shielding application, possibly due to their one-dimensional structure. In this research, graphene fibers would be assembled into polymer-coated graphene fiber fabric with two-dimensional mesh structure, and the investigation of how the electrical conductivity of graphene fibers and the macrostructure of the fabric could affect the final shielding performance would be conducted. Moreover, exploring new methods to conveniently tune the shielding performance of the multilayer fabrics with double-stacked structure would also be conducted.

随着现代电子工业的快速发展，各种电磁干扰现象和电磁污染问题日益突出，设计并制备高效电磁屏蔽材料已成为一个迫切需要解决的问题。申请人及其它相关研究者的前期研究已经表明石墨烯泡沫和石墨烯薄膜等石墨烯基宏观材料可以最大程度地发挥石墨烯片层优异的导电性能，是制备高效石墨烯基电磁屏蔽材料的有效途径。石墨烯纤维是石墨烯的一维线性宏观材料，极高的导电能力为其在电磁屏蔽领域提供了极大的应用前景，但是单纯的石墨烯纤维是一维材料，很难直接用于实际电磁屏蔽。在本项目中，申请人拟通过将石墨烯纤维设计并组装成具有二维网格结构的聚合物基石墨烯纤维织物以获得高效石墨烯纤维电磁屏蔽材料，同时揭示石墨烯纤维电导率及织物宏观结构等因素对最终聚合物基石墨烯纤维织物在不同频率段上电磁屏蔽作用的影响规律及影响机制。另外，探索通过简单的层间位移来实现由两层聚合物基石墨烯纤维织物叠加复合而成的层叠结构复合织物的电磁屏蔽性能的有效调控。

本基金内容是研究石墨烯纤维织物的电磁屏蔽作用和调控研究，但是在石墨烯纤维以及纤维织物可控制备过程中存在问题，因此我们另外选择以具有类似结构的碳基纤维及其织物为研究对象，系统研究了电导率及织物宏观结构对材料电磁屏蔽作用的影响规律及影响机制，以及通过简单的层间位移实现层叠结构复合织物电磁屏蔽性能的有效调控。结果表明：升高碳化温度可以提升材料电导率，从而增强电磁波反射而大大提高碳基纤维织物的电磁屏蔽效能，但是增大织物的网格尺寸却会减弱电磁波反射而降低其屏蔽效能；其次，我们在全波模拟软件中为碳基纤维织物构建了电磁模型并进行了对比仿真，结果说明通过制备具有较小波动且具有较少缺陷光滑表面的碳基纤维织物材料可以提升最终屏蔽性能，同时还证明了双层织物样品的屏蔽效能可以通过微小平移运动改变堆叠网格的交错度来方便地调节。另一方面，由于本项目的主要目的是研究材料结构对电磁屏蔽的影响，因此我们还以棉纤维、小麦秸秆、瓦楞纸等为原材料通过碳化并结合石墨烯的方式构建了具有三明治结构、中空多孔碳管阵列结构、瓦楞纸结构的轻质高效碳基屏蔽材料，系统研究了不同结构参数对屏蔽性能的影响，为轻质高效电磁屏蔽材料的设计和制备提供了参考借鉴。