ABSTRACT

An effective nanocomposite-based microwave absorber made of polyurethane /graphene/glass/epoxy with different weight percentages of graphene (0 to 2.5 wt%) is proposed. Microstructural characterization of samples is done with the help of XRD, FESEM and TEM. Graphene crystalline structure maximum diffraction peak is observed at 26o associated interlayer d-spacing is 0.341 nm (plane 002), the same affirmed with TEM analysis. Graphene flake structure is identified from FESEM results. Firstly, experimental investigation is done using wave guide setup, later numerical model is developed using RF module in COMSOL. The experimental results reveal more than 90% absorption capability in broad bandwidth i.e., 3 GHz and maximum Reflection loss -35.9 dB is attained at 12.1 GHz. Also, maximum shielding effectiveness is -47 dB for 2.5 wt% PU/graphene composite due to its semi conduction. Further, a composite concrete block using 2.5 wt% PU/graphene is analysed using numerical model for the application of anechoic.

摘要

提出了一种有效的基于纳米复合材料的微波吸收器，该吸收器由具有不同重量百分比的石墨烯（0 至 2.5 wt%）的聚氨酯/石墨烯/玻璃/环氧树脂制成。样品的微观结构表征是在 XRD、FESEM 和 TEM 的帮助下完成的。石墨烯晶体结构最大衍射峰出现在26°相关层间d间距为0.341 nm（002面），与TEM分析相同。石墨烯薄片结构由 FESEM 结果确定。首先，使用波导装置进行实验研究，然后使用 COMSOL 中的 RF 模块开发数值模型。实验结果表明，在宽带宽（即 3 GHz）中具有超过 90% 的吸收能力，在 12.1 GHz 时达到 -35.9 dB 的最大反射损耗。此外，2 的最大屏蔽效能为 -47 dB。5 wt% PU/石墨烯复合材料，由于其半导电性。此外，使用数值模型分析了使用 2.5 wt% PU/石墨烯的复合混凝土块的消声应用。