Microwave absorption analysis of graphene-based hybrid nanocomposites: experimental, numerical and component level testing studies

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.