Graphene-Coated Honeycomb for Broadband Lightweight Absorbers

The development of lightweight microwave absorber, operating in a wide range of frequencies, is still a challenging task. A novel broadband lightweight radar absorbing material is developed using a phenolic aramid honeycomb (HC) coated with a graphene-filled polymeric paint, which is made of a colloidal suspension of graphene nanoplatelets (GNPs) dispersed in a mixture of polyvinyl-alcohol, water, and 1-propanol. This study describes the production process of the GNP-filled paint and of the lossy HC, and investigates the morphological and electromagnetic properties of the new nanostructured material. A multiscale effective-medium model of the GNP-coated HC, which takes into account the morphology and properties of the nanostructured material from micro to macroscale, is developed and validated through the comparison with experimental data in the X-band. Findings demonstrate a feasible way to develop lightweight and broadband absorbers for various practical applications.