Featuring vertical channel structure through directional solidification method to endow GNP-aerogels with enhanced ultra-electromagnetic wave absorption

Abstract

Three-dimensional (3D) carbon-based electromagnetic waves absorbing materials (EWAMs) have garnered significant attention due to high electrical conductivity, high dielectric loss, low density, and improved characterization of impedance matching. However, there is a paucity of research on the design of material structures. In this regard, we proposed the graphene nanoplates (GNPs) EWAMs featuring a vertically aligned channel structure through liquid nitrogen rapid directional solidification and freeze-drying techniques. By utilizing methyl cellulose (MC) as a binder to modify the internal ice crystal structure, an exceptional electromagnetic waves (EWs) absorption material exhibiting excellent impedance matching characteristics and demonstrating multiple polarization phenomena were created. Notably, the material showcased superior absorption performance with a minimal reflection loss (RLmin) of −57.20 dB. Furthermore, the pre-solidification slurry possesses remarkable plasticity, facilitating the fabrication of various complex structures for EWAMs during directional solidification. This method provides novel insights for future exploration and fabrication of tuneable frequency band EWAMs.