Electromagnetic wave absorption properties of honeycomb structured plasterboards in S and C bands

•Honeycomb structured plasterboards for EM wave absorption were fabricated.•Effects of CB contents and size of honeycomb on reflectivity were studied.•The reflectivity of prepared plasterboard can be less than −10 dB in 2.5–8 GHz.•This study provides a novel design concept for wave absorbing building materials.

This paper provides a feasible way to design honeycomb structured plasterboard for electromagnetic (EM) wave absorption in S and C bands by filling gypsum slurry into carbon black (CB) coated paper honeycomb. The EM wave reflectivity of the prepared plasterboard was investigated by arched testing method, and the influences of CB contents and geometrical parameters of honeycomb structure on the wave absorption were analyzed. The obtained results show that the wave absorption performance of the honeycomb structured plasterboard can be enhanced by increasing the CB content and the honeycomb height, due to the enhancement of dielectric loss capacity and multiple reflections between the honeycomb walls. Moreover, the smaller honeycomb edge length is more conductive to EM wave absorption, because of the increase of the effective permittivity of the honeycomb structured plasterboard. When the edge length and height of honeycomb are 6 mm and 9 mm, respectively, and the CB content is 0.6% in mass, the reflectivity can be less than −10 dB (90% EM wave is absorbed) in the frequency range of 2.5–8 GHz.