Broadband electromagnetic wave absorption cement-based composite using foam-loaded KH550@Fe3O4 nanoparticles

This paper devises a novel approach designed to achieve an optimal distribution of absorbing agent for enhancing the electromagnetic wave (EW) absorption of cement-based composite, introducing KH550@Fe3O4 nanoparticles through foam loading. The effects of foam doping and the thickness of the samples on the EW absorption performance were investigated, and the concept of EW transmission and attenuation mechanism and influencing factors were analyzed. The foam loaded with an absorbing agent was prepared by uniformly dispersing modified nano-Fe3O4 foaming agent and employing physical foaming. This innovative manufacturing method uniformly disperses the absorbing agent along the pore walls of the composite, thereby creating a resonant cavity structure that significantly improves the EW absorption. Excitingly, the composite shows an effective absorption bandwidth of 14.8 GHz. Attributing to the specific porous system and the internal resonant cavities, a synergistic effect of improved impedance matching characteristics and superior EW attenuation was achieved.