Microstructure and Microwave Absorption Properties of Cement-Based Material Reinforced with Reduced Graphene Oxide and Nanoparticles

Microwave absorption properties of paste reinforced with well-dispersed reduced graphene oxide, ferroferric oxide and nickel nanoparticles were investigated. The effect of nanofiller on the fluidity, mechanical properties and pore structure of the paste was studied. The microstructure of the composite is examined by scanning electron microscopy, its groups and hydration products are analyzed with infrared spectra and X-ray diffraction curves. A small nanofiller load is shown to significantly reduce the paste fluidity, but its pore structure is improved so that its mechanical properties are enhanced. Microscopic examination demonstrates that the nanofiller fosters the development of flower-like crystals, which promotes the paste compaction. A minimum reflectivity of -14.7 dB is in the range of 1–18 GHz and the effective bandwidth of 14.4 GHz is obtained when the reflectivity is less than -5 dB. The new method of preparing cement-based absorbent materials is proposed.