Cement-based composites endowed with novel functions through controlling interface microstructure from Fe3O4@SiO2 nanoparticles

In this paper, Fe3O4@SiO2 nanoparticles (NPs) were introduced in the surface layer of cement-based materials derived by magnetic field to create a wave adsorbing layer. The cement-based materials treated with Fe3O4@SiO2 NPs revealed superior microwave-absorption property comparing with the samples treated with pure Fe3O4 NPs. Because of a SiO2 coating on Fe3O4 NPs, water absorption rates of cement mortars treated with Fe3O4@SiO2 NPs have reduced by 45.3%. In addition, the SiO2 coating on Fe3O4 NPs bonded wave absorbing materials on the surface of cement-based composites by forming a mass of SiO2 and calcium silicate hydrate (C-S-H) gels. The Fe3O4@SiO2 NPs can be considered as an ideal wave absorption surface-treatment agent for cement-based composites.