Microstructure and microwave absorbing properties of reduced graphene oxide/Ni/multi-walled carbon nanotubes/Fe3O4 filled monolayer cement–based absorber

Abstract

In this article, reduced graphene oxide/Ni/multi-walled carbon nanotubes/Fe3O4 filled paste is synthesized with the aim of developing a novel shielding material. To do so, nano-dispersion presenting homogeneous distribution is made by ultrasonic dispersing technology. Next, the effects of nano-absorbent content on the fluidity, mechanical strength, pore structure, resistivity, and absorbing reflectivity of paste are studied. At the end, the microstructure of composite is uncovered by scanning electron microscopy, Fourier transformer infrared, X-ray diffraction images as well as the pore size distribution and absorbing reflectivity are revealed. The results indicate that a small load of reduced graphene oxide and other nano-absorbents can significantly reduce the fluidity and resistivity of paste, but its pore structure is improved so that its mechanical properties are increased. Scanning electron microscopy images indicate that reduced graphene oxide promotes the increasing and thickening of the cement hydration products as well as the growth of a large number of flower-like and compact bulk crystals. Furthermore, the minimum reflectivity of −10.6 dB is obtained in the range of 2–18 GHz while the effective bandwidth of 16 GHz is obtained when reflectivity is less than −5 dB. This research provides a new pathway for the preparation of monolayer cement–based absorber.