Interface coupling induced microwave absorption enhancement in the C/Fe3O4/halloysite micro-spheres composites

Interfacial coupling in the multi-component composites materials, especially the multifunctional composites, is one of the decisive factors for microwave (MW) absorbing performances of the MW shielding materials. Herein, we report the interface coupling manipulation and so as to the adjustment of permittivity matching of a novel tri-component material with good MW absorption ability. Firstly, halloysite microspheres (Hals) were prepared through a controlled spray drying process, then ferric oxide (Fe3O4) nanoparticles were precipitated onto the Hals, followed by in situ carbonize of the polymerized phenolic resin onto the Hals/Fe3O4 to obtain a ternary components composite. Interfaces were manipulated through adjusting the resource contents and preparation processes. The products were characterized by XRD, SEM, TEM, RAMAN, XPS, VSM spectra, and vector network analyzer. Under carefully controlled conditions, the maximum reflection loss (RLmax) of the Hals/Fe3O4/C composites reached up to −44.3 dB when the thickness is only 1.8 mm, and the RLmax value reached −51.5 dB when the thickness is 4.56 mm. The remarkable microwave absorption performances and simple preparation process make the Hals/Fe3O4/C composites have great potential in MW absorption applications.