Co/SiO2 composite particles with high electromagnetic wave absorbing performance and weather resistance

Co/SiO 2 composite particles were prepared by fabricating SiO 2 shell on the surfaces of dendritic Co particles. The effects of SiO 2 shell and annealing treatment on microstructure evolution and performance improvement of Co/SiO 2 composite particles were investigated. It was found that, Co/SiO 2 composite particles exhibited weather resistance when exposed to high temperature air or diluted hydrochloric acid. Coatings containing Co/SiO 2 composite particles as fillers presented high electromagnetic wave absorbing efficiency and thin matching thickness. The weather resistance and the electromagnetic wave absorbing performance were further improved after an annealing treatment.