Ag Nanoparticles Embedded in Multishell Carbon Nanoparticles\nfor Microwave Absorption

Abstract

The\ncombination of Ag nanomaterials and special nanostructures\ncan significantly amplify the conversion of electromagnetic energy,\nespecially in microwave absorption applications. Herein, a kind of\nmultishell Ag/C composite nanoparticle with about 635 nm size prepared\nby a self-assembly method was reported, in which the Ag nanoparticles\nwere about 20–40 nm in size. In the process of synthesis, Ag-related\nnanoparticles interfere with the internal cross-linking degree of\nphenolic polymers, and Ag nanoparticles were embedded into multishell\ncarbon nanoparticles after acetone etching and high-temperature calcination.\nStudies have shown that the multishell Ag/C heterogeneous particles\nhave excellent dielectric loss capabilities. By adjusting the Ag content,\nthe dielectric properties and impedance matching characteristics of\nthe particles can be optimized, and thus, the effective absorption\nbandwidth is 5.85 GHz ranging from 12.15 to 18 GHz at only 1.7 mm,\nalmost covering the entire Ku band. The combination of Ag nanoparticles\nand multishell structure can significantly enhance the electromagnetic\nwave attenuation capability, which supplies a serviceable reference\nfor the microstructure and material design of nano-absorbers.