Controllable Fabricating Dielectric–Dielectric SiC@C Core–Shell Nanowires for High-Performance Electromagnetic Wave Attenuation

Abstract

Heterostructured dielectric-dielectric nanowires of SiC core and carbon shell (SiC@C) with high-performance electromagnetic wave absorption were synthesized by combining an interfacial in situ polymer encapsulation and carbonization process. This approach overcomes the shortcomings of previous reported methods to prepare carbon shell that both carbon shell and free carbon particles are formed simultaneously. In our developed approach, the core of SiC nanowires are first positively charged. Then the negative resorcinol-formaldehyde polymers as the carbon source are anchored on SiC nanowires under the attraction of electrostatic force, which well suppresses the nucleation of free carbon particles. The thickness of the carbon shell could be modulated from 4 to 20 nm by simply adjusting the moral ratio of resorcinol to SiC nanowires. The resulting SiC@C core-shell nanostructures without free carbon particles offer synergism among the SiC nanowires and the carbon shells, generating multiple dipolar polarization, surfaced polarization, and associated relaxations, which endow SiC@C hybrid nanowires with a minimum reflection loss (R) value of -50 dB at the frequency of 12 GHz and an effective absorption bandwidth of 8 GHz with R value under -10 dB at the optimized state. Our results demonstrate that SiC@C hybrid nanowires are promising candidates for electromagnetic wave absorption applications.

1D Organic Micro/Nanostructures for Photonics

“…[ 1–5 ] Due to its significant advantages in size control, high aspect ratio, physical and chemical properties, in recent years, it attracts wide attention in emerging applications such as optical logic gates, coherent light sources, bio‐sensors, and flexible displays. [ 6–9 ] There are many different types of micro/nanostructures existed, mainly including metallic, [ 10–12 ] semiconducting (including inorganic and organic) [ 7,13,14 ] and dielectric wires, [ 15–17 ] where organic ones have been of more and more interests, due to their different intrinsic optoelectronic characteristics. [ 18 ] For example, organic molecular materials relying on intermolecular interactions (such as π–π interaction, hydrogen bond, halogen bond, and so on) can exhibit a wide range emission from the ultraviolet to the near‐infrared.…”

Dielectric loss behavior and microwaves absorption properties of TiB2 ceramic

“…Reduced graphene oxide (RGO) exhibits an enhanced dielectric loss ability toward microwaves at elevated temperature, but is easily oxidized at atmosphere [20]. It is widely considered that silicon carbide (SiC) is a good candidate for design of MA materials with high thermostability, high strength, as well as high oxidation and corrosion resistance [37,38]. However, the application of SiC in MA area is greatly limited on account of its low electrical conductivity [39].…”

Impact of Fluorination on Microstructures and Surface Properties of SiC Nanocomposites with SixCyFz Composition

“…To achieve the efficiency of silicon carbide, many dopants especially transitional metal ions such as iron and cobalt have been used. 6,7,15,18,19 In this report, we wish to investigate and understand the effect of fluorine via in situ doping during the formation of SiC. The study of effects of fluorination has been better reported in silicon nanowires than in silicon carbide nanowires (SiCNWs).…”