化学气相沉积法制备同轴核壳结构CNTs@SiC的电磁特性研究

以Si单质和功能化多壁碳纳米管(CNTs)为原料,采用化学气相沉积法(CVD)制备了CNTs@SiC同轴核壳结构复合吸波剂。CNTs@SiC的一维管状核壳结构有利于提高材料的介电性能和调节阻抗匹配性能,并能有效提高CNTs的初始氧化温度。Si与CNTs质量比是影响此复合材料电磁特性的关键参数,当m(Si) : m(CNTs) = 1:1.5时,复合材料有最好的吸波性能,当其厚度为1.7mm时,反射率小于-10dB所对应的有效带宽达到4.8GHz；当m(Si) : m(CNTs) = 1:2时,材料在X波段有最好的吸波效果,有效带宽达3GHz。所制备的CNTs@SiC复合材料不仅在常温下具有宽频强吸收的特点,其独特的一维管状核壳结构有望使材料在高温环境下仍具有优异的吸波性能。

Electromagnetic Properties of Coaxial Core-shell CNTs@SiC Prepared by Chemical Vapor Deposition

CNTs@SiC Coaxial Core-shell composite absorber was prepared by chemical vapor deposition (CVD) with monatomic silicon and functionalized multi-walled carbon nanotubes (CNTs). The one-dimensional tubular core-shell structure of CNTs@SiC is conducive to the improvement of dielectric properties and the adjustment of impedance matching performance, and effectively improves the initial oxidation temperature of CNTs. The mass ratio of Si to CNTs is a key parameter affecting electromagnetic properties of the composite. When m (Si): m (CNTs) = 1:1.5, the composite has the best absorbing performance. The effective bandwidth reaches 4.8GHz when the thickness is 1.7mm. When m (Si): m (CNTs) = 1:2, the material has the best absorbing effect in X band, with effective bandwidth up to 3GHz. The CNTs@SiC composite absorber not only has excellent absorbing effect at normal temperature, but also is expected at high temperature due to its unique one-dimensional cored-shell structure.