碳纳米管/石英复合材料的电磁波吸收性能

采用溶胶-凝胶法合成了碳纳米管/石英复合粉体, 复合粉体经热压烧结获得致密的复合材料. 在8.2～2.4GHz波段测试了该复合材料的复介电常数, 发现复介电常数随着碳纳米管含量的增加而大幅度提高, 大的介电常数虚部说明该复合材料具有很大的介电损耗. 采用传输线理论计算了该复合材料对电磁波的反射损耗, 发现复合材料在此波段对电磁波具有吸收效果, 并且反射损耗 与复合材料的厚度、碳纳米管体积含量具有密切的关系. 本文还采用了层状设计的方法提高了复合材料的吸波性能.

Electromagnetic Wave Absorption Properties of Carbon Nanotube-Fused Silica Composites

Carbon nanotube-fused silica composite powders were synthesized by a sol-gel method, and then the composite powders were hot-pressed to obtain relatively dense composites. Complex permittivity spectra of these composites were obtained at 8-12GHz. The experimental results show that the complex permittivity increases as the volume content of carbon nanotube increases in the measured frequency region. High imaginary permittivity reveals that these composites exhibit considerable dielectric loss. Refection loss of these composites calculated with transmission-line theory shows that these composites have obvious electromagnetic wave absorption ability and the reflection loss is sensitively relative to the thickness of composites and the volume content of carbon nanotube. The absorption properties of the composites are also improved by designing two-layer carbon nanotube-fused silica composites.