不同结构碳纳米管的电磁波吸收性能研究

Complex Permittivity and Permeability Spectra of Different Kinds of Carbon Nanotubes

研究了单壁、多壁碳纳米管(聚团状、阵列状)以及未纯化与纯化后碳纳米管在2～18GHz范围内的电磁波吸收性能.通过测定不同结构碳纳米管粉体的介电常数以及磁导率,得到损耗因子及衰减常数大小顺序为:阵列状多壁碳纳米管>原生聚团状多壁碳纳米管>纯化聚团状多壁碳纳米管>原生单壁碳纳米管>纯化后单壁碳纳米管.相比多壁碳纳米管,单壁碳纳米管衰减常数随频率变化较小,且具有较宽的吸收峰.模拟计算和实验测试结果都表明,碳纳米管/聚合物复合材料具有优良的电磁吸波性能.

Carbon nanotubes （CNTs）, with well defined one-dimension nanoscale tubular structure, have potential applications for electromagnetic wave absorption. The complex permittivity and permeability spectra of different kinds of CNTs were measured in the range from 2 GHz to 18 GHz. The coefficient of attenuation, impedance and loss tangents of different kinds of carbon nanotube composites were compared. The order of loss tangents is as follows： aligned multi-walled CNTs 〉 raw tangled multi-walled CNTs 〉 purified tangled multi-walled CNTs 〉 raw tangled single-walled CNTs 〉 purified tangled single-walled CNTs. The reflectivities of different kinds of carbon nanotube composites were calculated. Compared with multi-walled CNTs, single-walled CNTs have wider absorption capability. Both experimental and calculated results indicated that CNTs as filler in nano-composite materials have excellent elctromagenetic wave absorption properties.