纳米二氧化锰掺杂炭黑复合材料电磁特性的研究

Electromagnetic Characteristics of Carbon Black Doped with Nanometer Manganese Dioxide

基于单一吸收剂无法达到良好的微波吸收效果,利用纳米二氧化锰掺杂炭黑颗粒制备了一种新型的复合吸收剂,并进行TEM形貌表征,介电性能分析以及微波吸收性能的测试。结果表明,炭黑属于电阻型损耗介质,主要呈球形多孔状;二氧化锰属于介电损耗介质,特殊的条形片状结构增加了电磁波在机体内的反射次数和散射截面,高电阻特性有效改善了吸波平板材料的输入波阻抗匹配程度,从而大大改善炭黑的微波吸收性能。

A novel absorbing medium of carbon black doped with nanometer sized manganese dioxide were prepared. The microstructure, dielectric constant （ε＇,ε＂） and microwave absorption property of samples were measured by means of transmission electron microscopy （TEM） , transmission/reflection coaxial method from 2GHz to 18GHz and HP 8720B vector network analyzer （VNA）. The results show that manganese dioxide belongs to dielectric loss medium with flake and strip shaped while carbon black belongs to erratic current loss medium with sphere and multi-hole shaped. It is notable that manganese dioxide has a great effort to intensify microwave absorption capability of carbon black due to not only its flake and strip shaped microstructure which can increase the reflection and scatter cross section of electromagnetic wave but also its high resistance which can improve the impedance matching of samples.