Effects of Multi-walled Carbon Nanotubes on the Electromagnetic Absorbing Characteristics of Composites Filled with Carbonyl Iron Particles  

作　　者：Yonggang Xu Deyuan Zhang Jun Cai Liming Yuan Wenqiang Zhang 

机构地区：[1]Bionic and Micro/Nano/Bio Manufacturing Technology Research Center,School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China

出　　处：《Journal of Materials Science & Technology》2012年第1期34-40,共7页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 50805005);the National "863" Project of China (Grant No. 2009AA043804);the Foundation for the Author of National Excellent Doctoral Dissertation of PR China (Grant No. 2007B32)

摘　　要：The electromagnetic （EM） wave absorbing property of silicone rubber filled with carbonyl iron particles （CIPs） and multi-walled carbon nanotubes （MWCNTs） was examined. Absorbents including MWCNTs and spherical/ flaky CIPs were added to silicone rubber using a two-roll mixer. The complex permittivity and complex permeability were measured over the frequency range of 1-18 GHz. The two EM parameters were verified and the uniform dispersion of MWCNTs and ClPs was confirmed by comparing the measured reflection loss （RL） with the calculated one. As the MWCNT weight percent increased, the RL of the spherical CIPs/silicone rubber composites changed insignificantly. It was attributed to the random distribution of spherical ClPs and less content of MWCNTs. On the contrary, for composites filled with flaky ClPs the absorption bandwidth increased at thickness 0.5 mm （RL value lower than -5 dB in 8-18 GHz） and the absorption ratio increased at lower frequency （minimum -35 dB at 3.5 GHz）. This effect was attributed to the oriented distribution of flaky CIPs caused by interactions between the two absorbents. Therefore, mixing MWCNTs and flaky CIPs could achieve wider-band and higher-absorption ratio absorbing materials.The electromagnetic （EM） wave absorbing property of silicone rubber filled with carbonyl iron particles （CIPs） and multi-walled carbon nanotubes （MWCNTs） was examined. Absorbents including MWCNTs and spherical/ flaky CIPs were added to silicone rubber using a two-roll mixer. The complex permittivity and complex permeability were measured over the frequency range of 1-18 GHz. The two EM parameters were verified and the uniform dispersion of MWCNTs and ClPs was confirmed by comparing the measured reflection loss （RL） with the calculated one. As the MWCNT weight percent increased, the RL of the spherical CIPs/silicone rubber composites changed insignificantly. It was attributed to the random distribution of spherical ClPs and less content of MWCNTs. On the contrary, for composites filled with flaky ClPs the absorption bandwidth increased at thickness 0.5 mm （RL value lower than -5 dB in 8-18 GHz） and the absorption ratio increased at lower frequency （minimum -35 dB at 3.5 GHz）. This effect was attributed to the oriented distribution of flaky CIPs caused by interactions between the two absorbents. Therefore, mixing MWCNTs and flaky CIPs could achieve wider-band and higher-absorption ratio absorbing materials.

关 键 词：Absorbing materials Carbon nanotubes Carbonyl iron particles COMPOSITES Reflection loss 

分 类 号：TN04[电子电信—物理电子学] TB383[一般工业技术—材料科学与工程]