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研究了不同直径和含量多壁碳纳米管填充环氧有机硅树脂吸波涂层在2～18GHz频率范围内的介电和吸波性能.可以得到吸波涂层的介电常数随着碳纳米管含量的增加而增大.当碳纳米管含量相同时,吸波涂层介电常数随着碳纳米管直径的增加而增大.当碳纳米管含量大于5wt%时,吸波涂层的介电常数在低频急剧增加,且随频率增大而减少,出现频散效应.反射率测试结果表明:当涂层中多壁碳纳米管含量为10wt%、厚度为2mm时,吸波涂层的最大吸收峰随碳纳米管直径的增大向低频移动.多壁碳纳米管填充环氧有机硅树脂吸波涂层的吸波性能在7～14GHz范围内可达到-10dB,具有较好的吸波效果.

Multi-walled carbon nanotubes as dielectric absorber and epoxy-silicone resin as matrix were used to fabricate multi-walled carbon nanotubes/epoxy-silicone resin coatings. The effects of multi-walled carbon nano-tubes content and diameter on dielectric and microwave absorbing properties of the coatings were investigated in the frequency range from 2GHz to 18GHz. The results indicate that both of the real and imaginary part of the per-mittivity are enhanced with increasing multi-walled carbon nanotubes content and diameter. When the multi-walled carbon nanotubes content is 2wt% , the complex permittivity of the coatings keep almost constant in the frequency range from 2CHz to 18GHz, and are independent on the multi-walled carbon nanotubes diameter. As the multi-walled carbon nanotubes content increases to 5wt% , the complex permittivity of the coatings decreases with the increase of frequency, and also exhibits visible frequency-dependence dielectric response. The minimum reflection loss of the coatings shifts to the low frequency region (from 12.8GHz to 10. 8GHz) as the multi-walled carbon nanotubes diameter increasing. The results of the microwave absorbing properties show that the good nucrowave absorption ability (below - 10dB) can be obtained in a frequency range from 7GHz to 14GHz when the multi-walled carbon nanotubes content is 10wt% and the coating thickness is 2mm.