碳纳米管/平面各向异性羰基铁复合材料的液相共混法制备及其电磁性能

采用机械球磨法制备了平面各向异性羰基铁（Planar Anisotropic Carbonyl Iron，PACI），然后通过液相共混法制备了碳纳米管（CNTs）/PACI复合材料。采用同轴法测定CNTs/PACI复合材料在2~18 GHz频段内的复介电常数和复磁导率，研究了CNTs掺杂量对复合材料电磁性能的影响。结果表明：CNTs/PACI复合材料相对于PACI具有更高的复介电常数和衰减常数，随着CNTs质量分数的提高，复合材料的复介电常数和衰减常数逐渐增大，特征阻抗则逐渐减小。CNTs掺杂能够有效提高CNTs/PACI复合材料的吸波性能，通过调整厚度和CNTs掺杂量可以对复合材料的吸波性能进行有效调控。厚度为1.2 mm、CNTs质量分数为2wt%和厚度为1.6 mm、CNTs质量分数为0.5wt%的CNTs/PACI复合材料在Ku波段（12~18 GHz）的反射率均小于-10 dB；厚度为2.0 mm、CNTs质量分数为0.5wt%和1wt%的复合材料反射率小于-10 dB的频带宽分别为5.28 GHz（8.24~13.52 GHz）和5.04 GHz（7.52~12.56 GHz），覆盖整个X波段（8~12 GHz）。

Solution blending preparation and electromagnetic properties of carbon nanotubes/planar anisotropic carbonyl iron composite

The planar anisotropic carbonyl iron (PACI) was firstly fabricated by mechanical ball milling. Then the carbon nanotubes(CNTs)/PACI composite was prepared by solution blending method. The complex permittivity and complex permeability of the samples between 2-18 GHz were measured through coaxial method. The effects of the CNTs doping content on the electromagnetic properties of CNTs/PACI composites were investigated. The results show that the CNTs/PACI composites have higher complex permittivity and attenuation constant compared with PACI.The complex permittivity and attenuation constant of the composites increase gradually with the increasing mass fraction of CNTs (W_CNTs), while the microwave impedance decreases gradually. Doping CNTs can effectively improve the microwave absorption properties of CNTs/PACI composites. Through adjusting the thickness (d) and the CNTs doping content, the microwave absorption properties of the composites can be effectively controlled. When d=1.2 mm and W_CNTs=2wt%, or d=1.6 mm and W_CNTs=0.5wt%, the reflection loss (R_L) of CNTs/PACI composite in Ku band (12-18 GHz) is below -10 dB. When d=2.0 mm, W_CNTs=0.5wt% and 1wt%, the bandwidth corresponding to the R_L of the composites below -10 dB is 5.28 GHz (8.24-13.52 GHz) and 5.04 GHz (7.52-12.56 GHz) respectively, which covering the entire X band (8-12 GHz).