Magnetic hollow mesoporous carbon composites with impedance matching for highly effective microwave absorption
Magnetic hollow mesoporous carbon composites with impedance matching for highly effective microwave absorption
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DOI：
10.1007/s10853-018-3100-z
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发表时间：
2018-11
影响因子：
4.5
通讯作者：
Guozhu Shen;Junzhao Ren;Bin Zhao;B. Mei;Hongyan Wu;Xumin Fang;Yewen Xu
中科院分区：
文献类型：
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作者：
Guozhu Shen;Junzhao Ren;Bin Zhao;B. Mei;Hongyan Wu;Xumin Fang;Yewen Xu
采用“聚合-热解-刻蚀”的方法成功地合成了具有大的空气/碳界面和内部空隙的轻质中空介孔碳球（HMCSs）。在2-18 GHz频率范围内，碳化温度可以调节HMCSs的复介电常数，有利于设计不同频率范围的吸波材料。当HC-700/石蜡复合材料中HMCs含量为10wt%、厚度为2.5mm时，在6.7GHz处的最小反射损耗值为-26.4dB，最大有效吸收带宽（小于-10dB）为5.5GHz。为了提高磁损耗和改善HMCSs的阻抗匹配，采用化学镀方法在HMCSs上沉积存款Ni和Fe纳米颗粒。通过综合考虑介电损耗、磁损耗和阻抗特性，加入40 wt% HC-Fe的新型轻质Fe/HMCSs复合材料具有良好的上级微波吸收性能。在所有设计厚度下都能获得较强的反射损耗，在大于1.2 mm的每一个厚度下，反射损耗的峰值小于-20 dB。最小反射损耗在13.0 GHz处达到− 49.7 dB，有效吸收带宽为4.0 GHz，厚度为1.6 mm。该研究为轻质吸波材料的制备和设计提供了新的思路。
Lightweight hollow mesoporous carbon spheres (HMCSs) with large air/carbon interface in the mesoporous shell and interior void have been successfully synthesized via a ‘polymerization–pyrolysis–etching’ route. The complex permittivity of the HMCSs can be easily adjusted by carbonization temperature in the frequency range of 2–18 GHz, which is in favor of designing absorbers in different frequency range. The minimum reflection loss value of − 26.4 dB at 6.7 GHz with a thickness of 5.0 mm and the maximum effective absorption bandwidth (less than − 10 dB) of 5.5 GHz can be gained for the HC-700/paraffin composite with only 10 wt% HMCSs and a thickness of 2.5 mm. To enhance the magnetic loss and improve the impedance matching of the HMCSs, electroless plating methods are employed to deposit Ni and Fe nanoparticles on the HMCSs. Benefiting from the dielectric loss, magnetic loss and impedance characteristic, the new lightweight Fe/HMCSs composite with 40 wt% HC–Fe shows superior microwave absorption properties. The stronger reflection loss can be obtained at all designed thicknesses, and the peak value of reflection loss is less than − 20 dB at each thickness of greater than 1.2 mm. The minimum reflection loss reaches − 49.7 dB at 13.0 GHz, and the effective absorption bandwidth is 4.0 GHz with a thickness of 1.6 mm. This research is providing a new insight in the preparation and design of lightweight microwave absorption materials.