Controllable synthesis of mesoporous carbon hollow microsphere twined by CNT for enhanced microwave absorption performance
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第24期
论文作者：Minghang Li Xiaomeng Fan Hailong Xu Fang Ye Jimei Xue Xiaoqiang Li Laifei Cheng
摘 要：The low dielectric loss of mesoporous carbon hollow microsphere（PCHM） requires high filler loading（higher than 20 wt%） when it is used as microwave absorbers. In order to decrease the filler loading of PCHM, a new strategy for synergistic increase of polarization and conductive loss was developed by twining PCHM with carbon nanotube（CNT） according to theoretic calculation. By the optimization of CNT content, the minimum reflection coefficient was-34.6 d B with a filler loading of only 10 wt%,which was much lower than-2.1 d B of PCHM. In addition, the effective absorption bandwidth was 3.6 GHz at X band with a thickness of 2.8 mm. The enhanced microwave absorption performance can be ascribed to the unique combination of hollow PCHM and one-dimensional CNT with higher graphitization degree, leading to increase of conductivity and heterogeneous interfaces. As a result, the conductive loss increased from 0.12 to 2.27 and polarization loss increased from 0.15 to 0.67, achieving the balance between attenuation ability and impedance match.
Minghang Li，Xiaomeng Fan，Hailong Xu，Fang Ye，Jimei Xue，Xiaoqiang Li，Laifei Cheng
Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University
摘 要：The low dielectric loss of mesoporous carbon hollow microsphere（PCHM） requires high filler loading（higher than 20 wt%） when it is used as microwave absorbers. In order to decrease the filler loading of PCHM, a new strategy for synergistic increase of polarization and conductive loss was developed by twining PCHM with carbon nanotube（CNT） according to theoretic calculation. By the optimization of CNT content, the minimum reflection coefficient was-34.6 d B with a filler loading of only 10 wt%,which was much lower than-2.1 d B of PCHM. In addition, the effective absorption bandwidth was 3.6 GHz at X band with a thickness of 2.8 mm. The enhanced microwave absorption performance can be ascribed to the unique combination of hollow PCHM and one-dimensional CNT with higher graphitization degree, leading to increase of conductivity and heterogeneous interfaces. As a result, the conductive loss increased from 0.12 to 2.27 and polarization loss increased from 0.15 to 0.67, achieving the balance between attenuation ability and impedance match.
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