Microwave Absorption And Infrared Radiation Properties Of Al@Manganese Dioxide(Reduced Graphene Oxide/Mutli-walled Carbon Nanotubes Composites)

Flake Al powder has a low infrared emissivity,manganese dioxide?MnO₂?is a semiconductor microwave absorption material,reduced graphene oxide?RGO?and multi-walled carbon nanotubes?MWCNTs?are conductive microwave absorption materials.The composites compound by the above materials can effectively improve the impedance matching,increase the microwave absorption performance,and at the same time have low infrared radiation.Al@MnO₂,Al@RGO and Al@MWCNTs composites were prepared.The materials were characterized and analyzed by X-ray diffraction?XRD?,X-ray photoelectron spectroscopy?XPS?,scanning electron microscope?SEM?,transmission electron microscope?TEM?,vector network analyzer?VNA?and IR-2 dual-band emissivity tester?IREM?.The specific results are as follows:?1?Using potassium permanganate?KMnO₄?and flake Al powder as raw materials,Al@MnO₂ composites were prepared by one-step chemical reaction.The effects of the mass ratio of KMnO₄ to Al on the morphology,electromagnetic parameters,microwave absorption performance and infrared emissivity of Al@MnO₂composites were studied.The results showed that with the increase of the mass ratio of KMnO₄ in the composite,the density of MnO₂ nanoparticles on the surface of Al sheet increased,the microwave absorption performance first increased and then decreased,and the infrared emissivity gradually increased.When the mass ratio of KMnO₄:Al is2:5,the minimum reflection loss value of Al@MnO₂ composite is-42.93 dB at 12.72GHz,the effective absorption bandwidth below-10 dB is 1.28 GHz?12.08-13.36 GHz?,the matching thickness is 1 mm,and its infrared emissivity is 0.59.?2?Using Graphite oxide?GO?and flake Al powder as raw materials,Al@RGO composites were prepared by one-step hydrothermal method.The effects of the mass ratio of GO to Al on the morphology,electromagnetic parameters,microwave absorption performance and infrared emissivity of Al@RGO composites were discussed.The results showed that with the increase of GO's mass ratio in the composite,the content and folds of RGO on the surface of Al increased,the microwave absorption performance became stronger,and the infrared emissivity gradually increased.When the mass ratio of GO:Al is 1:1,the minimum reflection loss value of Al@RGO composite is-46.11 dB at 13.68 GHz,and the effective absorption bandwidth lower than-10 dB is 4.88 GHz?11.52-16.4 GHz?,the matching thickness is2 mm,and the infrared emissivity is 0.69.?3?Using acidified MWCNTs and flake Al powder as raw materials,Al@MWCNTs composites were prepared by one-step hydrothermal method.The effects of the mass ratio of MWCNTs to Al on the morphology,electromagnetic parameters,microwave absorption performance and infrared emissivity of Al@MWCNTs composites were analyzed.The results showed that with the increase of MWCNTs'mass ratio in the composite,the density of MWCNTs between Al plates increased,the microwave absorption performance changed from poor to strong,and the infrared emissivity gradually increased.When the mass ratio of MWCNTs:Al reaches 3:20,the minimum reflection loss value of Al@MWCNTs composite at 10.88GHz is-39.24 dB,the effective absorption bandwidth below-10 dB is 3.04 GHz?9.2-12.24 GHz?,the matching thickness is 2 mm,and the infrared emissivity is 0.67.Figures[21]Tables[7]References[109]...