Preparation And Absorbing Property Study Of MWCNT/Fe₃O₄/PANI/Au Hetero Structure Compound

Absorbing materials has been widely used in stealth technology,energy-savingtechnology and civilian radiation protection field, especially in military stealth field.With the rapid development of electronic technology, weapons on the battlefield areunder severe threat.In modern warfare, acquisition,reconnaissance and capture targethas become the focus of the war. At present,only radar band or infrared wavelengthsabsorbing materials has good absorbing performance. Broadband absorbing materialsthat can can widely used is still uncomplete, the traditional broadband absorbingmaterials were made by layered coating method, the preparation process is complicatedand binding force between the layers is poor. In this study, we prepared carbonnanotubes based quaternary composite materials, the four components play their rolerespectively and coupled together either, show a good wave absorbing performance.Theprepared material is a visible light, infrared and microwave multi-frequency integrationabsorption materials. And solved the problem of poor binding force between layers ofprevious multi-frequency absorbing material.In this study, we prepared MWCNT/Fe₃O₄/PANI/Au quaternary heterostructurecompound, dielectric loss absorbing material MWCNT as the inner components canensure the mechanics performance of the material; magnetite （Fe₃O₄） nanocrystalsgrown on multiwalled carbon nanotube （MWCNT）, the dielectric and magneticcoupling enhanced the absorbing performance; Time outer is dielectric loss absorbingmaterials polyaniline, solved the problem of poor binding force between absorbingmaterials and binder; The outermost layer of gold nanoparticles, has three ordernonlinear and plasma effect, has absorption in visible light wave band. The fourcomponents play their role respectively and coupled together, absorbing performance isincreased.First of all, we studied the preparation process conditions of PANI coated onMWCNT/Fe₃O₄compound, observe the morphology through TEM, ultimately no aciddoping method is used to synthesis PANI, The system acidity controled within5⁶,the optimization of the reaction temperature is0℃through observe the morphologythrough by SEM. Study whether the amount of PANI coated is controllable. ThroughTEM and SEM method, the optimization thickness of PANI coating is20nm. When thecontent of MWCNT/Fe₃O₄/PANI is50wt%, minimum reflection loss of-22dB（≈98% of EM wave absorption） at14.6GHz and an effective absorption band（RL<-10dB）covering a frequency range of2.5¹8GHz with a thickness of0.9⁵mm.We studied the preparation process conditions of Au nanoparticles coated onMWCNT/Fe₃O₄/PANI compound, Observe the morphology through TEM, ultimatelyuse oxidation-reduction method, reducing agent is aniline. Through morphologyobservation and performance analysis, use PVP as surface coating agent. Study whetherthe amount of Au nanoparticles coated is controllable.The optimization thickness of Aunanoparticles coating is mass ratio of MWCNT/Fe₃O₄/PANI：HAuCl4=1:2.When thecontent of MWCNT/Fe₃O₄/PANI/Au is50wt%, minimum reflection loss of-60dB（≈100%of EM wave absorption）at9GHz and an effective absorption band（RL<-10dB） covering a frequency range of8¹1GHz with a thickness of2.2mm.