Preparation Of Wave-absorbing Micro/Nano Composite

With the development of modern technology science, absorbing-wave materialhave the great potential applicating in the field of stealth technology andelectromagnetism shielding. The research of absorbing material is mainly focused onabosrobing-wave nanopowder and doping or composite. The main research content is asfollows:In this thesis, the graphene oxide loaded ferrite composite was prepared by thehydrothermal method to improve their electromagnetic properties. First of all, grapheneoxide was prepared from graphite powder which was oxidized by strong oxidant andthen treated at high temperature as raw material. Secondly, The oxidation graphene/manganese zinc ferrite composite was successfully prepared by hydrothermal methodusing Fe（NO3）2、MnCl2、Zn（NO3）2and graphene oxide as raw material, sodiumhydroxide as precipitating agent. The effect of process parameters such as ratio ofgrapheme to ferrite, pH value, reaction time, reaction temperature on the morphologyand structure of composite were carried out in detail. Finally, carbon black/cobalt zincferrite composite was prepared by hydrothermal method with the ethanol as solute. Theoptimum process parameters were obtained by the studying of the effect of processparameters such as ratio of grapheme to ferrite, pH value, reaction time, reactiontemperature on the morphology and structure of composite, which was characterizedwith XRD, SEM and IR spectrum. Furthermore, the magnetism and electromagnismproperty of composite was carried out in detail. The results showed that the key factorsis ratio and pH value for the morphology and tructure of composte. The manganese zincferrite was uniformly distributed on graphene oxide with nanometers size. Theoptimized ratio is2:1to form ideal carbon black loaded CoZn ferrite. The higher pHvalue and longer reaction time, the smaller the size distribution of ferrite. The magnetic and electromagnetism property analysis showed the two kinds of composite are idealwave-absorbing materials due to the higher electrical and magnetism loss and the lowercoercive force.