Electromagnetic Properties Of Graphene/ferrite/carbon Fiber Composites

With the rapid development of information technology,electronic products are widely used in daily life.The application of electromagnetic wave has brought great convenience,also caused serious electromagnetic pollution.It will not only cause harm to human body,but lead to more electronic equipment system damage.Therefore,the development of lightweight and efficient electromagnetic shielding materials is an effective way to solve the problem of electromagnetic pollution.In this paper,graphene oxide?GO?,carbon fiber?CF?and nano Fe₃O₄ were used to prepare electromagnetic shielding composite material.The microstructure characterization and the performance were tested by SEM,TEM and FTIR.Then the mechanism of electromagnetic shielding was analyzed.The concrete research content are as follows:?1?Nano Fe₃O₄ was prepared via solvent thermal method and its morphology.The structure and the magnetism were characterized.The surface treatment of CF was conducted by electrochemical etching.CF/Fe₃O₄/cement composites were prepared by CF and nano Fe₃O₄ as the substrate.The electromagnetic shielding performance was tested in the X-band?8.2¹2.4 GHz?.Test results showed that when CF content was 0.4 wt%and nano Fe₃O₄content was 5 wt%,the electromagnetic shielding effectiveness value of CF/Fe₃O₄/cement composites samples reached 29.8 dB in 12.4 GHz,which increased by 34.4%compared with the pure CF/cement composites.?2?The GO solution was prepared by improved Hummers method and characterized by SEM and TEM,which proved that GO was the laminar structure of the surface fold.GO film was used as surface.CF,nano Fe₃O₄ were used intercalation and PVA was used adhesives to prepare three-dimensional structure of film.The experimental results showed that,with the the increase of ratio and content of CF and nano Fe₃O₄,thin film layers,the electromagnetic shielding performance of films increased gradually.When the ratio of CF and nano Fe₃O₄ was6:5,the electromagnetic shielding effectiveness of single layer composites reached 20.6 dB in12.4 GHz,and double-layer structure composites reached 29.6 dB,increased by 43.7%.?3?As raw material,biomass corn straw was crushed and surface activation treatment,then mixed with GO solution to prepare GO-straw.The samples after freezed drying were treated under high heat for 1 h,rGO/AC hybrid materials were prepared.The test results showed that the straw had porous structure,which improved the structural stability of rGO.The best heat treatment temperature was 600?.The nano Fe₃O₄ and the hybrid material created synergy,which improved the effect of composites of electromagnetic wave shielding.When the content ratio of rGO/AC and nano Fe₃O₄ was 1:1,the electromagnetic shielding effectiveness of the composites was 18.6 dB.