Preparaion And Properties Study On Carbon Fiber Paper-based Shielding Materials

With rapid development of information technology and electronic technology,there are many electrical equipments in people's life,people's work efficiency and quality of life are remarkable improved by using different electrical equipment.While it could produce electromagnetic radiation,which has inconvenienced to people's life and threat to human health,Therefore,it is significant to fabricate high-performance shielding materials.Graphene benefits a unique structure,superior conductivity.It is one of the most promising electromagnetic shielding materials.At the same time,nickel is also a kind of material with high permeability,which can produce great absorption loss to electromagnetic wave.It is a kind of shielding material with great potential for development.The graphene/carbon fiber electromagnetic shielding paper and plant fiber electroless nickel/carbon fiber electromagnetic shielding paper were prepared using vacuum pumping method in this study,carbon fiber and plant fiber were used as the skeleton materials,the conductivity and electromagnetic shielding performance have been study systematically,which could provide a theoretical basis for the preparation of high performance electromagnetic shielding products.First,the carbon fiber was modified by oxidation to increase the number of active groups on the surface.The dispersion of plant fiber after electroless nickel plating,carbon fiber and the dispersibility of the mixed system of graphene,plant fiber,carbon fiber were studied respectively.It was found that the viscosity of the mixture decreases first and then increases,With the increase of the amount of reducing agent dimethylaminoborane(DMAB),It was found when the amount of dimethylsulfaborane(DMAB)is 3g/L,there is the lowest viscosity,the best dispersion in the mixture,Besides,the coating rate is also larger.The effects on the dispersibility of the mixture of graphene,plant fiber and carbon fiber pulp were studied,it was found that when the plant fiber and carbon fiber slurry mixture dispersed with a rotation speed of 20000 r/min,ultrasonic time at 22.5min and CPAM dosage of 0.5%,the mixture of graphene,plant fiber and carbon fiber had the best dispersion.Secondly,the graphene was added into the paper-based material by vacuum filtration to prepare the graphene/carbon fiber paper-based shielding material,the effects of the addition of graphene on the conductivity and shielding properties of carbon fiber paper-based materials have also been studied.The graphene/carbon fiber paper-based materials were prepared under the best experimental condition,and the surface morphology,mechanical properties,electrical conductivity and electromagnetic shielding properties of graphene/ carbon fiber paper-based materials were characterized by scanning electron microscopy,tensile strength tester,four-probe resistivity tester and vector network analyzer respectively.Moreover.The effect of graphene addition on graphene paper-based materials was also investigated.The resistivity of graphene/carbon fiber paper was reduced to a minimum of 0.662? · cm.At the same time,it has the highest electromagnetic shielding effect with 10wt% graphene.In addition,electroless nickel was plated on the surface of the plant fiber by electroless plating,and electroless nickel-coated carbon fiber paper-based materials was prepared by vacuum suction filter method,The effects of nickel coating on the mechanical properties,electrical conductivity and shielding properties of paper-based materials were studied.The nickel-coated carbon fiber paper and graphene/carbon fiber paper-based materials were compared and analyzed.Two Carbon fiber paper-based materials were compared.The results were as follows:electroless nickel-coated carbon fiber paper-based materials in the mechanical properties and conductivity performance were relatively large differences.There is no much more difference in electromagnetic shielding performance compared with graphene/carbon fiber paper-based material.The value of both were not exceed 2d B when the frequency was the same.In summary,according to the comparison results of the graphene/carbon fiber paper and electroless nickel-carbon fiber paper,graphene/carbon fiber paper was more suitable for electromagnetic shielding,which could better shield the electromagnetic waves.