Improved Performance Of Graphene Membranes When Combined With Fibrous Materials

With the increase in the power density of electronic components,the heat dissipation problem has become an important factor restricting the improvement of the integration degree of electronic equipment.The performance of heat dissipation device is closely related to materials.Therefore,the development of new heat dissipation materials is a breakthrough to improve the performance of relevant devices.Graphene has a wide range of applications in the field of heat transfer due to its unique structure,which gives it ultra-high thermal conductivity.The preparation of graphene heat dissipation membrane by carbonization and graphitization of polyimide membrane is the main application method in the field of heat transfer.But there are also disadvantages exist such as complex preparation process,high cost and huge energy consumption.In contrast,there is a feasible way to make graphene heat dissipation composite membranes instead of graphitization to maximize the thermal conductivity advantage of graphene through ingenious material structure design.Therefore,in this paper,GO membrane was prepared by the extraction of graphene oxide(GO)dispersion,and the preparation of reduced GO(rGO)membrane was under 800? thermal reduction,and we added magnetic carbon fiber(MCF)and chopped glass fiber(GF),the structure of rGO membrane was changed to improve thermal conductivity,which is applied in a new idea for the preparation of graphene heat dissipation composite membrane.We got good quality GO dispersion by adjusting a modified Hummers' method.The GO membrane was prepared by extraction and filtration method and the rGO membrane was obtained under 800 ? thermal reduction.By analyzing the rGO membrane of different thickness and its thermal conductivity,we found that the heat conduction model of the rGO membrane prepared by extraction and filtration method was obtained on the basis of Klemens' heat conduction model.The carboxylate polyacrylonitrile carbon fiber was used to prepare MCF by coprecipitation method.The paralleled MCF skeleton was constructed in the GO membrane by external magnetic field guidance,and the MCF-rGO composite membrane was obtained by thermal reduction.Through a variety of characterization analysis,it could be concluded that the addition of paralleled MCF skeleton reduced the number of rGO stacking layers and increased the interval between layers of rGO slices,thus we could effectively reduce the interlayer phonon scattering of rGO and improve the thermal conductivity of the composite membranes.The thermal conductivity model of MCF-rGO composite membrane was prepared by extraction and filtration method was obtained.GF skeleton was constructed in GO membrane and GF-rGO composite membrane was obtained under 800? thermal reduction.Modified rGO was obtained by HF corrosion of GF.The addition of GF skeleton reduced the number of stacking layers of rGO in the GF-rGO composite membrane.When GF was corroded away,the gap in the modified rGO still maintained.The thermal conductivity model of the modified rGO membrane could be fitted.Combined with the heat conduction model of the modified rGO membrane.It could be concluded that the essence of improved thermal conductivity of rGO membrane by fibrous material was to construct a structure that reduced the stacking of rGO layers.With the increase of the fibrous material,the thermal conductivity of the rGO membrane had an obvious trend of increasing first and then decreasing.When the separation effect of the fibrous material on the rGO membrane was up to the highest point,rGO could exert its maximum thermal conductivity.