Preparation And Application Of High Quality Graphene

Graphene is a kind of two-dimensional honeycomb crystal structure closely arranged by a honeycomb-shaped sheet of carbon atom,because of its high strength,high light transmittance,high conductivity and other advantages;it has broad application prospects in the fields of sensors,semiconductor devices,transparent conductive film etc.The most commonly used preparation methods of graphene are chemical vapor phase deposition method and oxidation reduction preparation method,the former has difficulties in achieving large-scale industrial production,while graphene prepared by the latter method share many defects,poor performance,and the preparation process would cause environmental pollution as well.In this study,we first explored a method for the preparation of graphene by mechanical shearing in the liquid phase.A certain amount of different types of graphite powder is dissolved into different kind of solvent by using emulsification machine,the effects of the types of graphene and solvents,the shear rate and time on the quality of the graphite powder were systematically investigated,the best shear reagent methyl pyrrolidone(NMP)was deduced from the surface energy model of graphene and liquid phase.According to the shear model and the comparison of the dispersion properties of the graphene samples in different shear parameters,the best shear parameters were obtained:shear rate 10000rpm,shearing time 1-2 hours.SEM,Raman spectroscopy,TEM and other methods were used to test the properties of the sheared graphene.The results showed that this method can be used to control the preparation of low layer graphene and has excellent electrical conductivity.Compared with the two kinds of traditional graphene preparation methods chemical vapor deposition and oxidation reduction,the shear method has the advantages of batch preparation of high quality graphene,and has a far-reaching application and research value in realizing graphene's macro applications.In addition,this study prepared graphene oxide by the improved Hummers method,and used saline coupling agent to modify the surface groups.The modified graphene oxide was used as the filler of epoxy coating and its main corrosion resistance was tested.The main results are as follows:Epoxy resin viscosity test and SEM test show that the modified graphene oxide can be uniformly dispersed in the epoxy resin,and has no effect on its main performance;Using 20000 magnification SEM observation of graphene oxide epoxy coating,the coating structure of it is smooth and complete,confirmed that the graphene oxide added to offset the inherent hole of epoxy coating,which helps to prevent small molecular pollutants directly specimens provide a guarantee;Using modified graphene oxide as the main filler in zinc rich epoxy paint.After curing the effect of coating shows that graphene oxide does not affect the coating properties of epoxy zinc rich paint;resistance to friction test and saline immersion confirmed that graphene oxide-zinc rich epoxy paint coating enhanced abrasion resistance and salt water resistance ability has been significantly improved compared with pure epoxy resin paint;Comparison of different graphene oxide ratio formula of strengthening epoxy paint coating corrosion resistance,confirmed that without affecting the performance of the coating,adding graphene oxide can not only improve the corrosion resistance of the coating,but also reduce the amount of zinc powder to a considerable extent,there are good prospects for control and the application of the coating cost.