Preparation And Characterization Of Graphene Oxide And Its Two Functional Materials

Graphene,the new type of two-dimensional nanomaterial,relying on its unique structure and excellent physical and chemical properties,has gotten rapid development in recent years.It also has a very broad application prospects,especially in composite materials,electronics,biochemistries,physics and other fields.However,the strong van der Waals force between two graphene layers and its own chemical inertness greatly limits the preparation of graphene in high quality of lattice in large-scale as well as the application of its research,which has become a huge obstacle for the graphene to output performance and benefit mankind.Therefore,the most important direction is to prepare high-quality graphene or graphene functional materials that can remarkably improve its application scope.Until today,the production scale of graphene hasn't been proportional to its mass yet.Moreover,it remains a huge problem in the scientific community and industries that how to utilize graphene with its best state of lamella structure in materials.In this paper,graphene oxide with high-quality lattice and high oxidation rate has been prepared by an electric field-assisted Hummers method;graphene functional materials like graphene dispersions and graphene aerogels have also been prepared;Besides,their applications in the field of materials,adsorption and conductivity were also studied.we have obtained some good experiment results that are as follows:1.Graphene oxide with high-quality lattice structure and high oxidation rate has been prepared using an electric field-assisted Hummers method.Without affecting Hummers method,the DC power can improve the oxidation process to a great extent.Besides,it also greatly reduces the dosage of oxidants,thereby reducing the residue of ion and the energy loss.The graphene oxide prepared by both the improved and conventional Hummers method are nearly the same in their dispersibility,chemical composition,thickness,and lateral dimensions.2.The dispersion stability of graphene dispersions can be greatly improved by mixing with specific solvents by dealing with the ultrasonic cleaners and homogenizers as well as the addition of dispersants and surface-active agents.Homogenization can effectively reduce the two-dimensional layers;The dispersion dispersant is polyvinyl alcohol(PVA),its long alkyl chain can cover on the surface of graphene sheets by electrostatic adsorption and interacte with organic molecules of the solvent which can greatly improve the interaction between graphene oxide nanoplates and solvents,thereby promoting the uniform and stable dispersion.Graphene dispersions added in lubricating oil and epoxy resin materials could keep stable dispersion and effectively improve their lubricated and thermal properties,respectively.3.Graphene aerogels were prepared by hydrothermal method.The performances of graphene aerogels with different experimental parameters were studied.In addition,we double its specific surface area by adding polymer modifier during the preparation of graphene aerogels.the resulting graphene aerogel had a density of 7.8 mg/cm~3.Moreover,graphene aerogels have a variety of outstanding properties,such as excellent mechanical properties,high electrical conductivity and strong adsorption,etc.