Preparation Of Functionalized Graphene By Wet Ball Milling And Study On Its Properties

The rapid development of the electrical age has driven the development of new materials.Meanwhile,new requirements for the new materialsareput forward.Graphene,known as the"king of new materials",has attracted much attention and expectation due toits excellent characteristics of optics,electricity,and thermodynamics.However,graphene is prone to aggregate and not disperses well in various substrates,which need to be modified.The preparation and functional modification of graphene areusuallycarried out step by step.The development of functionalized graphene preparation strategies with economical,simple,and scalable advantages is of great significance for the development of graphene applied value.Therefore,in this paper,starting from natural flake graphite,the preparation and modification of graphene was conducted to found a new way to improve the dispersion of graphene.The main research contents are as follows:Wetball milling of natural flake graphite with concentrated sulfuric acid was carried out.Concentrated sulfuric acid played the role of oxidation and intercalation during the exfoliation of graphite.This strategy can prepare graphene and improve the dispersion of graphene in water and most polar organic solvents.Since graphite has a complete?-conjugated structure,it exhibits excellent chemical inertness,the oxygen content and apparent color of low-oxide grapheneobtained fromwet ball milling was similar to graphite,indicating that low-oxide graphene has a low degree of oxidation and its structure and properties remain intact.Diels-Alder reaction possesses the characteristics of mild reaction conditions and thermal reversibility,which could combine with the high efficiency of wet ball milling to achieve exfoliation and functionalization of graphite simultaneously.The functionalized graphene?G-MA?showed excellent dispersion in water and polar solvents.Thus,G-MA coating was prepared without binder andsurfactant.The G-MA coating showed a conductivity of 769 S·m^-11 at room temperature,and a big increase could be found at 2000 S·m^-11 after thermal treatment under 200?for 2h,indicating that the?conjugated structurecould partial restored via the reverseDiels-Alder reaction.This strategy of functionalized graphene provides a new way for the reversible modification of graphene,and expands the application of graphene in the electronic device.Finally,using G-MA as conductive filler,a composite conductive ink?G-MA-ink?with excellent dispersion was prepared.The technology of pneumatic spraying could achieve the uniform coating of G-MA-ink on glass,cardboard and plastic films.SEM?Scanning Electron Microscope?imagesof the coating showed the smooth surface and compact structure.Effect of heat treatment temperature on the conductive properties of composite conductive coating was studied.The results showed that the sheet resistance of the composite conductive coating decreased from19 K?·squ^-1?room temperature?to 70?·squ^-1?300??,the conductivity of the coatingwas significantly improved.Based on the excellent dispersion and conductivity of the G-MA-ink,it is expected to exert the advantages ofG-MA-ink in plastic plating,anticorrosive coating,thermal-conductivity material,and so on.