Preparation And Application Study Of Modified Graphene

As a typical two-dimensional carbon material,graphene has excellent performance in light,electricity,mechanics,etc.,and has broad application prospects in many fields.However,the surface of graphene is relatively inert,has low compatibility with other media,and is easy to agglomerate,which limits its application in real life.At present,in order to solve the problem of graphene stacking,more ideas are applied to modify its surface.This paper studies the preparation of graphene by ball milling and doping modification of graphene with nitrogen and fluorine atoms.It is expected to improve the dispersibility of graphene in solvents(water,anhydrous ethanol,etc.),and at the same time to modify the graphene Make an application attempt.The main research contents include:1.Graphene was prepared by using natural graphite balls as raw materials and mechanically stripped by ball milling.The effects of ammonium carbonate and hydrazine hydrate as additives on the stripping and modification of graphene were studied.The results show that the presence of ammonium carbonate and hydrazine hydrate can dope nitrogen on the surface of graphene,but the ball milling time,ball milling frequency,and ball-to-material ratio have effects on the stripping effect of nitrogen and the effect of nitrogen doping.After comprehensive optimization,when the ball milling frequency is 200 rpm,the ball milling time is 20 hours,and the ball-to-material ratio is 100:1,the quality of the modified graphene obtained is the best.The graphene at this time has a thin layer structure,and the nitrogen content on the graphene surface is 5.89 %.This product has good dispersibility and stability in water,absolute ethanol and nitrogen nitrogen dimethylpyrrolidone solvent.Using this product for tin-nickel alloy coating,a Sn-Ni / graphene composite coating was successfully prepared.Through the distribution test of graphene in the coating,it was found that graphene can be evenly distributed in the coating.The addition of graphene can refine the grains and improve the corrosion resistance of the coating.The corrosion resistance test results of the composite coating show that the composite coating has the best corrosion resistance when the concentration of graphene is 300 mg · L-1.2.Graphene was prepared by using fluorinated graphite as a raw material and mechanically stripped by a ball milling method.The effects of the types of additives(ammonium carbonate,NMP)on the structure and properties of graphene were studied.The results show that the presence of ammonium carbonate and NMP can produce nitrogen and fluorine doped graphene.When the ball milling frequency is 200 rpm,the ball milling time is20 hours,and the ball-to-material ratio is 100:1,the quality of the modified graphene obtained is the best.The graphene has a nitrogen content of about 10.46 % and a fluorine content of about 22.70 %.The presence of nitrogen and fluorine enhanced the dispersibility of graphene in water,absolute ethanol and NMP.In this paper,nitrogen-fluorine co-doped graphene was tried as a lubricant additive.The research results show that nitrogen and fluorine-doped graphene can be uniformly dispersed in the lubricating oil and has good stability.The addition of nitrogen and fluorine-doped graphene has significantly improved the friction and wear properties of lubricating oils.It is a potential lubricating oil additive and is expected to be applied in the field of lubrication.