Synthesis Of High-quality Graphene And Its Hydrophobicity On Stainless Steel Surface

Graphene is a honeycomb planar film formed by carbon atoms in a sp~2 hybrid manner,and has attracted extensive attention due to its extraordinary physical and chemical properties.At present,the most commonly used method for synthesizing graphene is Chemical Vapor Deposition.Through the continuous optimization of experimental parameters,the quality of graphene has been continuously improved.However there are still few studies on the microscopic mechanism of graphene growth.The application of graphene is mainly concentrated in the field of optoelectronics,but when graphene is applied as a thin film coating on stainless steel surface,its surface properties are particularly important.Wettability is one of the most important surface properties of graphene and has an important influence on the corrosion protection of stainless steel.Firstly,an initial model for the deposition of graphene on Cu(111)was established.The microscopic growth process of graphene on the Cu(111)surface was simulated by molecular dynamics.Besides,the influence of temperature on the quality of graphene was studied as well as carbon deposition rate.The results show that carbon atoms underwent three states of carbon dimers and trimers,chains and rings on Cu(111)surface,and there are energy barriers between each state.The effect of temperature on graphene is mainly reflected in the defects of graphene and surface roughness.And carbon deposition rate affects the defects of the graphene surface by changing the nucleation density of graphene.Secondly,based on the wetting theory,two wetting equations of water droplets under the groove microstructure were established,and the wettability of graphene was studied by molecular dynamics simulation.The conclusion that graphene has weak hydrophobicity was obtained.After establishing the wetting model of stainless steel and graphene,the hydrophobicity of graphene was studied.In addition,the effect of groove microstructure in stainless steel surface on the hydrophobicity of graphene was analyzed from the perspective of interaction energy.The results showed that the size of the groove microstructure could change the interaction energy between the substrate and water,thus affecting the hydrophobicity of graphene on stainless steel surface.Finally,an experiment on the hydrophobicity of graphene on stainless steel surface was carried out.Graphene was synthesized by Chemical Vapor Deposition to study the effect of the thickness of the copper foil on the quality of graphene.By the means of the"PMMA"assisted transfer method,graphene was transferred to the surface of stainless steel surface,and the effect of the curing temperature of PMMA on the transfer access of graphene was studied.A nanosecond laser is used to machine the groove microstructure on the stainless steel surface.Groove microstructures of different depths,widths,and pitches are processed by nanosecond laser.After transferring graphene to the surface of the processed groove microstructures,and contact angles of surfaces were measured to reveal the influence of the groove parameters on the hydrophobicity of graphene.