Study On The Mechanism Of Interfacial Nanobubbles And Graphene Properties

The interface is the phase interface,which refers to the interface between different phases,such as gas phase,liquid phase and solid phase.In daily life,many places are inseparable from the interface.Interfacial nanobubbles,a kind of bubble that is very conceemed about at the microscopic scale,has been found relatively late,so its properties and research are not perfect,and its application has not been fully developed.Graphene is one of the most interesting materials of this century,so it is important to study its properties.People mainly study the properties of graphene as a material,such as its conductivity,hardness,optical properties,etc.,but little attention is paid to the diffusion or movement of droplets on graphene.At the microscopic scale,the flow of droplets over graphene in confined spaces has not yet been explored.In this paper,the effect of interfacial nanobubbles on liquid boiling nucleation was studied theoretically,and the molecular dynamics simulation method was used to study the flow of NaCl droplets on graphene surface,and the factors affecting the flow were further explored.Specific research results include the following:1.Study the effect of interfacial nanobubbles on liquid boiling nucleation.Through theoretical analysis,we infer that the surface heterogeneity of nano-sized surface nanobubbles can promote the transition from liquid phase to gas phase,and obtain three mechanisms that can reduce liquid boiling into a nuclear barrier:nucleation caused by anchored nanobubbles;Nucleation caused by nanobubble depinning;Nucleation caused by the aggregation of nanobubbles;Compared with the crack model,it can be seen that both of them are oriented nucleation growth determined by the metastability of surface nanobubbles and surface geometry.These results are expected to be helpful for the study of gas-liquid phase transition and interfacial nanobubbles in the future.2.Molecular dynamics simulation of the flow of NaCl droplets on graphene surface was studied.We first found that NaCl solution on the hard graphene surface would approach the graphene surface close to it and move on it periodically.On the surface of soft graphene,NaCl solution will move to one comer of graphene and stay there.NaCl solution will be wrapped in the upper and lower layers and form a state similar to "dumpling shape".Cu was used to fix the graphene in the lower layer,and it was found that the graphene in the upper layer still covered NaCl solution,NaCl solution still move towards the angle.By changing the shape,size and number of droplets on the top of the graphene,we get basically the same result.Through our simulation,we hope to have a further understanding of the movement of ionic solution on the surface of graphene and provide some useful help for the development of potential applications of graphene in the future.