| Monolayer molybdenum disulfide（Mo S2）is a two-dimensional material with excellent mechanical,electrical and optical properties,which has wide application prospects in micro-nano electromechanical systems,semiconductor optoelectronic devices field effect transistors.At the micro-nano scale,the specific surface area of the material will increase,so the wetting characteristics of Mo S2 will have an important impact on its performance.Since mechanical strain will have a greater impact on the wetting characteristics of materials,this thesis adopts molecular dynamics（MD）methods to study the wetting characteristics of monolayer Mo S2 under different strains.The main research contents include:（1）The MD method is used to study the wetting behavior between monolayer Mo S2 and water.Loading uniaxial and biaxial strains along the zigzag and armchair-shaped boundary directions of monolayer Mo S2,and observing the contact angle of water droplets on the surface.The results show that the contact angle of water droplets on monolayer Mo S2 is 77.4°at zero strain.Tensile strain will increase the contact angle of water droplets,while compressive strain will decrease the contact angle of water droplets,and the effect of biaxial strain on the wetting characteristics of Mo S2 More significant.（2）Using MD method,the wetting behavior between monolayer Mo S2 and glycerol is studied,and the effect of strain on the surface energy of monolayer Mo S2 is observed.Loading uniaxial and biaxial strains along the zigzag and armchair-shaped boundary directions of monolayer Mo S2,and observing the contact angle of glycerol droplets on the surface.The results show that the contact angle of glycerol is 69.5°at zero strain.Tensile strain will increase the contact angle of glycerol droplets,that is,tensile will reduce the surface energy of the monolayer Mo S2;while compressive strain will decrease the contact angle of glycerol droplets,that is,compressive will increase the surface energy of the single-layer Mo S2.（3）Using a strain loading experimental device and the contact angle tester,the wetting characteristics of water droplets on the surface of a single layer of Mo S2 under uniaxial tensile strain were studied.The results show that the change trend of the contact angle of water droplets on a monolayer of Mo S2 is the same as the change trend of the contact angle of water droplets obtained by MD simulation.In this thesis,through strain engineering,the adjustment of the wetting properties of monolayer Mo S2 at the nanometer scale is realized,which provides a theoretical basis for the preparation of Mo S2 micro-nano devices and the determination of device application scenarios. |
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