The Establishment And Verification Of Oil-water Separation For Super-Amphiphobic Mesh Based On Low Surface Free Energy Theory

In recent years,efficient oil-water separation technology is widely used in production and life.Among the oil-water separation methods,the mesh separation method plays an important role in some production processes,but the traditional lipophilic hydrophobic mesh is easy to be contaminated,and the hydrophilic oleophobic mesh has the disadvantage that the hydrophilic group is easy to dissolve and has bad durability,the controllable wettability theory are not mature,these disadvantages result that the mesh is less efficient and costly.The super-amphiphobic surface(super-hydrophobic/super-oleophobic surface)has the advantages of great durability,anti-pollution and strong repeatability,which has important theoretical significance and practical value in sewage treatment,oil purification,crude oil exploitation and marine oil pollution control,and has broad application prospects.In this paper,a method of oil-water separation using super-amphiphobic mesh was proposed.According to the principle of oil-water separation with super-amphiphobic mesh,two oil-water separation forms are determined.The geometrical and physical relations of the contact between liquid and solid at the reticular cross section during oil-water separation were studied.The Laplace pressure difference equation and the external pressure difference equation of the liquid surface,the distance between the upper and lower liquid surface of the reticulum and the geometric angle equation were established,and the model was extended to three-dimensional space.Through the model,the minimum pressure and the maximum pressure are obtained.The effects of pressure on both sides of the mesh,contact angle of the mesh,diameter of the mesh,ratio of the aperture of the mesh to the diameter of the mesh on the pressure were analyzed.Based on the theory of surface free energy and surface roughness,fluoride was chemically bonded to the surface of solid particles to obtain low surface free energy.The particles were sprayed onto the stainless steel mesh to form a low free energy surface with a certain roughness.The experiment of single factor's influence on pressure was designed by controlling other factors on oil-water separation.By comparing the experimental data with the theoretical model,the differences between the experimental results and the theoretical model are analyzed,and the model is further modified to obtain a model with guiding significance for the parameter selection of oil-water separation mesh.