Fabrication Of Superhydrophilic And Underwater Superoleophobic Surface And Its Research Of Oil/Water Separation

Producing a large volume of wastewater in daily production and life,the discharged oily wastewater would produce serious environmental pollution,and endanger to health.Therefore,the research on separation of water and oil has important significance on improving the quality of water and oil.Superhydrophilic and underwater superoleophobic strainer is an efficient tool for separation of water and oil from oil/water mixture on the basis of the difference of wettability when water droplets and oil droplets are dropped upon the sample sufaces.This paper is to propose two methods to fabricate superhydrophilic and underwater superoleophobic strainer mesh on the basic materials of copper mesh and stainless steel mesh,and to design an oil/water separation device in order to do a research on a series of factors affecting oil/water separation efficiency.The main research contents and results are showed as followings:1.The copper mesh was soaking by sodium hydroxide and potassium persulfate solution to prepare superhydrophilic and underwater superoleophobic strainer mesh.The microstructure and chemical composition were analyzed via SEM and XRD.The influence of the pore size,initial oil content,the recycle times on the oil/water separation were analyzed.The results showed: the micro-nano structure with copper hydroxide was formed on strainer mesh via this method,which the contact angle of water droplet in the air was 0°and oil(1,2-dichloroethane)in water reached 159°.The strainer mesh can separate different oil/water mixture effectively,such as petroleum ether n-hexane,etc.The separation efficiency can reach more than 90%.Meanwhile,the strainer mesh can be reused for more than 20 times.To some extent,serried mesh structure promoted the separation efficiency.In addition,the superhydrophilic and underwater superoleophobic copper mesh immersed in PH for 1 hydrocholric acid and seawater two kinds of corrosive liquid,the oil/water separation efficiency was not significantly reduced,showing certain corrosion resistance.2.Nanostructure with zinc oxide was successfully grown on 201 stainless steel mesh in Hexamethylenetetramine and zinc nitrate solution via hydro-thermal method,preparing superhydrophilic and underwater superoleophobic strainer mesh.The microstructure and chemical composition were analyzed via SEM and XRD.The influence of the pore size,initial oil volume,the recycle times on the oil/water separation were analyzed.Meanwhile,the corrosion resistance in sodium hydroxide and seawater solution were studied.The results showed: the stainless steel mesh was covered with zinc oxide,which showed superhydrophilic in the air and superoleophobic in the water.By using of hydrophilicity of zinc oxide and the nature of stainless steel mesh,The strainer mesh can separate different oil/water mixture effectively,such as petroleum ether,n-hexane,etc.The separation efficiency can reach more than 80%,and the strainer mesh can be reused for more than 20 times,and showed certain corrosion resistance.