Preparation And Properties Of Superhydrophobic/Superoleophilic Stainless Steel Mesh Membrane For Oil-Water Separation

The rapid development of society and economy has brought benefits to human beings,and at the same time,a series of thorny problems have emerged,among which the treatment of oily wastewater has become an urgent matter.Traditional oil-water separation methods have disadvantages such as high energy consumption and low separation efficiency,so it is very important to find a new high-efficiency oil-water separation technology.Inspired by the phenomenon of superhydrophobicity in nature,this thesis prepared superhydrophobic/superoleophilic coatings for oil-water separation by constructing rough surface micro-nanostructures and reducing surface energy.In this paper,a fluorine-containing siloxane modifier was obtained by reacting hexafluoropropylene oxide dimer with methanol and KH792;Another fluorine-containing siloxane modifier was obtained from hydroxyethyl methacrylate,KH792.The products were characterized by FT-IR and ~1H NMR.F-HNTs and FHEMA-N-HNTs were prepared by grafting two modifiers on halloysite nanotubes(HNTs),respectively.Modified HNTs were characterized by FT-IR,TG,TEM,EDS,etc.TTwo superhydrophobic/superoleophilic coated stainless steel meshes,F-HNTs/EP and FHEMA-N-HNTs/EP,were prepared by mixing the above two modified HNTs with epoxy resin uniform Ly and then spraying them on the stainless steel mesh.The Water contact angle(WCA)of F-HNTs/EP coated mesh was 155.4±0.3°,which can separated oil-water mixtures of different systems,and the separation efficiency were higher than 97.8%,the separation efficiency was still higher than96.2%after 50 cycles of separation;The WCA of FHEMA-N-HNTs/EP coated mesh was155.8±0.3°,a series of oil-water mixtures can be separated by the coated mesh,and the separation efficiency were higher than 97.9%,the separation efficiency was still higher than98.6%after 50 cycles of separation.Oil-water mixtures with different oil-water volume ratios and different p H value can be efficiently separated with the two prepared stainless steel coated meshes,and they still showed excellent stability under harsh test conditions,such as strong acid,strong alkali,and sandpaper abrasion.HNTs-SH was obtained by grafted(3-mercaptopropyl)trimethoxysilane with halloysite nanotubes.Then,2-(perfluorohexyl)ethyl methacrylate was reacted with HNTs-SH through a click reaction to obtain HNTs-SH-F,and its structure was characterized by FT-IR,TG,EDS,etc.The HNTs-SH-F/EP superhydrophobic/superoleophilic coated mesh was prepared by spraying the mixture of epoxy resin and HNTs-SH-F onto the surface of the stainless steel coated mesh,WCA was 156.1±0.7°.The coated mesh can not only separate the different oil-water mixture with the separation efficiency higher than 98%,but also can be recycled,and the separation efficiency were still higher than 98.9%after 50 cycles of separation;Oil-water mixtures with different p H water/oil systems and oil/water extreme volume ratios can be separated.Meanwhile,the coated mesh had good friction resistance,strong acid resistance,strong alkali resistance,and excellent comprehensive performance.