Preparation And Properties Of Superhydrophobic/Superoleophilic Silica/Poly(ether Sulfone)s Composites

Superhydrophobic materials have been applied extensively in many fields because of their excellent corrosion resistance,anti biological adhesion,anti ice,oil-water separation ability and self-cleaning ability.However,superhydrophobic materials with excellent performance usually need complex preparation process or polluting and expensive fluorine-containing materials.Therefore,the environment-friendly superhydrophobic materials with stable hydrophobicity have attracted attention from all walks of life.The polymers based hydrophobic composites are considered to be good hydrophobic materials with excellent economic applicability and functionality than others.Polyethersulfone?PES?is one good engineering plastic with their chemical stability,outstanding mechanical properties,thermodynamic stability,corrosion resistance and strong film-forming ability.Moreover,PES is often used as a superhydrophobic/superoleophilic functional coatings or separation membrane materials due to its strong good alteration of wettability.Inorganic micro-nano particles not only have good dispersibility,hardness,chemical resistance,chemical stability,but also different particles sizes can enhance the roughness of the materials.Therefore,in order to consturcting rough micro/nanostructured surfaces with low surface energy,the introduction of a combination of inorganic SiO₂ particles of different sizes and low surface energy substances into the system will not only enhance the hydrophobic properties of surfaces,but also give the substrate excellent mechanical properties and corrosion resistance.The cage silsesquioxane?POSS?is one nano-sized particles material,which are organic groups instead of inorganic silicone skeleton.Integrating POSS into polymers system,not only the mechanical and thermal,and hydrophobic properties of the polymers matrix have been obviously improved,but the antioxisdant performance,UV corrosion resistance,and chemical stability are all significantly enhanced.In this work,based on the bionics aboutlotus leaf theory,multi-layered asymmetric porous SiO₂ composite PES separation membranes were prepared by phase separation and sol-gel method.Separation membranes have excellent superhydrophobic/superoleophilic properties,and excellent water repellency.The WCA is up to 155°,the rolling angle is less than 3°,and the OCA is less than 10°.Superhydrophobicitymaintain stable at different pH?1-13?conditions.And composite membranes can efficient separate emulsifiers stabilized and no containing surfactant water-in-oil emulsions.The separation efficiency is over 99%,the flux is 2300m^-2h^-1bar^-1,the separation efficiency can be maintained after 15 cycles of experiments separation effect.Besides,the separation membranes have excellent chemical stability and can effectively separate corrosive 1 mol L^-1NaOH,1 mol L^-1 H₂SO₄,and 1 mol L^-1NaCl emulsions in the range of 25-65°C.To obtain functional and applicable superhydrophobic materials,a multi-layered structured POSS and SiO₂ composite polyethersulfone coatings were prepared by spraying method.These coatings also possesssuperhydrophobicand superoleophilic properties,with a WCA of up to 157.1°,a sliding angle of less than 5°,and an OCA of less than 10°,also have excellent self-cleaning properties.Under immersing in a highly corrosive solution?pH=1,13?for 32h and irradiated with ultraviolet radiation for 10h,the coatings still maintained good superhydrophobicity.The composite coatings were sprayed on porous stainless steel meshs for preparing superhydrophobic/superoleophilic compound omenta,and the omenta were evaluated about oil/water separation performance.The results showed that the efficiency of separating oil-water mixture and water-in-oil emulsion under gravity is as high as99.2%,the flux can reach 6850 ml h^-1,and the stable separation effect is maintained after 20 cycles of experiments.