Fabrication Of 3D Micro-Nanostructure Superhydrophobic Materials And Their Application In Oil-Water Separation

With the development of industry,water pollution caused by the increase of oil spills frequently occurs.Efficient and rapid treatment of polluted water resources has caused widespread concern around the world.In recent years,new superhydrophobic materials for oil-water separation have been widely eoncerned.In the preparation of superhydrophobic material,the surface with a rough structure and low surface energy is required.Usually,the construction of micro-nano structure is used to obtain rough structure.Then,surface energy is modified to finally fabricate the superhydrophobic material.However,the synthesis steps of many materials are complicated,costly and harmful to environment.These problems prevent them from being used in actual oil-water separation.Therefore,in this paper,three environmentally friendly superhydrophobic materials were synthesized and used to achieve efficient oil-water separation.The main research work is as follows:The 3D hierarchical micro-nanostructure CuO microspheres loaded superhydrophobic sponge material was synthesized and effectively applied for oil-water separation.The CuO microspheres were stacked and fixed on the melamine sponge skeleton by using aminopropyltriethoxysilane(APTES)and stearic acid(STA)as a binder to improve surface roughness.At the same time,long alkyl chain in STA caused the decrease of surface energy.The water contact angle of prepared superhydrophobic CuO@APTES@STA material was 154°.The material could not only directly absorb the oil,but also perform the continuous oil-water separation by means of the peristaltic pump.The saturated absorption capacity was up to 15-53 times of its own weight and the separation efficiency was up to 96.6%.In addition,the material could maintain stable absorption capacity,separation efficiency and hydrophobicity after 10 cycles of oil-water separation,demonstrating its good recycle performance.The 3D pine needle-like hierarchical micro-nanostructure CoOOH loaded superhydrophobic sponge material was designed and synthesized.The CoOOH nanoneedles were grown in different directions and arranged on the sponge skeleton to improve the surface roughness of the material.Furthermore,the material was modified with stearic acid(STA)to reduce the surface energy.The superhydrophobic CoOOH@STA material was obtained,and the water contact angle was 155°.In oil-water separation applications,the material could directly absorb and remove the oil from the oil-water mixture and be used for continuous oil-water separation by means of a peristaltic pump.The saturated absorption capacity was up to 20-50 times of its own weight,and the separation efficiency was up to 96.2%.In addition,the CoOOH@STA material had excellent recycling performance and coxild maintain stable absorption capacity,separation efficiency and hydrophobicity after 10 cycles of oil-water separation.The 3D marimo-like hierarchical micro-nanostructure superhydrophobicβ-FeOOH microspheres(FeOOH@SDS)anchored superhydrophobic sponge/cotton fabric materials were designed and synthesized for efficient oil-water separation.FeOOH@SDS microspheres were formed by self-assembly of β-FeOOH nanorods which tended to stack up to each other in an orderly manner under the modification of sodium dodecyl sulfate(SDS)to improve the surface roughness of the material and reduce surface energy.The water contact angles of superhydrophobic materials were 150° and 168°.The materials could directly absorb oils and be used in continuous oil-water separation by means of peristaltic pump and funnel.The saturated absorption capacity was between 1.56-22.82 g/g.The separation efficiency could reach above 97.5%.In addition,FeOOH@SDS sponge and cotton fabric could maintain stable absorption capacity,separation efficiency and hydrophobicity after 10 cycles of oil-water separation,which performed satisfactory reusability.