Preparation And Separation Mechanism Of Biomimetic Metal Based Oil/water Separation Surface

With the improvement of people's living standards,oil and its products are widely used in various fields of national economy,and its dosage is also increasing.Oily wastewater is a common pollution source of water resources,which has great harm to human survival environment and sustainable development.Therefore,the treatment of oily wastewater is an urgent problem to be solved.When the oily waste water is discharged into the water body,the reservoir will cover the surface of the water,which prevents the diffusion of oxygen into the water,so that the photosynthesis of algae is limited.If oily waste water is used to irrigate the fields,the oil will cover the surface of the soil and plants,thus causing damage to the crops.Due to the spread of water pollution,it will lead to the pollution of natural landscape.As a common phenomenon in nature,the wetting behavior of solid surface is a very important part in surface chemistry.In addition to the superhydrophobic properties,many biological materials have the characteristics of self-cleaning,antifouling,drag reduction,corrosion resistance,oil and water separation,which has a very broad application and development prospects.Based on the excellent properties of natural organisms,it is of great scientific significance and industrial value to prepare superhydrophobic surface with super hydrophobic and lipophilic properties.Therefore,this paper selects the porous metal mesh and copper foam as the substrate,including surface electrodeposition and oxidation deposition were successfully prepared by super hydrophobic surface preparation,microstructure observation system,the system analysis of the chemical composition,wettability,water through property.A superhydrophobic and superoleophilic copper mesh with excellent oil-water separation efficiency was successfully fabricated via electrodeposition and then surface modification with lauric acid.It was found that the as-prepared surface is bothsuperhydrophobic and superoleophilic,with static WCA values as high as 155.5°±3°and an oil contact angle(OCA)of 0°.Furthermore,the as-prepared surface exhibited excellent oil-water separation efficiency including petroleum,toluene,hexane,gasoline and diesel,even after being recycled 10 times.In addition,the as-prepared copper mesh shows self-cleaning character with water and chemical stability.Superhydrophobic and superoleophilic stainless steel meshes with excellent oil-water separation efficiency were successfully fabricated by a facile immersion process and then surface modification with stearic acid.The simple immersion process,in which surface roughness and low-surface-energy coating are the two dominant factors of superhydrophobicity,could be accomplished sequentially.It was found that the as-prepared surface is both superhydrophobic and superoleophilic,with the static water angle(WCA)as high as 153°±3? and oil contact angle(OCA)of 0?.Furthermore,as-prepared meshes can be applied to separate an oil-and-water mixture bidirectionally and exhibited excellent oil-water separation efficiency including petroleum,toluene,hexane,gasoline and diesel,even after being recycled ten times.A novel p H-responsive smart device has been developed for continuous separation of oil/water mixtures.Smart surfaces are obtained by electroless silver deposition followed by surface modification with a mixed solution of thiol containing carboxylic groups and methyl groups(HS(CH2)11CH3 and HS(CH2)10COOH).It was found that the wettability of the as-prepared copper foams can switch reversibly between superhydrophobicity and hydrophilicity according to their p H response.The as-prepared copper foam can easily remove the organic solvents either on water or underwater.Furthermore,the as-prepared copper foams can be applied to separate an oil-and-water mixture bidirectionally with high efficiency.This study provides a simple and environmentally friendly route to fabricate oil–water separation materials which have potential applications in industrial fields,such as in water treatment and petroleum refining.In particular,this smart surface is switchable under various p H conditions.