| Human daily life and industrial production producted a large amount of oily wastewater,which has caused serious harm to environment.However,oily wastewater treatment technologies still have enormous challenges such as high difficulty,environmental pollution,low efficiency and high cost.In recent years,with the development of superhydrophobic material theory and preparation technology,membranes with special wettability for oil-water separation have been extensively studied.Special wettability materials provide a new way for effective oil-water separation.However,due to high cost and complicated preparation processes,which seriously effect their practical application,these materials with special wettability,simple process and low cost,and high efficiency separation are still challenge.In this study,we provide two methods to preparing materials with special wetting properties.(1)A layer of candle shoot was collected on the surface of the 240 mesh stainless steel mesh and then the stainless steel mesh collected with candle shoot was immersed in the PDMS solution.Afer treatment metion above collected candle shoots.Finally,heated in oven 80 ° C 2 h.A superhydrophobic stainless steel mesh with candle shoots was prepared with water contact angle 156° and the sliding angle is about 3°.Conversely,when cyclohexane is dropped onto the surface of the superhydrophobic stainless steel mesh,the liquid spreads rapidly on the surface of the superhydrophobic stainless steel mesh and absorbed,indicating that the surface of was superlipophilic and the oil contact angle was 0°.The superhydrophobic stainless steel mesh surface has self-cleaning behavior.Moreover,the contact angle of hot water temperature of 90 ° C can reach 145 °,and the liquid contact angle for acid and alkali is 143 °.At the same time,it has good anti-pollution performance.The superhydrophobic surface prepared by the secondary collection has good mechanical stability,and maintains good hydrophobic properties after 10 times of tape peeling test and water flow impact for 10 min.In addition,the superhydrophobic stainless steel can be macroscopically effective in separating a mixture of dichlorometh ane and water.(2)The displacement reaction of silver nitrate with copper formation of silver micro/nano structures on the surface of the copper mesh.The 30 s is the suitable reflection time,the prepared Cu-Ag has a superlipophilic/superhydrophilic property with a contact angle of 0° for water and oil and has an underwater oil contact angle of 132° and underoil water contact angle of 139°.The pre-wetting of Cu-Ag by water can effectively separate the mixture of vacuum pump oil and water mixture and the efficiency of oil-water separation during the ten cycles is greater than 94%.(3)PDMS was coated on the surface of Cu-Ag.From the EDS and FTIR results indicated that PDMS was successfully coated.We recorded the PDMS modified material as Cu-Ag-P.And Cu-Ag-P has a water contact angle of 153° with high flux for DMF(~31000 L * m-2 * h-1),excellent anti-icing and self-cleaning properties.In addition,the coated mesh still exhibits excellent water contact angle after UVB,mechanical abrasion,hot water and acid/alkaline solution treatment.In addition,the coating mesh connected to the vacuum pump was used for continuous oil-water separation.This work not only provides a simple and effective way to make a controlled wettability copper mesh with oil/water separation and also provides a new idea for the potential application of continuous oil-water separation. |
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