Oil-Water Separation Performance Research Of Copper Mesh Fabricated By Laser With Graphene-Based Modification

In daily life,oil pollution management has always been a hot issue in the process of protecting the environment.Different from the traditional oil/water separation methods,the new oil/water separation method based on the control of surface wettability of the materials has received extensive attention.As a new type of high-efficiency,fine and non-secondary pollution processing technology,laser plays a vital role in constructing the surface microstructure of materials to further change the surface energy of the material and obtain the desired surface wettability.At the same time,the appearance of graphene materials has become one of the absolute hotspots of scientific research in recent years due to its excellent physical and chemical properties.Various derivatives based on graphene materials have also begun to enter the field of vision,and graphene-based materials typified by hydrophilic graphene oxide and hydrophobic fluorinated graphene have also become possible in controlling surface wettability.In this paper,copper with better physicochemical stability as the substrate material was used to study the change of wettability of the copper surface of the substrate and the influence of the actual oil-water separation application under different laser processing processes and deposition of graphene-based materials.The related mechanisms of laser ablation,surface wettability and the action of graphene materials were discussed.Mainly can be divided into the following parts;(1)Laser ablation directly treats the surface of the copper sheet,designs and obtains the required surface micro-nano structure,realizes the oil-water separation function,and studies the influence of different laser processing parameters on the performance indexes of oil-water separation.In this study,the surface micron-scale structure of the oil-water separation copper mesh was formed by constructing a concentric annular line and a circular through-hole array on the copper surface.At the same time,other copper and copper oxides that are sputtered and melt redeposited form surface nanostructures during laser ablation.Under the joint action of micro-nano structure,the copper mesh is super-hydrophilic,and it is super-oleophobic under water.When the diameter of the prepared hole is 0.2 mm and the spacing of the ring line is 0.1 mm,the underwater oil contact angle could even reach 167°.With this property,the function of separating the oil-water mixture is realized.On the basis of realizing the function,the influence of the copper mesh with different surface structure on the oil-water separation rate and the maximum oil load can be studied.(2)Based on the research(1),the hydrophilic graphene oxide material was introduced and deposited on the surface of the laser treated copper mesh by electrophoresis.The properties of hydrophilic graphene oxide on oil-water separation copper mesh were studied.Enhancement.Graphene oxide has a hydrophilic oxygen-containing functional group and a strong adsorption property rich in its surface,and theoretically it is possible to increase the separation rate of the oil-water separation copper mesh.By adjusting the different deposition time and the concentration of graphene oxide solution under electrophoresis,the deposition amount of graphene oxide on the surface of copper mesh was changed,and the enhancement effect of oil-water separation performance was studied and realized to some extent.(3)Based on the previous two-step research experience and the lack of research results,the effect of electrostatic spray coating on the surface of commercial flexible copper mesh in oil-water separation was studied.The oil-water separation copper mesh in(1)and(2)is made of a hard copper plate and can only be fixed at a certain place for separation,and the stability of the graphene oxide film under electrophoresis needs to be improved.The electrostatic atomization spray method used in this study enhances the adhesion of the graphene-based material to the surface of the copper mesh.At the same time,the flexible commercial copper mesh used in the improvement can be flexibly bent according to different use scenarios,and has greater practical value.After dragging 2000 mm on 1200 grit sandpaper under a constant pressure of 1 kPa,the hydrophobic angle remains above 140°,which has good wear resistance.The result of the cyclic separation test showed that the separation performance of the copper mesh did not decrease after repeated separation and washing for 10 times,and the separation efficiency exceeded 98%,which had excellent performance.