Here we presented a novel technology to achieve a Super-hydrophobic coating with microscopic roughness oncopper surface. First, make a layer of verdigris grow on the fresh pure copper surface. Gain it by exposing thec...Here we presented a novel technology to achieve a Super-hydrophobic coating with microscopic roughness oncopper surface. First, make a layer of verdigris grow on the fresh pure copper surface. Gain it by exposing thecopper to air and the mist of acetic acid solution. The green coating is a mixture of basic copper(Ⅱ) carbonate andcopper(Ⅱ) acetate. Second heat the coating and make it decompose to CuO. Lastly, form an n-octadecanethiolself-assembled monolayers coating on the outermost surface. Contact angle test, scanning electron microscopeanalysis and electrochemical testing were carried out to characterize the surface, and a heat transfer experimentfor dropwise condensation of steam was performed also. Results show that the modified surface bears a few Super-hydrophobicfeatures, the static contact angle is higher than that in literatures, reaching 153.1±1.7°. The microscopicroughness can be seen in SEM images, differing much from H2O2 etched surface and bare copper surface.The condensation of steam on the surface is a typical form of dropwise condensation, in the measured rangeof temperature difference, under 0.1 MPa, the average convection heat transfer coefficients of the vertical surfaceare 1.7～2.1 times for those of film condensation. At the same time, the inhibition efficiency of surface is improvedto some extent comparing with the same kind of SAMs, which suggests that the lifetime of maintenancedropwise condensation would have the possibility to surpass the existing record.展开更多
基金supports of the National Natural Seience Foundation of China (Grant No.50706053)the National High Teelmology Research and Development Program of China(863 Prograrn,Grant No.2007AA052259) are gratefully acknowledged.
文摘Here we presented a novel technology to achieve a Super-hydrophobic coating with microscopic roughness oncopper surface. First, make a layer of verdigris grow on the fresh pure copper surface. Gain it by exposing thecopper to air and the mist of acetic acid solution. The green coating is a mixture of basic copper(Ⅱ) carbonate andcopper(Ⅱ) acetate. Second heat the coating and make it decompose to CuO. Lastly, form an n-octadecanethiolself-assembled monolayers coating on the outermost surface. Contact angle test, scanning electron microscopeanalysis and electrochemical testing were carried out to characterize the surface, and a heat transfer experimentfor dropwise condensation of steam was performed also. Results show that the modified surface bears a few Super-hydrophobicfeatures, the static contact angle is higher than that in literatures, reaching 153.1±1.7°. The microscopicroughness can be seen in SEM images, differing much from H2O2 etched surface and bare copper surface.The condensation of steam on the surface is a typical form of dropwise condensation, in the measured rangeof temperature difference, under 0.1 MPa, the average convection heat transfer coefficients of the vertical surfaceare 1.7～2.1 times for those of film condensation. At the same time, the inhibition efficiency of surface is improvedto some extent comparing with the same kind of SAMs, which suggests that the lifetime of maintenancedropwise condensation would have the possibility to surpass the existing record.
