Influence Of The Surface Tension Of Water Environment On The Super-hydrophobic Surface Wettability Underwater

Super-hydrophobic surfaces have a broad application prospects in industrial and agricultural production and daily life.Building super-hydrophobic surfaces and researching its underwater wettability has important theoretical significance on some fields,such as marine antifouling,anti-drag underwater,oil processing and so on.Based on the stability of air trapped by super-hydrophobic underwater that our group researched in the past,this article researches the effect of the surface tension of water environment on the super hydrophobic surface's wettability underwater.Its main contents are as follows:1.Selecting phase separation methods,by adjusting the water content of the reaction system,we build successfully rough organic silane nanostructure on the glass with organic silane and organic fluorine silane.The contact angle of the surfaces with water and oil reached 150°/0° and 167°/150°.The surfaces showed super-hydrophobic/super-lipophilic and super-hydrophobic/super-oleophobic.Studies suggest that,when surface contacts with water,chemical composition with low surface energy and the rough nanostructure cause super-hydrophobic/super-lipophilic and super-hydrophobic/super-oleophobic.2.Adjusting the ratio of water and ethanol to change the surface tension of the water environment.Researching the effect of the surface tension of water environment on the two kinds of super-hydrophobic surface's(super-hydrophobic/super-lipophilic and super-hydrophobic/super-oleophobic)wettability underwater.With the reduction of surface tension of water environment,the contact angle of super-hydrophobic/super-lipophilic surface with oil goes from 0° to 168°;the contact angle of super-hydrophobic/super-oleophobic surface with oil goes from 0° to 121°.Studies suggest that,with the reduction of surface tension of water environment,the air that is trapped by super-hydrophobic/super-lipophilic underwater will gradually be replaced by water,the continuity of the air is destroyed.Water between the air hinder diffusion that oil droplets on the air/liquid interface.,the contact angle of the surface with oil increases;With the reduction of surface tension of water environment,the air that is trapped by super-hydrophobic/super-oleophobic is stable.The air underwater is continuous on the surface.Actual oil droplets spread on the air/liquid interface formed on the surface.This can be seen as in the air the oil droplets spread on the water.With the reduction of surface tension of water environment,in the air oil droplets becomes spherical from spreading completely on the water surface.