Studies On Fabrication Of Superhydrophobic With High Adhesion Force Surface On Aluminum Substrates

Super-hydrophobic materials with high adhesion force always possess not only a large contact angle (greater than 150°), but also a good adhesion with water. It has been a new focus for the potential applications in liquid transportation, biochemical separation, in situ detection, and localized chemical reaction. In this study, for the first time, surface with high adhesion force of superhydrophobic thin films was prepared with aluminum alloy substrate.In this paper, ZnAl-LDHs films were prepared by hydrothermal method on anodized aluminum substrates. The prepared films show superhydrophobic and high adhesion force properties after modifing with sodium laurate. Then, the influence factors such as anodic oxidation process of polishing, anodic oxidation time, hydrotalcite process of Zn/NH3 molar ratio of experimental parameters, temperature and time were investigated.XRD analysis indicated the formation of ZnAl-LDHs film. Morphology of the ZnAl-LDHs films were investigated by SEM, which shows that the film thickness is about 3μm, the growth direction of LDHs crystal is perpendicular to the substrate, and the curved laminates formed porous structures with pore size of less than 500 nm. Contact angle measurements show that the measured contact angle of the ZnAl-LDHs film is greater than 150.0°after surface modification with sodium laurate, which has achieve superhydrophobicity. In order to obtain better hydrophobic property, orthogonal experimental design was used to achieve the optimal parameters: anodic oxidation time of 65 min, Zn/NO3 concentration ratio of 1:6, temperature of 95 oC, and time of 36 h. The hydrophobic angle of the film prepared with the optimal paremeters can be increased to 156.4°. Finally, ZnAl-LDHs film surface wetting properties and applications of the material were discussed. Organic solvents glycerol, ethylene glycol and dimethyl sulfoxide contact angle measurements showed that the material and organic solvents have great contact angle, upside down and found the material, and organic solvents have a strong adhesion force, and the adhesion force as inhanced by the increasing of solvent viscosity. This paper also analyzed the stability and solvent resistance of the hydrophobic films. Contact angle analysis showed that the films have good stability and solvent resistance hydrophobic.In summary, this study paves a new approach for preparation superhydrophobic materials with high adhesion force. Moreover, the analyses of nanostructure and chemical composition of the superhydrophobic and high viscosity supply theoretial base for deeper understanding and application of superhydrophobic surface.