Study On Fabrication Of Low-surface-energy Surface On Metallic Substrate

Due to the advantages such as self-cleaning, anti-drag, antifriction, resistance to pollution, inhibition of surface corrosion and oxidation, low-surface-energy surfaces have a bright prospect in self-cleaning materials, drag reduction materials, and biomedical materials.There are two methods which produce low-surface-energy surfaces, such as the embellishment of rough surface by low-surface-energy materials and the improvement of the surface roughness of the super-hydrophobic surfaces. However, the production of low-surface-energy surfaces needs expensive special equipment, and the process is complex, which affect the further application of low-surface-energy technique.In this dissertation, a new production method of low-surface-energy surfaces was developed based on the combination of theoretical analysis and experimental research, and the main results are as follow:1) The rules of solid surface energy varying with contact angle were deduced based on the contact angle method. It indicates that the solid surface energy decreases with the contact angle increasing. Besides, the comparison of the cylindrical surface and double cylindrical surface on the contact angle were researched. The results show that the double micro-structure method is more helpful to increase the contact angle, simplify the preparation process, and improve the mechanical stability of the low-surface-energy surfaces.2) A new technique combined chemical etching with fluorination treatment was developed to produce low-surface-energy surfaces on aluminum and carbon steels. The aluminum surface and carbon steel surface exhibit super-hydrophobic properties with water contact angle of 165.1°and 159.3°, respectively. Besides, the effects of etchant (HCL solution), etching time, baking temperature and F8261 soaking time on super-hydrophobic were researched. Furthermore, the formation mechanism of the surface microstructure of aluminum and carbon steel were investigated, and a better processing parameter was obtained.3) The analysis of aluminum surface morphology with scanning electron microscope shows that there is a labyrinth structure with plateaus and caves of micro-nanostructure, which plays an important role in the formation of super-hydrophobicity after the treatment of fluorination.