Optimization of Super-Hydrophobic Property by Two-Step Surface Modification

The super-hydrophobic surface can be used in anti-pollution, self-cleaning, and anti-corrosive properties. Two-step surface treatment process on Al-coated glass was conducted by surface etching using potassium hydroxide (KOH) and surface coating using lauric acid for super-hydrophobic surface. The KOH-etched Al surface (1st etching) was changed to a hydrophilic property with a water contact angle (WCA) of 68 degrees to 48 degrees. On the other hand, the WCA of the etched Al surface was changed to about 153 degrees with super-hydrophobic property when the lauric acid coating (2nd coating) was applied on the KOH-etched Al surface for 30 minutes. We found that the hydrophobicity of Al surface was related to the roughness by surface modification as well as the Al film thickness by sputtering method.