Study on Wettability of Aluminum Alloy Superhydrophobic Surface

Wettability is interfacial phenomena by a solid interface changes from solid-gas interface to solid-liquid interface, and the contact angle is often used to characterize it. The super hydrophobic surfaces with contact angle over 150° have various excellent characteristics. In the paper, the wettability of aluminum alloy surfaces was studied. Based on the Wenzel and Cassie models, the relationship of wettability between roughnesses were investigated on body surface and coating surface. The results indicated that the hydrophobicity of surfaces could greatly enhance with high roughness on surface, and then coating process was analyzed, wettability of aluminum alloys were transformed from hydrophilicity to superhydrophilicity, when they were coated with organic materials with the low surface free energy, such as polypropylene (PP) or maleic anhydride grafted polypropylene (PP-g-MAH), so modified PP can enhanced the hydrophobicity of solid surface mostly.