Fabrication of Superhydrophobic Al5083 Aluminum Alloy for Marine Applications

Abstract

Considering the importance of Al5083 as a most used and most promising aluminium alloy in vessels hull and marine systems, the focus of this research is on access to superhydrophobic coatings on this alloy by economical and efficient two step method composed of anodizing and chemical modification with silane. Al5XXX series of Al alloys including Al5083 have been widely used in marine industries such as fast ferries and ship building. In the present research, for fabricating superhydrophobic coatings on the aluminum alloy (Al5083) surface, anodizing in sulfuric acid and chemical modification of triethoxy octyl silane (KH-832) and 1H, 1H, 2H, 2H–perfluorooctyl trichloro silane (PFOTS), was employed. Surface characterization was carried out by scanning electron microscopy (SEM), atomic force microscopy (AFM), and ATR-FTIR tests. Also, the wettability of superhydrophobic coatings was evaluated using static wettability test. Static wetting and contact angle hysteresis tests on the aluminum alloy surfaces provided a high contact angle (about 170 and 160 degrees) and low contact angle hysteresis (about 3 and 9 degrees) respectively by modification with KH- 832 and PFOTS as a non-wettable surface. The ATR-FTIR analysis after surface chemical modification with KH-832 and PFOTS showed functionalized groups.