Surface Modification of Aluminium Alloy with Super Hydrophobic Characteristics using Immersion and Spray-Coating Method

The surface of a thin aluminum alloy with thickness of 0.103 mm was modified using immersion method to produce high water contact angle of more than 150° which constitutes a super-hydrophobic surface characteristics. Contact angle was measured using a digital goniometer and the modified surfaces were examined under a scanning electron microscope. Apart from immersion technique, spray-coating method was also employed to modify the surface of the aluminum alloy for comparison. The results of surface modification with immersion method shown a higher water contact angle than the spray-coating method by 56%. The weight of the samples were also measured before and after the etching process. Previously, the conventional immersion method is only well-suited for a thick material whereas the thin material can be easily dissolved with the conventional formula. Initial immersion method fully dissolved the thin aluminium alloy strip. Thus, the immersion method was modified and effectively produced a super-hydrophobic surface with contact angle of 160° for the thin aluminium alloy with only 10% weight loss.