OPTICALLY TRANSPARENT GLASS WITH VERTICALLY ALIGNED SURFACE Al2O3 NANOWIRES HAVING SUPERHYDROPHOBIC CHARACTERISTICS

Abstract

We have shown in this paper that the self-ordered pore structure of anodic aluminum oxide (AAO) can be utilized as a basis to conveniently form large-area Al2O3 nanowire arrays on a glass surface. An aluminum oxide nanowire array has been produced by aluminum film deposition on glass followed by anodization, then simple chemical etching. The glass surface as prepared is highly superhydrophobic, with a contact angle as high as 169°. The thinness (~ 340 nm) and vertical alignment of the aluminum oxide nanowires with empty spaces in-between essentially contribute to maintaining the optical transparency of the glass substrate. Interestingly, substantially suppressed UV transmission in the ~ 300–400 nm spectrum region was observed with the presence of the Al2O3 nanowires on the glass substrate. Such a durable surface ceramic nanowire structure can be useful for producing superhydrophobic, self-cleaning glasses with a variety of potential applications such as UV protecting glass windows for high rise buildings with reduced consumption of water and cleaning chemicals for positive environmental effects.