Alumina nanowire forests via unconventional anodization and super-repellency plus low adhesion to diverse liquids

Abstract

Multiple facet supported alumina nanowires are produced very efficiently in a very short time via high field anodization; upon modification with perfluorosilane, the surface becomes super-repellent towards a broad range of liquids, which includes (salted) water, water emulsion, common organic liquids like glycerol and alkanes, and a variety of lubrication oils including ionic liquids, poly(alpha-olefin), polydimethylsiloxane oils etc.

The design and applications of superomniphobic surfaces

“…The resulting surfaces displayed an apparent contact angle as high as y * ¼ 1521 and a rolloff angle a ¼ 91 with hexadecane. Wu et al 78 fabricated alumina nanowire forests by electrochemically etching aluminum foils to form a multi-faceted microstructure and subsequently anodizing the activated aluminum to the form the nanowires. Upon silanization with perfluorooctadecyl trichlorosilane, the surfaces displayed y * ¼ 1551 and 1531 and a ¼ 51 and 31 for rapeseed oil and hexadecane, respectively.…”

Superoleophobic surfaces: design criteria and recent studies

“…Wu et al 54 fabricated alumina nanowire forests by electrochemically etching aluminum foils to form a multifaceted microstructure and subsequently anodizing the activated aluminum to the form the nanowires. Upon silanization with perfluorooctadecyl trichlorosilane, the surfaces displayed superoleophobicity with static contact angles θ * = 155, 153 and 150°, and roll-off angles ω = 5, 3 and 12° for rapeseed oil, hexadecane and silicone oil (γ LV = 22 mN/m), respectively.…”

A superoleophobic textile repellent towards impacting drops of alkanes

“…Third, the surface energy of the substrate should be as low as possible [7,8,11]. Due to these quite intricate prerequisites up to now only a few surfaces have been reported on which low surface tension liquids such as hexadecane (γ = 27 mNm -1 ) [12][13][14][15][16], dodecane (γ = 24.9 mNm -1 ) [16,17], decane (γ = 23.4 mNm -1 ) [16], ethanol (γ = 22 mNm -1 ) [9], silicone oil (γ = 22 mNm -1 ) [14] or octane (γ = 21.1 mNm -1 ) [8] show superoleophobicity, meaning apparent contact angles above 150° and low sliding angles.…”