Mechanically Robust Superamphiphobic Aluminum Surface with Nanopore-Embedded Microtexture

Abstract

A simple fabrication technique was developed for preparing a mechanically robust superamphiphobic surface on an aluminum (Al) plate. Dual geometric architectures with micro- and nanoscale structures were formed on the surface of the Al plate by a combination of simple chemical etching and anodization. This proposed methodology involves (1) fabrication of irregular microscale plateaus on the surface of the Al plate, (2) formation of nanopores, and (3) fluorination. Wettability measurements indicated that the fabricated Al surface became super-repellent toward a broad range of liquids with surface tension in the range 27.5-72 mN/m. By varying the anodization time, we measured and compared the effects of morphological change on the wettability. The adhesion property and mechanical durability of the fabricated superamphiphobic Al surface were evaluated by the Scotch tape and hardness tests, respectively. The results showed that the fabricated Al surface retained mechanical robustness because the down-directed surface made by nanopores on the microtextured surface was durable enough even after high force was applied. Almost no damage of the film was observed, and the surface still exhibited superamphiphobicity after the tests. The fabricated superamphiphobic surface also remained stable after long-term storage. The simple and time-saving fabrication technique can be extended to any large-area three-dimensional surface, making it potentially suitable for large-scale industrial fabrications of mechanically robust superamphiphobic surfaces.

Mechanically durable superoleophobic aluminum surfaces with microstep and nanoreticula hierarchical structure for self-cleaning and anti-smudge properties

“…Separate nanostructured surface and microstructured surface were fabricated, to compare with the hierarchical surface. Nanostructured surface was fabricated through one-step etching in HNO 3 and Cu(NO 3 ) 2 , while the microstructured surface was obtained from one-step HCl etching. Finally, the finished samples of nanostructured, microstructured, and hierarchical surfaces were dipped into 1.0 wt% ethanol solution of [1H, 1H, 2H, 2H-Perfluoro decyltriethoxysilane]PDES (Sigma-Aldrich, #658758) for 2 h by dip coating technique and then annealed at 100°C for 30 min.…”

“…Various techniques, including chemical etching and anodization techniques, have been used to produce superhydrophobic aluminum surfaces. Chemical etching method with various chemical etchants including boiling water [31,15], NaOH [12,22], HCl [30], ZnNO 3 Á6H 2 O [39,24], HNO 3 combined with Cu(NO 3 ) 2 [11,23], AlCl 3 combined with triethanolamine [21], La(NO 3 ) 3 [20], and FeCl 3 [25], and anodization method, with various electrolytes including oxalic acid [19,27], mixed solutions of NaCl and fluorosilane [33], have been used to prepare superhydrophobic aluminum surfaces. In the above-mentioned papers, nanoplatelet, microstep, nanoreticula, microflower, and nanowire structures have been created to achieve superhydrophobicity.…”

“…Another example is electrochemical etching in Na 2 SO 4 combined with anodization in oxalic acid, and subsequent fluorosilane coating [38]. Chemical etching in HCl combined with anodization in H 2 SO 4 followed by fluorosilane coating is another method [3]. Electrochemically etched in NaCl combined with chemically etched in [Ag(NH 3 ) 2 ] + solution, and with subsequent fluorocarbon acid coating [32] has also been reported to obtain superoelophobic surface.…”

“…A few papers have reported some mechanical durability data. Barthwal et al [3] reported a superoleophobic aluminum surface that shows durability to an adhesive tape. Peng et al [28] reported data on resistance to adhesive tape, blade scratching, and abrasion tests, as well as self-cleaning effect.…”

Analysis of wear abrasion resistance of superhydrophobic acrylonitrile butadiene styrene rubber (ABS) nanocomposites

“…Since superhydrophobicity requires combination of hierarchical surface texture with hydrophobic chemistry [21][22][23], the most common strategy for improving and maintaining robustness should involve preservation of micro and nano-scale features associated with the surface topography and the hydrophobic surface chemistry during and after wear abrasion. This is evaluated by performing mechanical abrasion cycles (with constant speed and applied pressure) where the tested superhydrophobic surfaces are abraded by different kinds of abradants that produce different types of wear patterns [24][25][26][27][28][29].…”