Production and Characterization of Stable Superhydrophobic Surfaces Based on Copper Hydroxide Nanoneedles Mimicking the Legs of Water Striders

Abstract

The present work reports a simple and economic route for production and characterization of stable superhydrophobic surfaces from thin copper layers coated on arbitrary solid substrates. The thin copper layer was anodized in a 2 M aqueous solution of potassium hydroxide to form a thin film of copper hydroxide nanoneedles; then the film was reacted with n-dodecanethiol to form a thermally stable Cu(SC12H25)2 superhydrophobic coating. The contact angle of the modified nanoneedle surface was higher than 150 degrees , and its tilt angle was smaller than 2 degrees . Furthermore, the surface fabricated on copper foil kept its superhydrophobic property after heating at 160 degrees C in air for over 42 h. This technique has also been applied for fabrication of copper wire with superhydrophobic submicrofiber coating to mimic water strider legs. The maximal supporting force of the superhydrophobic copper column has also been investigated in comparison to real water striders.

Synthesis, characterizations and hydrophobicity of micro/nano scaled heptadecafluorononanoic acid decorated copper nanoparticle

“…Super hydrobhopic surfaces based on copper hydroxide nano needles were reported by Wu and co-workers [12]. Wang and his research team [13] studied the super hydrophobic copper films.…”

Wire-like Bundle Arrays of Copper Hydroxide Prepared by the Electrochemical Anodization of Cu Foil

“…[14][15][16] This method is a convenient, environmentally friendly, and time-saving process compared to conventional methods. Based on this procedure, copper mesh with superhydrophobic and superoleophilic properties was readily fabricated and applied to a novel filtration device for the separation of water and hydrophobic solvents.…”

Mimicking water striders’ legs superhydrophobicity and buoyancy with cabbage leaves and nanotube carpets

“…25,26 As a matter of fact, the special ability of water striders to walk quickly on the water surface and the superhydrophobicity of their legs, which are connected to the nanostructured surface microstructure, had attracted considerable attention in the scientific community. [27][28][29] In this paper, two hierarchical hydrophobic surfaces, natural or artificial, with surface structures similar to those of the water strider's leg (G. remigis), are compared in terms of wettability and floating capability. They are the upper (adaxial) and lower (abaxial) sides of the natural cabbage leaf of Brassica oleracea 9,30 and the hydrophobic side of a vertically aligned carbon nanotubes (VACNTs) carpet.…”

“…33 At the same time, few water strider-like models with large and stable loading capacity were fabricated using the previous superhydrophobic surfaces with the shape of a wire, a mesh, or a foil. [26][27][28] To understand the effect of the morphology on surface wetting properties, this paper develops a surface characterization in terms of wettability through measures of CA, TA, sliding volume (SV), and sliding speed (SS), as defined in previous papers, 21,34 and through field emission scanning electron microscopy (FESEM) micrographs. The aim was to observe and to discuss their superficial morphologies, which are similar to the surface of the water strider's leg.…”