Fabrication of Hydrophobic Ni Surface by Chemical Etching

Abstract

Hydrophobic surfaces were successfully fabricated on pure nickel substrates by a one-step chemical etching process with different acidic solutions. The static water contact angle (SCA) of the etched Ni surfaces reached higher than 125°, showing excellent hydrophobicity. The examination of surface chemical compositions implied that there were almost no polar moieties on the surface after chemical etching, except part of the surface was oxidized. After chemical etching, the nickel surfaces became much rough with packed terrace-/crater-/thorn-like clusters. According to the analysis of surface composition and morphology, the hydrophobicity was evidently attributed to the rough microstructures on the etched Ni surface. The best hydrophobicity on Ni surface was produced with the SCAs as high as 140.0° by optimizing the etching time and etchants. The results demonstrate that it is possible to construct hydrophobic surfaces on hydrophilic substrates by tailoring the surface microstructure using a simple chemical etching process without any further hydrophobic modifications by low surface energy materials.

Direct laser writing of hydrophobic and hydrophilic valves in the same material applied to centrifugal microfluidics

“…Different studies have demonstrated that surfaces incorporating hydrophilic groups can exhibit super hydrophobic characteristics, underscoring the pivotal role of microstructures in determining the hydrophobicity of a surface. 58–61 In line with these findings, our experimental results for the femtosecond laser modified surfaces provide further support as we showcase that the generation of highly roughened surfaces added to wave like periodic patterns can generate hydrophobic surfaces even when showing the incorporation of hydrophilic groups, as shown by our XPS results.…”

Novel Superhydrophobic Copper Mesh-Based Centrifugal Device for Edible Oil–Water Separation

“…Recently, superhydrophobic materials prepared by etching, , electrochemical deposition, , spraying, , and hydrothermal methods , have found good industrial applications due to their special functions such as self-cleaning and scale inhibition . Oil–water separation is a typical application example of superhydrophobic materials .…”

One-Step Methods to Fabricate Durable Superhydrophobic Coatings for Flexible Electronic Sensors

“…With a high water contact angle (WCA, >150 • ), and a low sliding angle (SA, <10 • ), superhydrophobic surfaces, inspired by natural creatures, have attracted extensive attention in academia [1,2]. Many methods, such as electrospinning [3,4], sol-gel [5][6][7], etching [8][9][10], hydrothermal [11,12], self-assembly [13,14] and template methods [15,16], have been used to prepare superhydrophobic surfaces. With the development of superhydrophobic technology, a single superhydrophobic surface cannot meet our requirements.…”