Facile Fabrication of High‐White and Robust Superhydrophobic Ni/Al₂O₃ Composite Coating on Al Alloy

Abstract

This work presented a facile method to fabricate high‐white and robust superhydrophobic film on Al alloy surface. Ni/Al2O3 film with appropriate roughness and high‐white surface were constructed on the Al alloy by a simple chemical bath method via placing the Al alloy into the Ni2+ aqueous solution. Then the surface energy was reduced by spin‐coating the stearic acid (STA) to achieve excellent superhydrophobicity. As expected, the reflectivity, self‐cleaning, corrosion resistivity and mechanical durability of Al alloy after modification have all displayed dramatic enhancements. The reflectance of the modified Al alloy is far above the pristine Al alloy at all wavelengths (200‐2000 nm). This high‐white film with remarkable reflectivity can effectively reduce its surface temperature and improve visibility in practical application. Finally, a champion water contact angle of 161° and corrosion resistivity of 97.6% were attained by coating Ni/Al2O3‐STA composite film on Al alloy. The Leeb hardness of superhydrophobic film coated Al alloy was enhanced from 325 to 461 after coating superhydrophobic film on Al alloy. This work provides a framework for the development of superhydrophobic Al alloy with high‐whiteness and robustness.This article is protected by copyright. All rights reserved.

Mechanically Durable and Fluorine‐Free Ni–Cr Alloy‐Based Highly Hard Superhydrophobic Coating on Al Alloy

“…Figure 4D–F shows the high‐resolution XPS spectra of Ni, Cr, and C. In Figure 4D, the peaks at a binding energy of 852.9, 856.2, 861.4, 870.2, and 873.7 eV were assigned to Ni 2 p 3/2 metallic Ni, the Ni 2 p 3/2 oxidized state of Ni, Ni 2 p 3/2 satellite peak, Ni 2 p 1/2 metallic Ni, and the Ni 2 p 1/2 oxidized state of Ni, respectively. [ 2,8,32 ] In Figure 4E, the peaks at 587.2, 577.6, and 574.4 eV can be attributed to Cr 2 p 1/2 oxidized state, Cr 2 p 3/2 oxidized state, and Cr 2 p 3/2 metallic Cr. [ 33–36 ] As displayed in Figure 4F, the peaks at binding energy of 288.6 and 286.5 eV in the C 1 s spectrum can be correlated with the –COOH group in STA and the bond of C─O, while the peak at 284.8 eV for C was applied as the standard peak for calibration.…”

“…[ 5–7 ] To address this issue, superhydrophobic coatings have emerged as a potential solution, offering robust water‐repellent characteristics and limited interaction with salt solutions. [ 8–10 ] Beyond their ability to mitigate corrosion, superhydrophobic coatings offer advantages such as self‐cleaning, antifouling, low maintenance requirements, antiadhesion, and anti‐icing properties. [ 11–13 ] Despite the promise of superhydrophobic coatings, a significant research gap exists in addressing their mechanical limitations.…”