Superhydrophobic Al Surfaces with Properties of Anticorrosion and Reparability

Abstract

Aluminum (Al) is one of the most widely used metals for industry and household applications, but its longevity is limited by its tendency for corrosion. In this work, we report a facile method to fabricate superhydrophobic Al surfaces that have excellent anti-corrosion effect. The surface is obtained by etching Al in CuCl2 solution to form the micro–nano-pit surface texture followed by lowering its surface energy in an aqueous ethanol solution of stearic acid. The superhydrophobic Al surfaces show water contact angles as high as 165°. Electrochemical tests demonstrate that the corrosion rate of the Al surface drops by 94.5% after the superhydrophobic modification (corrosion current density lowers from 1.11 × 10–4 to 6.10 × 10–6 A cm–2). We also show that the superhydrophobic surface will protect the Al from corrosion even under a very harsh environment. In addition, our method is scalable and the superhydrophobic surfaces exhibit excellent flexible and reparable properties. This anti-corrosive superhydrophobic Al surface will prolong Al in its broad usage.

Easy and Fast Fabrication of Self-Cleaning and Anti-Icing Perfluoroalkyl Silane Film on Aluminium

“…Low adhesion of the superhydrophobic surface allows droplets to roll off quite easily and get rid of various external contaminants, just like the natural lotus leaf, according to the mechanism schematically presented in Figure 10. This behaviour has been theoretically explained by the Cassie and Baxter equation [5,28,37].…”

“…Chemical etching of aluminium has been reported in several studies (e.g., [21]); usually, it is performed in strong acid solutions (e.g., HCl, H 2 SO 4 ) in combination with other reagents such as HCl/H 2 O 2 [22], HCl/HF-Beck's solution [23][24][25] or alkaline solutions (e.g., NaOH) [9,26]. The surface etching process can be performed also in solutions of metal chlorides such as NaCl [25], CuCl 2 [27,28], and FeCl 3 [21,27,29,30]. A comparative study of various etchants confirms that the best performance was obtained with FeCl 3 [27].…”

Relationship and Interconversion Between Superhydrophilicity, Underwater Superoleophilicity, Underwater Superaerophilicity, Superhydrophobicity, Underwater Superoleophobicity, and Underwater Superaerophobicity: A Mini-Review

“…As three common states of matter, solid, liquid, and gas form different kinds of solid/liquid/gas interfaces. The materials with extreme wettability have received increasing attention because of their wide practical applications in waterproof coating (Yong et al, 2017c ), anti-icing/snowing/fogging (Lv et al, 2014 ; Kreder et al, 2016 ; Chu et al, 2019 ), self-cleaning coating (Nishimoto and Bhushan, 2013 ; Yong et al, 2013c , 2014b ; Ragesh et al, 2014 ), the manipulation of small droplets (Wang et al, 2011 ; Yong et al, 2013b , 2015b ), corrosion resistance (Pan et al, 2013 ; Zhan et al, 2018 ), oil/water separation (Xue et al, 2014 ; Wang B. et al, 2015 ; Yong et al, 2016a , b , 2018e , 2019c ; Bian et al, 2020 ), fog collection (Zhang et al, 2017 ), cell engineering (Stratakis et al, 2011 ; Shen et al, 2012 ), anti-biological adhesion (Genzer and Efimenko, 2006 ; Yong et al, 2018f ), drag reduction in water (Shi et al, 2007 ), lab on a chip (Kwon et al, 2007 ; Vitale et al, 2013 ), microfluidic system (Songok et al, 2014 ; Wang S. et al, 2015 ), liquid patterning (Jokinen et al, 2008 ; Yong et al, 2015c ), enhanced buoyancy (Yong et al, 2014c ; Zhan et al, 2019 ), submarine gas collection (Yong et al, 2018c , d ). After billions of years of evolution, creatures in nature have nearly perfect structure and function.…”

Underwater superpolymphobicity: Concept, achievement, and applications

“…In the past 2 decades, the materials with great repellence to water, oils (in air or underwater), or underwater bubbles have always been one of the research focuses because they have wide applications in liquid-repellent surfaces, [1,2] self-cleaning, [3][4][5] anti-fogging/snowing/icing, [6][7][8] droplet manipulation, [9][10][11] anticorrosion, [12,13] cell engineering, [14][15][16][17] oil/water separation, [18][19][20][21][22][23][24] lab chip, [25][26][27][28] submarine drag reduction, [29] water harvesting, [30] gas collection, [31,32] enhanced buoyancy, [33,34] liquid patterning, [35,36] and so on. Various superwettabilities the composition of liquid polymers (LPs) is more complex, and the LPs usually have the features of low fluidity and high viscosity.…”