Robust and superhydrophobic coating highly resistant to wear and efficient in water/oil separation

Abstract

Here, we report a straightforward and rapid process using fatty acids to produce a stable superhydrophobic hybrid composite coating on aluminium substrate which is highly resistant to wear under environmental conditions. Furthermore, this novel superhydrophobic metal surface is highly efficient at separating of water/oil systems. The single-step process we adopt involves electrochemical deposition of ZnCl2, α-Al2O3 and lauric acid (C11H23COOH) onto commercial pure aluminium substrate. The resultant static contact angle (170°) and sliding angle (1°) are those of a superhydrophobic coating with self-cleaning properties; while chemical analysis shows that this is the result of generation of zinc laurate (Zn(C11H20COO)2) as a major compound that increases the superhydrophobic character of the coating, generating a flower-like structure 70 nm thick. Different wear tests show the coating is resistant to severe conditions, confirming its real potential against weathering, including sand and 2 water erosion. Finally, a water/oil separation test determined 99% separation efficiency in hexane and ether petroleum systems, in a laboratory-made storage tank.

Electrophoretic‐deposited Superhydrophobic Coatings

“…A composite coated (ZnCl 2 +α‐Al 2 O 3 +lauric acid) tank displayed high efficiencies of 98.4% and 99.7% for separating hexane and petroleum ether, respectively. The Cθ measured after 15 separation cycles was 153±0.62° [104,149] …”

Preparation and Performance Test of the Super-Hydrophobic Polyurethane Coating Based on Waste Cooking Oil

“…In view of the poor mechanical durability of super-hydrophobic surfaces, some super-hydrophobic coatings with nanoparticles and polymers have been proposed in recent years [30]. Nanoparticles such as SiO 2 [31], ZnO [32], TiO 2 [30] and Al 2 O 3 [33] are often used to manufacture super-hydrophobic coatings. Achieving efficient dispersion of the filler in the polymer matrix is a very important task because filler particles, especially nano-sized filler particles, tend to aggregate due to their high surface energy [34].…”

Biomimetic superhydrophobic metal/nonmetal surface manufactured by etching methods: A mini review

“…Bionic materials are materials prepared by simulating the unique structure or characteristics of organisms (Suresh Kumar et al, 2020;Koch et al, 2008). Biomimetic superhydrophobic surfaces, which are prepared by using the superhydrophobic phenomena related to biological structures in nature (Table 1), such as lotus leaves (Sun and Guo, 2019;Lv et al, 2020), butterfly wings (Zheng et al, 2007;Shao et al, 2019) and rice leaves (Wu et al, 2011;Lee et al, 2013;Rius-Ayra et al, 2018), have attracted wide attention and research because of outstanding self-cleaning (Barthlott and Neinhuis, 1997;Fürstner et al, 2005;Ming et al, 2005), anti-icing (Liu et al, 2020;Sun et al, 2020), anti-corrosion (Liu et al, 2014;Wei et al, 2021a;Zhang et al, 2022), and oil-water separation (Wang et al, 2015a;Saleh et al, 2020;Rasouli et al, 2021;Yao et al, 2021) properties. In recent years, with the deepening of the research in the micro-field, micro-nano materials have developed rapidly, and they have been developed into intelligent responsiveness (Li et al, 2017a;Chang et al, 2018;Li et al, 2021a), environmental remediation (Kumari et al, 2019;Sajjadi et al, 2021), biodegradability (Li et al, 2021b;Li et al, 2022a;Li et al, 2022b), nano-probe imaging (Li et al, 2016;Li et al, 2017b;Li et al, 2019a;Li et al, 2022c), and other characteristics, which are widely used in many fields (Waked, 2011;Khandelwal et al, 2016;…”