Abrasion‐Resistant, Hot Water‐Repellent and Self‐Cleaning Superhydrophobic Surfaces Fabricated by Electrophoresis of Nanoparticles in Electrodeposited Sol–Gel Films

Abstract

superhydrophobic surface with fluorinefree chemicals, most of these methods focus on the functionalized nanoparticles (NPs) at strict conditions, e.g., refluxing in toluene containing particles and modifier at N 2 atmosphere. [26][27][28] Therefore, it is still necessary to develop new methods to prepare superhydrophobic NPs at a much more moderate condition.Another severe problem lies in most superhydrophobic surfaces that are prone to be easily damaged by mechanical abrasion and finger touch due to the destruction of fragile microscopic roughness features [29,30] or the loss of low energy surface material, [31] which greatly limits their practical use. Most of the recent works focus on creating mechanically stable superhydrophobic surfaces from the polymeric substrates (like fabric or cotton). [32][33][34][35] Robust superhydrophobic surfaces constructed on hard substrates, however, are still a great challenge. [36] One strategy is to introduce lowsurface-energy polymers in the nanocomposite coating. [37,38] However, consideration still should be taken like the wear resistant ability and thermal stability of the polymer, the compatibility between NPs and polymeric matrix, and the adhesion strength of the polymer to the substrate. [39] Another strategy is to create microscopic roughness from the bulk matrix materials themselves at the surfaces like chemical etching, [40] plasma texturing, [41] laser ablating [42] on metal and its alloy. The comprising part of matrix materials to create the required micro/ nanostructure is destructive to the substrates and the required special and expensive equipment also limits their use.In order to resolve the above-mentioned two problems, in the present work, a much more cost-effective and environmentfriendly synthesis route is developed to generate fluorine-free superhydrophobic NPs (silica particles used as model in this work) at room temperature by using long-chain alkyl organosilane as the low-surface energy modifier. Furthermore, the mechanical durability of the superhydrophobic surfaces is guaranteed by using the electrochemically generated SiO 2 (e-SiO 2 ) films as the robust matrix of the superhydrophobic NPs. The superhydrophobic SiO 2 (SH-SiO 2 ) nanoparticles are deposited into highly porous e-SiO 2 films by electrophoresis. The proofof-concept is shown in Figure 1. The robust structure of e-SiO 2 film is ensured by the production of OH − ion catalyst near the electrode surface, i.e. the additional driving force for film growth, when applying cathodic potentials. [43] And the high porosity is a result of the separation of gelation process from The present work reports on a new strategy for fabrication of mechanically stable and environmental-friendly superhydrophobic surfaces. First, a novel cost-effective approach is developed to synthesize superhydrophobic SiO 2 (SH-SiO 2 ) nanoparticles at room temperature through the reaction between the surface reactive groups on commercial SiO 2 nanoparticles and the longchain alkyl fluorine-free organosilane. Then, the superh...

Organic carbon dot coating for superhydrophobic aluminum alloy surfaces

“…[17][18][19] In addition, ZnO, TiO 2 , and SiO 2 are widely used during the creation of the rough structure, which may threaten human health. [20][21][22] Therefore, eco-friendly materials are highly desired to fabricate superhydrophobic surfaces. Recently, as a new carbon nanomaterial, carbon dots (CDs) have attracted considerable attention owing to their nanometer size, good biocompatibility, low toxicity, excellent optical properties, and high photostabil-ity.…”

“… 17 – 19 In addition, ZnO, TiO 2 , and SiO 2 are widely used during the creation of the rough structure, which may threaten human health. 20 – 22 …”

One-step fabrication of robust superhydrophobic and superoleophilic surfaces with self-cleaning and oil/water separation function

“…Over the last few decades, superhydrophobic surfaces have attracted considerable attention due to their diverse practical applications, such as self-cleaning 1 , oil/water separation 2 , corrosion resistance 3 , anti-icing 4 , anti-fogging 5 , anti-fouling 6 , anti-bacterial 7 , anti-reflection 8 , and drag reduction 9 . Many functional biological surfaces in nature, including lotus leaves 10 , rose petals 11 , butterfly wings 12 , and water striders 13 , among others 14 , possess unique wettability properties.…”

Topography‐Directed Hot‐Water Super‐Repellent Surfaces

“…Previous studies have mainly been focused on the fabrication of hot-water super-repellent surfaces, such as by spray coating, deposition, and electrophoresis-assisted coating, and their applications for self-cleaning and oil/water separation, [7][8][9][10][11][12][13][14][15] whereas only a few studies have reported on wetting mechanisms by hot water. Despite its importance, the effort to study the mechanisms of super-repellency to hot liquids appears very limited.…”

“…Previous studies have mainly been focused on the fabrication of hot-water super-repellent surfaces, such as by spray coating, deposition, and electrophoresis-assisted coating, and their applications for self-cleaning and oil/water separation, [7][8][9][10][11][12][13][14][15] whereas only a few studies have reported on wetting mechanisms by hot water. Previous studies have mainly been focused on the fabrication of hot-water super-repellent surfaces, such as by spray coating, deposition, and electrophoresis-assisted coating, and their applications for self-cleaning and oil/water separation, [7][8][9][10][11][12][13][14][15] whereas only a few studies have reported on wetting mechanisms by hot water.…”