The adhesion behaviors of superhydrophobic surfaces have become an emerging topic to researchers in various fields as a vital step in the interactions between materials and organisms/materials. Controlling the chemical compositions and topological structures via various methods or technologies is essential to fabricate and modulate different adhesion properties, such as low-adhesion, high-adhesion and anisotropic adhesion on superhydrophobic surfaces. We summarize the recent developments in both natural superhydrophobic surfaces and artificial superhydrophobic surfaces with various adhesions and also pay attention to superhydrophobic surfaces switching between low- and high-adhesion. The methods to regulate or translate the adhesion of superhydrophobic surfaces can be considered from two perspectives. One is to control the chemical composition and change the surface geometric structure on the surfaces, respectively or simultaneously. The other is to provide external stimulations to induce transitions, which is the most common method for obtaining switchable adhesions. Additionally, adhesion behaviors on solid-solid interfaces, such as the behaviors of cells, bacteria, biomolecules and icing on superhydrophobic surfaces are also noticeable and controversial. This review is aimed at giving a brief and crucial overview of adhesion behaviors on superhydrophobic surfaces.

The lotus leaf is known as one of the natural self-cleaning plants, which can easily roll off water but not oil droplets. Herein, a simple chemical bath deposition method to fabricate superhydrophobic and strong oleophobic surfaces was presented on porous substrates such as fabrics and nickel foams. The resultant substrates exhibited excellent superhydrophobicity and good oil repellency. More significantly, such surfaces possessed self-cleaning property for water, as well as to oils such as glycerol and rapeseed oil.In nature, many surfaces are superhydrophobic with water contact angles larger than 150°and sliding angles lower than 10°. Lotus leaves, rice leaves, and cicada wings are some representative surfaces with superhydrophobic properties, which generally represent in the form of self-cleaning.1 However, such a self-cleaning effect will be deteriorated by various degrees when the surface is contaminated by oily waste liquids in practical applications. 2 Although superoleophobicity has been found in the case of fish scale and shark skin in nature, such oil repellency exists only underwater. There are very few reports on oil repellency in air, 3 because the lower surface tension of oil makes the lyophobicity harder achieve than in the case of water. 4 Therefore, it is urgent, necessary, and challenging to design and fabricate superhydrophobic surfaces with antioily contamination for industrial applications.To achieve these properties, improving the oleophobicity of superhydrophobic surfaces is of utmost significance. It is well known that wettability is governed by both the chemical composition and geometric structure of a solid surface. 5According to three models that describe the contact angle of a droplet on a surface, 68 lower surface energy and proper roughness are necessary for achieving superoleophobic surface. In general, some special structures such as a re-entrant or overhanging geometries are indispensable to obtain appropriate roughness for superoleophobicity. 911 Besides, fluorinated chemicals with extremely low surface energies, such as perfluoroalkylthiol and perfluorinated silane, are also essential to obtain a superoleophobic surface. So far, only a few of methods have been developed to fabricate both superhydrophobic and superoleophobic surfaces (also called superamphiphobic) on various substrates, including electrochemical method, 12 electrodeposition, 13 and so on. 1416 Superoleophobic surface on a metal substrate has been widely reported because of the facile construction of roughness by chemical etching and deposition. 17Superoleophobic fabrics have also been prepared by using the multiscale structure concept. 18 Moreover, a self-healing superamphiphobic surface has been obtained by coating the fluorocontaining polymers on the fabric.19 Compared to the conventional superhydrophobic surface, 2023 these as-prepared surfaces with superhydrophobictiy and strong oleophobicity are exciting since a great progress has been made on lowering the surface free energy and constructing more fine su...

It is well known that superhydrophobic surfaces with unitary microstructures (such as the lotus leaf) have better surface mechanical properties than those with binary micro-and nanostructures (such as the ramee leaf). Rodlike unitary structured films are fabricated on copper meshes via a facile and simple chemical vapor corrosion method. Following the surface modification of 1-decanethiol (C 10 H 22 S), the resultant films exhibiting superhydrophobicity and superoleophilicity can be applied to separate the oilwater mixture.In recent years, with the development of extreme wettability, more potential applications based on it are explored, including anti-icing, antifogging, water-collecting, and antifouling applications.1 Oilwater separation has led to wide concerns since Jiang et al.2 first reported an example to separate oil from water by using superhydrophobic and superoleophilic Tefloncoated meshes. Henceforth, many porous substrates such as metallic mesh films, 3 foams, 4 textiles, 5 filter papers, 6 and sponges 7 have become popular to achieve oilwater separation by combining rough morphology with low-surface-energy compounds. Various methods have been employed to fabricate diverse rough morphologies. 812 For example, Jiang et al. 11constructed aligned ZnO nanorod array on a stainless steel mesh with photoinduced oilwater separation via a two-step solution-growth approach. Based on a solgel method, Miyake et al. 12 prepared a TiO 2 film composed of uniform fine grains on the Ti mesh, exhibiting underwater superoleophobicity after UV irradiation, to be applicable as an oilwater separation filter. Our group 13,14 have also made efforts to separate oil and water. Inspired from the butterfly wing, we fabricated superhydrophobic copper mesh films by electroplating Cu nanoparticles on the as-cleaned copper mesh films, followed by thiol grafting. The fabricated films showed efficient and rapid oilwater separation ability and could be used for numerous times. Moreover, we further achieved pH-responsive bidirectional oilwater separation by modifying a thiol mixture of HS(CH 2 ) 9 CH 3 and HS(CH 2 ) 10 COOH on hierarchical copper wires coated with Cu nanoparticles.14 Importantly, in our previous research, 15 we found that the surface mechanical properties of superhydrophobic surfaces with unitary microstructures are better than the surfaces with binary micro-and nanostructures. It is still a challenge for us to fabricate biomimetic superhydrophobic surfaces with good mechanical properties because it is very important for them to be applied in industry.Recently, many superhydrophobic surfaces have been applied to separate oilwater mixtures and the metal meshes such as copper mesh were widely used to fabricate the superhydrophobic surfaces for such separations. However, most of the methods are time-consuming and complicated. Herein, a facile chemical vapor corrosion method is employed to fabricate a unitary microstructured Cu(OH) 2 film. Combined with the surface modification of 1-decanethiol (C 10 H 22 S) to reduce the...