Oily water treatment has attracted the attention of many researchers. The development of effective and cheap oil/water separation materials is urgent for treating this problem. Herein, inspired by superhydrophobic typical plant leaves such as lotus, red rose and marigold, superhydrophobic and superoleophilic copper mesh was fabricated by etching and then surface modification with 1-dodecanethiol (HS(CH2)11CH3). A rough silver layer is formed on the mesh surface after immersion. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity and the static water contact angle was 153° ± 3°. In addition, the as-prepared copper mesh shows self-cleaning character with water and chemical stability. The as-prepared copper foam can easily remove the organic solvents either on water or underwater. We demonstrate that by using the as-prepared mesh, oils can be absorbed and separated, and that high separation efficiencies of larger than 92% are retained for various oils. Thus, such superhydrophobic and superoleophilic copper mesh is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment.

A novel pH-responsive smart device has been developed for continuous separation of oil/water mixtures. Smart surfaces are obtained by electroless silver deposition followed by surface modification with a mixed solution of thiol containing carboxylic groups and methyl groups (HS(CH2)11CH3 and HS(CH2)10COOH). It was found that the wettability of the as-prepared copper foams can switch reversibly between superhydrophobicity and hydrophilicity according to their pH response. The as-prepared copper foam can easily remove the organic solvents either on water or underwater. Furthermore, the as-prepared copper foams can be applied to separate an oil-and-water mixture bidirectionally with high efficiency. This study provides a simple and environmentally friendly route to fabricate oil–water separation materials which have potential applications in industrial fields, such as in water treatment and petroleum refining. In particular, this smart surface is switchable under various pH conditions.

Superamphiphobic (both superhydrophobic and superoleophobic) surfaces have attracted great interests in the fundamental research and practical application. This research successfully fabricated the superamphiphobic surfaces by combining the nickel plating process and modification with perfluorocaprylic acid. The cooperation of hierarchical micro-nano structures and perfluorocaprylic acid with low surface energy plays an important role in the formation of superamphiphobic surfaces. The contact angles of water/oil have reached up to 160.2 ± 1°/152.4 ± 1°, respectively. Contrast with bare substrate, the electrochemical measurements of superamphiphobic surfaces, not only the EIS measurement, but also potentiodynamic polarization curves, all revealed that, the surface corrosion inhibition was improved significantly. Moreover, superamphiphobic surfaces exhibited superior stability in the solutions with a large pH range, also could maintain excellent performance after storing for a long time in the air. This method is easy, feasible and effective, and could be used to fabricate large-area mutli-functional surface. Such a technique will develop a new approach to fabricate superamphiphobic surfaces on different engineering materials.

•We have prepared a biomimetic super-hydrophobic surface on copper substrate by one-step electrodeposition.•The super-hydrophobicity mechanism relies on morphologies and chemical component on surface.•The super-hydrophobic surface has a good corrosion inhibition.Inspired by the special microstructure of plant leaves such as lotus leaves, we prepared super-hydrophobic surfaces by a fast, facile, and one-step electrodeposition on copper substrates. The prepared surface revealed super-hydrophobicity with a contact angle value of 161.5° ± 2°. Meanwhile, corrosion resistance of obtained coatings was evaluated by electrochemical measurement in detail. These results indicated that electrodeposition coatings provided greater protection against corrosion behavior. Moreover, the super-hydrophobicity improved corrosion resistance of the coating. This method can be easily extended to other conductive materials and time-saving, having a great potential for future application in industrial fields.

•We have prepared a super-hydrophobic surface on copper substrate by one-step anodization process.•The super-hydrophobicity mechanism relies on morphologies and chemical component on surface.•The super-hydrophobic surface has an excellent anticorrosion.Inspired by the microstructures of typical plants’ leaf surface, such as lotus leaves, red rose petals, rice leaves, etc. a functional superhydrophobic surface of aluminum alloy has been successfully fabricated by the one-step anodization process. The as-prepared superhydrophobic surface has a high contact angle of 171.9° ± 2° and a low tilting angle of 6.2° ± 1°, and possesses a good long-term stability. In addition, the resulting surfaces exhibit excellent anticorrosion and self-cleaning properties. The surface morphologies, chemical composition, wettability, corrosion resistance were characterized by means of scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle measurements, and electrochemical workstation. This study provides a simple, low-cost and effective route to fabricate large-area superhydrophobic surface with corrosion resistance and self-cleaning for a great number of potential applications, and can be easily extended to other metal materials.

Super-hydrophobic surface has many special functions that are studied wildly. The ingenious microstructures of typical plant leaves with super-hydrophobicity enlighten researchers to design and fabricate artificial super-hydrophobic surface. Being the lightest alloy among structural metals materials magnesium alloy was restricted due to its poor corrosion resistance. A super-hydrophobic surface with self-cleaning was successfully deposited on AZ91D magnesium alloy by the nickel plating process. The super-hydrophobic surfaces were covered with cauliflower-like cluster binary micro-nano structural Ni coatings. The procedure was that the samples were processed by plating after pretreatment, finally modified by stearic acid (CH3(CH2)16COOH). The surface morphologies, chemical composition, wettability and corrosion resistance are characterized by means of SEM, FT-IR, water contact angle and electrochemical impedance spectroscopy (EIS) measurements. The as-prepared super-hydrophobic surface has a contact angle as high as 160.8 ± 1° and a SA as low as 1.8 ± 1°, showing good long-term stability. The super-hydrophobic surface exhibited excellent corrosion resistance property in the 3.5 wt. % NaCl solution. This method could provide a straightforward and effective route to fabricate large-area super-hydrophobic surface with anticorrosion and self-cleaning for a great number of potential applications, and easily extended to other metal materials.

A superhydrophobic graphene film with excellent mechanical abrasion resistance and corrosion resistance was successfully deposited on Al alloy using a spin-coating method. The surface structure morphology, chemical composition, wettability, mechanical abrasion and corrosion resistance were characterized by scanning electron microscopy, atomic force microscopy (AFM), Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, water contact angle measurements, wear tester and electrochemical workstation. It was found that the static water contact angle on the as-prepared surface was as high as 153.7 ± 2°. Furthermore, the as-prepared surface exhibited excellent mechanical abrasion resistance and corrosion resistance, which were studied by Tafel curve and electrochemical impedance spectroscopy (EIS). It is expected that this simple and versatile methodology for preparing a graphene-reinforced coating can open up a new avenue, especially for multi-functional engineering materials, and be conveniently extended to other metal substrates.

Triggered by the microstructure characteristics of the surfaces of typical plant leaves such as the petals of red roses, a biomimetic superhydrophobic surface with high adhesion is successfully fabricated on aluminum alloy. The essential procedure is that samples were processed by a laser, then immersed and etched in nitric acid and copper nitrate, and finally modified by DTS (CH3(CH2)11Si(OCH3)3). The obtained surfaces exhibit a binary structure consisting of microscale crater-like pits and nanoscale reticula. The superhydrophobicity can be simultaneously affected by the micronano binary structure and chemical composition of the surface. The contact angle of the superhydrophobic surface reaches up to 158.8 ± 2°. Especially, the surface with micronano binary structure is revealed to be an excellent adhesive property with petal-effect. Moreover, the superhydrophobic surfaces show excellent stability in aqueous solution with a large pH range and after being exposed long-term in air. In this way, the multifunctional biomimetic structural surface of the aluminum alloy is fabricated. Furthermore, the preparation technology in this article provides a new route for other metal materials.Keywords: adhesion; aluminum alloy; biomimetic; chemical etching; laser processing; superhydrophobicity;

The hydrophobic coating has been a promising technology for improving surface performance. The surface performance of magnesium alloy has been limited in application. Furthermore, the hydrophobic of magnesium alloy is rarely investigated because magnesium alloy is an active metal alloy. In this paper, inspired by microstructure character of typical plant leaf surface such as lotus, the biomimetic hydrophobic coatings on AZ91D magnesium alloy surface were prepared by means of wet-chemical combining electroless. The samples were immersed into AgNO3 solution in wet-chemical method firstly. Then, biomimetic hydrophobic coatings were prepared by electroless after wet-method pretreatment. The microstructure was observed by SEM and the contact angles were measured by contact angle tester. The results indicated that the biomimetic hydrophobic coatings with uniform crystalline and dense structure could be obtained on AZ91D magnesium alloy surface. The results of contact angle revealed that the biomimetic nano-composite coatings were hydrophobic. The wet-chemical method treatment on the AZ91D magnesium alloy substrate provided a rough microstructure, thus improving adhesion of the coating and the substrate.

A facile, rapid and one-step electrodeposition process has been employed to construct a superhydrophobic surface with micro/nano scale structure on a Mg-Sn-Zn (TZ51) alloy, which is expected to be applied as a biodegradable biomedical implant materials. By changing the electrodeposition time, the maximum contact angle of the droplet was observed as high as 160.4° ± 0.7°. The characteristics of the as-prepared surface were conducted by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). Besides, the anti-corrosion performance of the coatings in stimulated body fluid (SBF) solution were investigated by electrochemical measurement. The results demonstrated that the anti-corrosion property of superhydrophobic surface was greatly improved. This method show beneficial effects on the wettability and corrosion behavior, and therefore provides a efficient route to mitigate the undesirable rapid corrosion of magnesium alloy in favor of application for clinical field.

A novel pH-responsive smart device has been developed for continuous separation of oil/water mixtures. Smart surfaces are obtained by electroless silver deposition followed by surface modification with a mixed solution of thiol containing carboxylic groups and methyl groups (HS(CH2)11CH3 and HS(CH2)10COOH). It was found that the wettability of the as-prepared copper foams can switch reversibly between superhydrophobicity and hydrophilicity according to their pH response. The as-prepared copper foam can easily remove the organic solvents either on water or underwater. Furthermore, the as-prepared copper foams can be applied to separate an oil-and-water mixture bidirectionally with high efficiency. This study provides a simple and environmentally friendly route to fabricate oil–water separation materials which have potential applications in industrial fields, such as in water treatment and petroleum refining. In particular, this smart surface is switchable under various pH conditions.