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Superhydrophobic nano Cu/Al 2 O 3 Ni–Cr composited coating with a low adhesive force was deposited onto the Q345 carbon steel via electro-brush plating. Surface morphologies of nano Cu/Al 2 O 3 Ni–Cr composited coating were investigated by scanning electron microscope (SEM). Chemical compositions were characterized by energy dispersive spectroscopy (EDS). First of all, by adjusting different process parameters such as working voltage, relative velocity, Cu particles concentration and plating time, we obtain the most optimal parameters: working voltage is 15 V, relative velocity is 4.8 m/min, Cu particles concentration is 5 g/L and plating time is 60 s. Under the best process parameters, the water contact angle reaches to 156° and a sliding angle is less than 2° on the nano Cu/Al 2 O 3 Ni–Cr coating. Then the mechanism of the superhydrophobic and low adhesion characteristic of this surface were explained by Cassie's model. Low adhesive force can be characterized by max rebound height of water droplet. As a result, to achieve low adhesive surface it is necessary to decrease the fraction of the solid/liquid interface under the water droplet. Finally the coating was proved to have an excellent self-cleaning performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Superhydrophobic PLA surface can be prepared by a one-step spraying methods. • The as-prepared PLA fabric can be used for continuous oil-water separation. • The as-prepared PLA fabric can separate oil-water mixtures under harsh environments. • The as-prepared PLA fabric exhibits outstanding environmental and mechanical stability. Various types of functional materials incorporating superhydrophobic components have been rapidly developed for efficient oil/water separation. The post-processing of these used separated materials remains a challenging problem due to their non-biodegradable characteristics in natural environments, thus easily contributing to secondary contamination. Herein, we report a biodegradable superhydrophobic PLA fabric with hierarchical coral-like micro/nano structures by a one-step spraying method. The as-prepared PLA fabric was found to be both superhydrophobic and superoleophilic with a static water contact angle of 161 ± 2° and an oil contact angle of 0°. In addition, the as-prepared PLA nonwoven fabrics also revealed efficient continuous oil separation efficiency (>97.5%) and tiny water droplet collection efficiency, as well as high oil flux ranging from 2239 L·m−2·h−1 to 59,713 L·m−2·h−1. Furthermore, these fabrics retained their inherent wetting property and oil separation ability in a variety of acidic and basic solutions, 3.5 wt% NaCl solution, hot (100 °C), and freezing (0 °C) temperatures. This study provides a novel and environmentally friendly method for preparing biodegradable oil–water separation materials with green post-treatment characteristics when compared to the non-biodegradable separation materials, indicating potential applications in the fields of green water treatment and petroleum refining. [ABSTRACT FROM AUTHOR]

Superhydrophobic surface is of wide application in the field of catalysis, lubrication, waterproof, biomedical materials, etc. The superhydrophobic surface based on hard metal is worth further study due to its advantages of high strength and wear resistance. This paper investigates the fabrication techniques towards superhydrophobic surface on carbon steel substrate via electric corrosion and studies the properties of as-prepared superhydrophobic surface. The hydrophobic properties were characterized by a water sliding angle (SA) and a water contact angle (CA) measured by the Surface tension instrument. A Scanning electron microscope was used to analyze the structure of the corrosion surface. The surface compositions were characterized by an Energy Dispersive Spectrum. The Electrochemical workstation was used to measure its anti-corrosion property. The anti-icing performance was characterized by a steam-freezing test in Environmental testing chamber. The SiC sandpaper and 500 g weight were used to test the friction property. The research result shows that the superhydrophobic surface can be successfully fabricated by electrocorrosion on carbon steel substrate under appropriate process; the contact angle of the as-prepared superhydrophobic surface can be up to 152 ± 0.5°, and the sliding angle is 1–2°; its anti-corrosion property, anti-icing performance and the friction property all show an excellent level. This method provides the possibility of industrialization of superhydrophobic surface based on iron substrate as it can prepare massive superhydrophobic surface quickly. [ABSTRACT FROM AUTHOR]

Highlights • Synthesis of 3D dahlia-like Co 3 O 4 by hydrothermal deposition. • Co 3 O 4 coating has excellent superhydrophobicity after FAS-17 modification. • Unmodified Co 3 O 4 /nickel foam can efficiently separates various oil-water mixtures. • Superhydrophobic Co 3 O 4 /nickel foam can adsorb trichloromethane underwater. • Rapid oil-water separation and collection with different Co 3 O 4 /nickel foam. Abstract The synthesis of nanomaterial on porous materials and use of their porous structure for oil-water separation and oil absorption underwater at normal temperature and pressure are a very significant process, which has attracted wide attention. In this paper, dahlia-like Co 3 O 4 nanoparticles was synthesized on the surface of porous nickel foam by hydrothermal reaction. After modification with heptadecafluoro-1,1,2,2-tetrahydro-decyl-1-trimethoxysilane (FAS-17), the as-prepared sample surface could obtain good oleophobicity and excellent superhydrophobicity with high contact angles and low sliding angles. Furthermore, the as-prepared superhydrophobic composite had low adhesion to water and light oil, and could be subjected to simple and effective oil-water separation (including three light oil and one heavy oil) at normal temperature and pressure. Due to the magnetic properties of nickel foam, underwater oil absorption experiment was carried out by magnetic traction, which could achieve a perfect oil absorption effect. In addition, the comprehensive use of unmodified and modified Co 3 O 4 /nickel foam at the end of tube can quickly and efficiently carry heavy oil (trichloromethane)-water separation and collection. Therefore, the as-prepared dahila-like Co 3 O 4 on nickel foam not only has good application value in oil-water separation, but also has excellent potential in underwater oil absorption. [ABSTRACT FROM AUTHOR]