Through the reasonable design of the microstructure of superhydrophobic coatings, the solid-liquid contact area between the substrate and the liquid can be reduced, the penetration of corrosive medium into the liquid can be reduced, and the flow resistance can be lowered. In this paper, a bionic superhydrophobic composite coating of aluminum matrix material was prepared by the spraying method using KH550 coupling agent-modified silica (KH550@SiO 2 ) and stearic acid-modified titanium dioxide (STA@TiO 2 ) mixed with waterborne polyurethane . The performance was tested by water contact angle , drag reduction measurements, and electrochemical analysis . The composite coating has a droplet contact angle of 163.4° and a rolling angle of 4° and is extremely wettable. The synergistic effect of the air layer and coating densities resulted in excellent corrosion inhibition efficiency of the coating in a 3.5 wt % NaCl solution. In addition, the composite-coated spheres can form a continuous air cavity during water ingress, which is essential for extending the drag reduction capability of the coating in liquids. The design and preparation of superhydrophobic composite coatings have promising applications in large-area corrosion protection and voyage damping of metals.
Aluminum (Al)-based materials composited of different low melting point materials were prepared by mechanical ball-milling. Hydrogen production using these materials was investigated to help resolving the safety issues associated with the storage and transportation of hydrogen. The phase composition and microstructure of the Al-based composited materials were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. As observed in this study, the addition of low melting point metals (such as Sn, Bi and In) helped to lower the initial Al-water reaction temperature and to increase the yield in the production of hydrogen. Samples of optimized compositions, Al–6% Sn–4% Bi and Al–6% Sn–4% In, were found to exhibit high hydrogen production yields of up to 448 and 515 mL, respectively. Meanwhile, their hydrogen generation rates were increased.
Di Zhang,Ruirui Zhao,Guolong Li,Kai Yue,Jingyuan Zhao,Songnan Zhang
Icing is a natural phenomenon, and it is unavoidable, leading to severe economic issues and endangering life safety, especially icing over the aircraft fuselage. Hence, it is highly desirable to adopt effective method to address it. Wherein, the construction and modification of hydrophobic coating is a promising way. In this study, the aluminum-based photothermal/electrothermal composite hydrophobic coating with excellent performance was fabricated by facile spraying of epoxy resin, graphene, polydimethylsiloxane and gaseous nano-silica over etching Al. This coating displayed excellent hydrophobicity, with a water contact angle of 137.4°, which effectively delayed the freezing time of droplets on the cold platform at −10 °C to 360 s. Notably, the superior electrothermal performance enabled the temperature to reach to ca. 80 °C at the voltage of only 1.8 V, melting the ice particle in 164 s and the ice layer with 3 mm thickness in 360 s under the voltage of 1.5 V. Besides, at 1 sunlight intensity, the photothermal effect realized the surface temperature of ca. 45 °C, and the ice layer with 3 mm thickness was melted within 460 s. The multi-effect deicing coating also exhibited excellent photothermal/electrothermal stability and self-cleaning ability. These findings raise new possibilities for the design and development of metal substrate anti-icing/deicing functional coating material.
A highly stable solvate ionic liquid comprising a 2:1 (mol/mol) mixture of ethylene carbonate (EC) and AlCl 3 was used for near room-temperature electrochemical codeposition of an Al-Nd alloy using chlorides as precursors. This liquid is low-cost, easy to prepare, and has high electrochemical stability. The ionic structure was analyzed by 27 Al nuclear magnetic resonance; Raman spectroscopy and the dissolution phenomenon was studied by ultraviolet-visible spectroscopy. The dissolution mechanism of NdCl 3 in this solvate ionic liquid was derived as 3[AlCl 2 (EC) n ] + + 2NdCl 3 ⇆ 2Nd(III) + 3[AlCl 4 ] − + 3 n EC. Cyclic voltammetry was used to explore the electrochemical behavior of Nd- and Al-containing species, revealing that the reduction of Al and Nd are both one-step electron-gaining processes. X-ray diffraction confirmed that an Al-Nd alloy can be obtained in the form of thermally stable Al 2 Nd by potentiostatic electrolysis at high cathode overpotential (− 3.5 V vs. Al). Although the deposited alloy layer is not dense, Al-containing solvate ILs have immense potential in green electrometallurgy because of their higher tunability and similar properties to ILs.
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