Fabrication and anti‐corrosion property of superhydrophobic hybrid film on copper surface and its formation mechanism

Compact and uniform superhydrophobic films were prepared on copper substrates using one‐step solution‐immersion process, and the appropriate preparation conditions were selected for mixed solutions. SEM shows that the hybrid film of 1‐dodecanethiol and tetradecanoic acid on copper substrate is more compact with the contact angle of 160°. The electrochemical impedance spectroscopy and polarization test demonstrate that the anti‐corrosion property of surface‐modified copper substrate is greatly improved, especially for the hybrid film. Moreover, the competitive adsorption process and adsorptive geometry of hybrid film were well explained based on the results of quantum chemistry calculations, SEM, and energy dispersive X‐ray analysis. Copyright © 2009 John Wiley & Sons, Ltd.     

One‐step immersion method for fabricating superhydrophobic aluminum alloy with excellent corrosion resistance

This work develops a facile one‐step immersion method for preparing the superhydrophobic aluminum alloy, i.e. the aluminum alloy is treated with stearic acid (STA)–ethanol–H₂O solution at 60 °C for 35 h. Results show that the aluminum alloy achieves flower‐like structure with both a great deal of pillars and pores, while the long hydrophobic alkyl chains are chemically grafted onto the hierarchical surface. Meanwhile, the water contact angle at the aluminum alloy surface gradually enhances with the decrease of the ethanol–H₂O volume ratio, and the water contact angle and rolling angle of 156.2° and 5°, respectively, are obtained when the ethanol–H₂O volume ratio is 1:3. Moreover, results show that the higher water contact angle at the aluminum alloy, the better corrosion resistance of the aluminum alloy. Consequently, the aluminum alloy with the superhydrophobic property has the best corrosion resistance, durability, and stability in corrosive environments. Copyright © 2016 John Wiley & Sons, Ltd.     

Hierarchical structure microspheres of PCL block copolymers via electrospraying as coatings for fabric with mechanical durability and self‐cleaning ability

The various morphology and structure microspheres were fabricated via one‐step single‐solvent electrospraying of hydrophilic and hydrophobic block modified copolymer of polycaprolactone (PCL). A honeycomb‐like hierarchical structure microspheres of PCL‐b‐PTFOA(4h) and abundant nanometer pores of PCL‐b‐PEG400 microspheres were obtained due to the solvent evaporation, thermally and polymer diffusion‐induced phase separation effect. Furthermore, a superhydrophobic coatings and robust superhydrophobic‐coated cotton woven fabric surfaces were prepared by using PCL‐b‐PTFOA(4h) microspheres with hierarchical structure and low surface energy. The contact angle (CA) and sliding angle (SA) of PCL‐b‐PTFOA(4h) microspheres‐coated cotton woven fabric surfaces reached 164.4 ± 5.5° and 6.8 ± 0.5°, respectively, which allows for self‐cleaning. The self‐cleaning test demonstrated that the coated superhydrophobic surface could shed aqueous dyes and dust without any trace. The superhydrophobic‐coated fabric shows good soaping fastness against mechanical abrasion without significant reduction of CA. This electrospraying coating of block copolymers can provide a simple, facile, and promising technique for producing multifunctional textiles.     

Exploiting carbon‐based (Cr,Ce)/a‐C:H nanocomposite film on cemented WC

Cemented tungsten carbide (WC) has widely served in modern industry because of its outstanding characteristics, while it could suffer from severely wear both under ambient air and water environments. To exploit a novel carbon‐based film should be a feasible way to modify the surface of cemented WC and overcome these shortcomings. In the present study, the Cr/Ce co‐incorporated (Cr,Ce)/a‐C:H carbon‐based film was successfully deposited on cemented WC. The microstructure and mechanical properties of films were systematically characterized, and their tribological behaviors were tested in ambient air and deionized water environment. The results showed that (Cr,Ce)/a‐C:H film dominated by the typical amorphous structure and the doping Cr existed with the metallic Cr nanocrystallites as well as Ce formed CeO₂. The (Cr,Ce)/a‐C:H film could possess good mechanical performances, which could own higher hardness, elastic module, low internal stress, and better adhesive strength. Especially, the as‐prepared (Cr,Ce)/a‐C:H film could present relatively lower friction coefficient and wear rate compared to uncoated cemented WC both under ambient air and deionized water environment, indicating that the Cr/Ce co‐doped (Cr,Ce)/a‐C:H film could be an effective method to modify the surface of cemented WC so as to improve the friction and wear performances of cemented WC materials.     

One‐step electrodeposition of amorphous carbon films containing WO3 with high conductivity and good wettability

Tungsten trioxide‐incorporated hydrogenated amorphous carbon (WO₃/a‐C:H) films have been fabricated on a single‐crystal silicon wafer by liquid phase electrodeposition using methanol as carbon source and tungsten carbonyl as incorporated reagent. The morphology, composition and structure of the films have been investigated by SEM, XPS, Raman scattering spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Transmission electron microscope (TEM), respectively. The effects of WO₃ incorporation on the electrical and wetting properties were studied in detail. The characterization results showed that tungsten trioxide nanocrystalline particles with diameters in the range of 10–20 nm were homogenously embedded in the amorphous carbon films. Also, the electrical conductivity and wetting ability of the films were strongly improved due to the contribution of the tungsten trioxide. Copyright © 2010 John Wiley & Sons, Ltd.