MoS2 PARTICLES MODIFIED WITH POLYSTYRENE FOR PRODUCING Ni–PS/MoS2 COATINGS

The MoS2 particles were coated with polystyrene and can be written as PS/MoS2 hereinafter. Ni–PS/MoS2 coatings and Ni–MoS2 coatings were produced by PC electrodeposition technique. The surface morphology of Ni–PS/MoS2 coating was examined and compared with those of Ni–MoS2 coating. The effect of particle concentrations on the volume percent of particles incorporated in the coatings was investigated. And the microhardness of coatings was also investigated. Results show that the surface morphology of Ni–PS/MoS2 coating is regular and the thickness of coating is uniform. The introduction of MoS2 to coatings caused dendritic growth. The surface morphology of Ni–MoS2 coating is irregular. With the same particles concentration in bath, the volume percent of PS/MoS2 particles incorporated in the composite coatings was higher than those of MoS2 particles; and the microhardness of Ni–PS/MoS2 coating was higher than those of Ni–MoS2 coating.MoS2 coated with polystyrene, composite coating, electrodeposition, 81.15.P

In Situ Reduction of Graphene Oxide Nanosheets in Poly(vinyl alcohol) Hydrogel by γ‑Ray Irradiation and Its Influence on Mechanical and Tribological Properties

Graphene-oxide-containing poly­(vinyl alcohol) (PVA/GO) composites prepared by the freeze–thaw method were irradiated by γ-rays at doses of 50, 100, 150, and 200 kGy to improve their strength and wear resistance. The effects of irradiation dose on the mechanical, thermal, and tribological properties were evaluated. The microstructure and composition of the PVA/GO hydrogels before and after irradiation were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results reveal that the irradiation can reduce the GO sheets dispersed in the PVA matrix in situ and that the reduced graphene oxide acts as the cross-linking point of the dangling bonds between molecular chains and forms covalent bonds after γ-ray irradiation, which endows the composites with high strength and improved thermal stability. Compared to the nonirradiated PVA/GO hydrogels, a 270% enhancement in compressive strength was obtained when the applied irradiation dose was 150 kGy. The friction coefficient of the PVA/GO hydrogels increased with increasing irradiation dose because of the loss of hydrophilicity. However, the wear resistance significantly improved upon irradiation treatment

Silver/Polypyrrole-Functionalized Polyurethane Foam Embedded Phase Change Materials for Thermal Energy Harvesting

Conversion of solar energy into thermal energy stored in phase change materials (PCMs) can effectively relieve the energy dilemma and improve energy utilization efficiency. However, facile fabrication of form-stable PCMs (FSPCMs) to achieve simultaneously energetic solar–thermal, conversion and storage remains a formidable challenge. Herein, we report a desirable solar–thermal energy conversion and storage system that utilizes paraffin (PW) as energy-storage units, the silver/polypyrrole-functionalized polyurethane (PU) foam as the cage and energy conversion platform to restrain the fluidity of the melting paraffin and achieve high solar–thermal energy conversion efficiency (93.7%) simultaneously. The obtained FSPCMs possess high thermal energy storage density (187.4 J/g) and an excellent leak-proof property. In addition, 200 accelerated solar–thermal energy conversion-cycling tests demonstrated that the resultant FSPCMs had excellent cycling durability and reversible solar–thermal energy conversion ability, which offered a potential possibility in the field of solar energy utilization technology

Mechanically Robust Superhydrophobic Steel Surface with Anti-Icing, UV-Durability, and Corrosion Resistance Properties

A superhydrophobic steel surface was prepared through a facile method: combining hydrogen peroxide and an acid (hydrochloric acid or nitric acid) to obtain hierarchical structures on steel, followed by a surface modification treatment. Empirical grid maps based on different volumes of H₂O₂/acid were presented, revealing a wettability gradient from “hydrophobic” to “rose effect” and finally to “lotus effect”. Surface grafting has been demonstrated to be realized only on the oxidized area. As-prepared superhydrophobic surfaces exhibited excellent anti-icing properties according to the water-dripping test under overcooled conditions and the artificial “steam-freezing” (from 50 °C with 90% humidity to the −20 °C condition) test. In addition, the surfaces could withstand peeling with 3M adhesive tape at least 70 times with an applied pressure of 31.2 kPa, abrasion by 400 grid SiC sandpaper for 110 cm under 16 kPa, or water impacting for 3 h without losing superhydrophobicity, suggesting superior mechanical durability. Moreover, outstanding corrosion resistance and UV-durability were obtained on the prepared surface. This successful fabrication of a robust, anti-icing, UV-durable, and anticorrosion superhydrophobic surface could yield a prospective candidate for various practical applications

Design and Fabrication of the Lyophobic Slippery Surface and Its Application in Anti-Icing

A suspension that can be sprayed onto substrates was developed to form a superhydrophobic/oleophilic surface. Lyophobic slippery surfaces were prepared by infusing perfluorinated lubricants into the superhydrophobic coating to repel almost all liquids with low surface tension values, including hexane, kerosene, and diesel oil, showing a transition between superoleophilicity and lyophobicity. In addition, the traveling speeds of liquids appeared to be negatively correlated with the kinematic viscosity. In the anti-icing tests, the droplet was pinned after contacting a 0 °C textured superhydrophobic surface for a few seconds because of the meniscus caused by the condensation of atmospheric humidity; by contrast, on the lyophobic slippery surface, a water droplet could easily slide even at −20 °C, demonstrating superior icing resistance