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In this paper, we present an improved lattice Boltzmann model for fluid–fluid–solid (FFS) flows with a high viscosity ratio. The bounce-back particle model is combined with the Shan–Chen (SC) multicomponent model. We extend the bounce-back scheme based on velocity interpolation and a fresh-node initialization approach with second-order accuracy to moving particles within the framework of the multicomponent model. An improved virtual solid density model for wetting boundary conditions is employed to implement contact angles on curved boundaries. We examine the factors that lead to the violation of mass conservation, and an easy redistributing method is developed to fix the mass leakage issue. The combined multiphase particle model is able to simulate FFS flows with a high viscosity ratio of up to 1000 while preserving the total mass of the two fluids. The performance of the approach is tested by a variety of numerical experiments. The dynamic behaviors of moving contact lines on the curved boundary are validated by a droplet wetting on a solid particle. The model is then applied to simulate dynamic FFS problems, such as particle wetting at the fluid interface and particle motion through a fluid–fluid interface. According to the simulation results, the present model is capable of capturing the total force exerted on a particle by the fluid and the interface. However, the SC-type fluid–solid interaction force does not equal the capillary force in the present model. Finally, the self-assembly process of two floating particles on a liquid–liquid interface is investigated. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials are promising next-generation waterproof materials due to their excellent self-cleaning, antifouling and additional capabilities. Herein, the superhydrophobic materials with excellent comprehensive performance were developed via a simple, low-cost, environmental, and scalable spray method with epoxy adhesive assistance. The epoxy adhesive enhanced the adhesion strength between spray coating and substrates significantly. Consequently, various properties of superhydrophobic coatings were improved greatly. The as-prepared superhydrophobic surfaces exhibited excellent mechanical durability. The water contact angle maintained unchanged basically and sliding angle only increased slightly even though sandpaper abrasion distance had extended to 2100 cm or tape-peeling test had reached 30 cycles. Moreover, the strong water repellence retained even after 72 h immersion in strong acid/alkali, 1 h treatment upon 280 °C, and 7 days exposure under 254 nm UV light. These indicated that the obtained superhydrophobic materials exhibited outstanding acid, alkali, high temperature, and UV light resistance and stability. Besides, the superhydrophobic materials demonstrated excellent self-cleaning and anti-icing performance. So the synthetic superhydrophobic materials were expected to have a wide range of applications in the industrial production and daily life. More importantly, they could be applied in a variety of harsh environments for long periods of time. [Display omitted] • Superhydrophobic surface with excellent comprehensive performance was fabricated by spray method. • The epoxy adhesive enhanced properties of superhydrophobic coatings significantly. • The superhydrophobicity maintained unchanged basically after 2100 cm sandpaper abrasion or 30 tape-peeling cycles. • The strong water repellence remained even after 72 h immersion in strong acid/alkali or 7 days exposure under UV light. • The superhydrophobic materials demonstrated excellent self-cleaning and anti-icing performance. [ABSTRACT FROM AUTHOR]

A superamphiphobic self-cleaning passive subambient daytime radiative cooling (SSC-PSDRC) coating was applied to distributed telecommunication base stations (d-TBSs) in different climatic regions and showed prominent subambient cooling effect under direct sunlight even after more than one year. Relative to the cool-white-coated counterparts, the SSC-PSDRC-coated d-TBSs significantly reduced the cooling energy consumption. Within experimental errors, the measured cooling energy savings agreed excellently with the theoretical values predicted using different methods. After five cycles of dirt- and 2200 h of artificial accelerated weathering-resistance tests, the solar reflectance of the superamphiphobic PSDRC coating decreased by 0.015 and 0.023, respectively. [Display omitted] • A passive subambient daytime radiative cooling (PSDRC) coating was fabricated. • The superamphiphobic topcoat had contact angles > 150° and sliding angles < 10°. • The coating was applied to distributed telecommunication base stations (d-TBSs) • The PSDRC-coated d-TBSs showed remarkable PSDRC effect even after one year. • PSDRC d-TBSs greatly save cooling energy use relative to cool white controls. A superamphiphobic self-cleaning passive subambient daytime radiative cooling (SSC-PSDRC) coating with ultrahigh solar reflectance and emissivity was applied to distributed telecommunication base stations (d-TBSs) in various climatic regions. The SSC-PSDRC surface showed remarkable PSDRC effect both in the absence and presence of heat-producing electronic equipment. After exposure to severe outdoor conditions for more than one year, the top surface of the spotless d-TBS still exhibited a strong subambient cooling effect under peak sunlight conditions, owing to the presence of the SSC topcoat. Regardless of the identical appearance, the top-surface temperature difference during the noon hours between the cool-white- and SSC-PSDRC-coated d-TBSs was as high as 24.2 °C, resulting in a chamber interior temperature decrease of the SSC-SDRC-coated d-TBSs. Consequently, the measured cooling energy consumptions of the SSC-PSDRC-coated d-TBS in Kashgar for one year and that in Panzhihua for 290 d were 1044.9 and 2083.3 kWh, respectively, both of which were underestimated. In the long term, the annual cooling energy conservations estimated using different methods correlated well with the measured value in Kashgar. After five cycles of dirt- and 2200 h of artificial accelerated weathering-resistance tests, the solar reflectance of the SSC-PSDRC coating decreased by only 0.015 and 0.023, respectively. These excellent performances were attributed to the unique molecular structure of the superamphiphobic topcoat which contained networks of –Si–O–. [ABSTRACT FROM AUTHOR]

The precise waterproofing mechanism for sodium silicate-based concrete sealers was experimentally explored using a Leeb hardness tester, a Fourier transform infrared spectroscopy, an X-ray diffraction microscopy, a thermal-gravimetric analysis, a surface area and porosity analyzer, a scanning electron microscope and an optical contact-measuring device. After treating the concrete surface with a sodium silicate-based concrete sealer, the new substance-sodium hydroxide-introduced into the concrete structure is undetectable most likely because of the quite low concentration and its migration to the concrete surface. The surface hardness of the concrete specimens impregnated with the sodium silicate-based concrete sealer is found to be increased by approximately 11.9% relative to the untreated concrete specimens. The content of the calcium hydroxide in the concrete structures decreases whereas the content of the calcium silicate hydrate (C–S–H gel) in the concrete structures increases compared with the untreated concrete structures. Sodium silicate-based concrete sealers are essentially surface hydrophilic agents, yet they do reduce the velocity of water ingress into the concrete structures, because the expansive and insoluble C–S–H gels partially fill the micro-pores, micro-voids and micro-cracks in the concrete structure to form smaller micro-pores, micro-voids and micro-cracks and improve the compactness and water impermeability of the concrete. [ABSTRACT FROM AUTHOR]

Waterborne and solvent-based coatings with prominent passive subambient daytime radiative cooling (RC) coatings were fabricated to conserve cooling energy in the summer. Concurrently, water- and alcohol-based superamphiphobic self-cleaning coatings were manufactured and introduced into the RC coatings as topcoats. The contact angles of water and n -hexadecane of the superamphiphobic topcoat containing coating systems were 163.4° and 151.4°, respectively; additionally, the sliding angles of water and n -hexadecane of these systems were 2° and 9°, respectively. Moreover, the introduction of a transparent superamphiphobic topcoat to the RC coatings did not affect their originally high solar reflectance but improved their emissivity values in the atmospheric transparency window, wavelengths between 2.5 and 24 μm, and the entire infrared spectrum due to the presence of plenty of silicon-oxygen bonds formed via hydrolysis and/or alcoholysis reactions and the subsequent co-polycondensation of tetraethoxysilane and 1H,1H,2H,2H-perfluorodecyltriethoxysilane. The solar reflectance of the coating system was 0.986, which is the highest recorded worldwide. The emissivity of the superamphiphobic RC coatings in the atmospheric transparency window was 0.954. The superamphiphobic RC coatings possessed excellent static and dynamic non-wetting capabilities, significantly improving their water resistance, waterproofing properties, and anti-graffiti performance. Additionally, the superamphiphobic RC coatings exhibited outstanding self-cleaning properties, preventing the coating surfaces from being contaminated by dust, soiling, grime, and water/oil-soluble pollutants, thereby enabling them to maintain an extremely high solar reflectance. Water- and alcohol-based superamphiphobic radiative cooling coatings with solar reflectance up to 0.986 were fabricated. The emissivity in the atmospheric transparency window and thereby the overall emissivity were increased to 0.954 and 0.96, respectively, due to the introduction of transparent superamphiphobic topcoats. The contact angles of water and n -hexadecane were 163.4°and 151.4°, respectively, while the sliding angles of water and n -hexadecane were 2°and 9°, respectively. [Display omitted] •The superamphiphobic coating with subambient daytime radiative cooling was produced. •The solar reflectance of the coating was up to 0.986 •The coating's emissivity in the atmospheric transparency window was 0.954 •The coating's contact angles of water and n-hexadecane were higher than 150°. •The coating's sliding angles of water and n-hexadecane were lower than 10°. [ABSTRACT FROM AUTHOR]