Narrow Results

In this study, the apparent contact angles of oil droplets on the rough surfaces in water were numerically studied using the Volume of Fluid (VOF) model. The results showed that the roughness of the surface affected the wettability. By increasing the roughness of the surface, the oleophilicity of the oleophilic surface and the oleophobicity of the oleophobic surface could be increased. Furthermore, the applicability and limitations of the prediction of the underwater apparent contact angle of the oil droplet by the contact angle model were investigated by 3D numerical simulations. It suggests that Wenzel model can accurately predict the underwater apparent contact angle of oil droplets on all the oleophilic, neutral and oleophobic surfaces, and Cassie model can only be applied to the oleophobic surface and Cassie–Baxter model can only be applied to the oleophilic surface.

In this study, CuS/SiO₂ composite modified aerogel was prepared by the incorporation of hollow spherical CuS into methyltrimethoxysilane-based SiO₂ sol and modification with hexadecafluorodecyltriethoxysilane via acid-base catalyzed sol–gel reaction and drying under ambient pressure. The CuS/SiO₂ composite modified aerogel was characterized by Fourier-transform infrared (FT-IR) spectrometry, scanning electron microscope (SEM), nitrogen gas adsorption and desorption and X-ray diffraction (XRD), respectively. The effects of CuS and fluorosilane concentration on density and porosity of aerogel, oleophobic and photocatalytic properties were evaluated. The results showed that structure and physical properties of aerogel had some effect by introducing CuS and fluorosilane, and the CuS/SiO₂ composite modified aerogel with density of 0.146g/cm³ and specific surface area of 241m²/g achieved super-oleophobicity with oil contact angle of 152.8^∘ and sliding angle of 10^∘, and good photocatalytic properties for methylene blue.