Rigid, eco-friendly and superhydrophobic SiO2-Polyvinyl alcohol composite sponge for durable oil remediation

Scalable Fabrication of Superhydrophobic Coating with Rough Coral Reef-Like Structures for Efficient Self-Cleaning and Oil-Water Separation: An Experimental and Molecular Dynamics Simulation Study

Superhydrophobic coating has a great application prospect in self-cleaning and oil-water separation but remains challenging for large-scale preparation of robust and weather-resistant superhydrophobic coatings via facile approaches. Herein, this work reports a scalable fabrication of weather-resistant superhydrophobic coating with multiscale rough coral reef-like structures by spraying the suspension containing superhydrophobic silica nanoparticles and industrial coating varnish on various substrates. The coral reef-like structures effectively improves the surface roughness and abrasion resistance. Rapid aging experiments (3000 h) and the outdoor building project application (3000 m2 ) show that the sprayed superhydrophobic coating exhibits excellent self-cleaning properties, weather resistance, and environmental adaptability. Moreover, the combined silica-coating varnish-polyurethane (CSCP) superhydrophobic sponge exhibits exceptional oil-water separation capabilities, selectively absorbing the oils from water up to 39 times of its own weight. Furthermore, the molecular dynamics (MD) simulation reveals that the combined effect of higher surface roughness, smaller diffusion coefficient of water molecules, and weaker electrostatic interactions between water and the surface jointly determines the superhydrophobicity of the prepared coating. This work deepens the understanding of the anti-wetting mechanism of superhydrophobic surfaces from the perspective of energetic and kinetic properties, thereby paving the way for the rational design of superhydrophobic materials and their large-scale applications.

Design of an interface heating device based on polydivinylbenzene/SiO2/Bi2WO6 and its visible light response performance for water purification

Environmental pollution and the shortage of drinking water are the challenges that mankind is facing. Solar interface evaporation technology has been demonstrated as an important method for producing clean water, but its application to sewage still faces problems, mainly manifested in solubility and oily pollutants. Therefore, an evaporator device contains a superhydrophobic Bi₂WO₆ felt floating layer, a filter paper hydrophilic layer, and a copper foam/CuO photothermal layer, of which the water contact angle of the superhydrophobic felt can reach 159°. The floating layer not only has the ability to adsorb n-hexane but the Rh B degradation can also be realized under indoor/outdoor light conditions. The carrier life of Bi₂WO₆ is 28.8 ns. A copper foam/CuO photothermal layer prepared through a low-temperature treatment is combined with the floating and hydrophilic layer to obtain an evaporation rate of 1.53 kg m^-2 h^-1.