Super-hydrophobic coating technology is a broad-based and highly practical basic technology that has a wide range of applications in people's daily lives. By designing coatings of different structural, chemical and physical characteristics, it is possible to provide new additional functions of solid materials, especially the rapidly growing demand for superhydrophobic coatings in modern industry, to give functionalized hydrophobic coatings a vitality. Superhydrophobic coatings are the new surface technology developed on this basis.

Hydrophobic coatings often refer to a class of low surface energy coatings with a static water contact angle θ of greater than 90° on a smooth surface, while superhydrophobic coatings are a new type of coating with special surface properties, which refers to the water contact of solid coatings. Angle is greater than 150 ° and often refers to water contact angle hysteresis less than 5 °, with waterproof, anti-fog, anti-snow, anti-pollution, anti-blocking, anti-oxidation, anti-corrosion and self-cleaning and prevent current conduction, etc., in scientific research and production There are extremely wide application prospects in many fields such as life.

Theoretical model

The wetting characteristics of liquids on solid surfaces are often described by the Young's equation. The contact angle between the droplet and the solid surface is large, the wettability is poor, and the liquid repellency is strong; otherwise, the liquid repellency is strong. The hydrophobicity of the solid surface is closely related to the surface energy of the solid surface. The solid surface energy is low, the static water contact angle is large, and the water contact angle is greater than 90°, which is obviously hydrophobic. Currently known hydrophobic materials, silicone, organic fluorine materials have low surface energy, and the surface energy of the fluorine-containing groups decreases in the order of -CH2->-CH3>-CF2->CF2H>-CF3. The surface energy of the -CF3 group is as small as 6.7 m J/m2, and the water contact angle on the smooth plane is large. The Dupre formula can be calculated as 115.2°, self-assembled ordered monolayer of long-chain hydrocarbon groups. The water contact angle can reach 112°. The water contact angles of the silicone and organic fluoropolymers, which are usually arranged with a low surface energy, are 101° and 110°, respectively.