Wetting agents, as an important type of surfactant, play an indispensable role in daily life and industrial production. They can significantly alter the wetting properties of liquids on solid surfaces, making many previously difficult to implement processes possible. The following is a deep analysis of the magical mechanism and principle of wetting agents.

Wetting agents refer to a type of chemical substance that can reduce the surface tension of liquids, making them easier to spread or penetrate on solid surfaces. They form a thin film by adsorbing on the surface of solids, thereby reducing the interfacial tension between solids and liquids and promoting the wetting effect of liquids.

Wetting is a process in which a fluid replaces another fluid from a solid surface, and can be divided into three types: wetting, soaking, and spreading. In this process, wetting agents work through the following mechanism: wetting agent molecules have amphiphilicity, with one end hydrophilic (polar group) and the other end lipophilic (non-polar group). When wetting agent molecules adsorb on the surface of a liquid, their hydrophilic groups face towards the interior of the liquid, and their lipophilic groups face towards the air, thereby reducing the surface tension of the liquid. This makes it easier for liquids to spread and permeate on solid surfaces. When the wetting agent comes into contact with a solid surface, its lipophilic groups will adhere to the solid surface, while the hydrophilic groups will extend outward into the liquid. In this way, a continuous phase composed of wetting agent molecules is formed on the solid surface. This continuous phase not only reduces the interfacial tension between solid and liquid, but also enables the liquid to form a stable thin film on the surface of the solid. Contact angle is an important parameter for measuring the wetting performance of solid surfaces. The angle formed at the junction of solid, liquid, and gas phases when a liquid comes into contact with a solid surface is called the contact angle. The function of wetting agents is to reduce the contact angle, making it easier for liquids to spread on solid surfaces. When the contact angle is 0 °, it is called complete wetting; When the contact angle is between 0 ° and 90 °, it is called wetting; When the contact angle is greater than 90 °, it is called non wetting.

The mechanism of action of wetting agents can be summarized as follows: wetting agent molecules adsorb onto solid surfaces through physical or chemical adsorption, forming a continuous thin film. This thin film reduces the interfacial tension between solids and liquids, making it easier for liquids to spread on the surface of solids. Wetting agent molecules can penetrate into the tiny pores on the surface of solids, displacing gases or liquids that originally existed. This permeation effect not only improves the wetting performance of the solid, but also helps to improve the surface quality of the solid. In industries such as coatings and inks, wetting agents can also disperse solid particles such as pigments and fillers in liquids, forming stable suspensions. This helps to improve the fluidity of the coating and the smoothness of the coating. In some cases, wetting agents can also act as lubricants, reducing friction and wear between solid surfaces. This lubrication effect is particularly important in industries such as metal processing and textiles.

Wetting agents play an important role in daily life and industrial production due to their unique amphiphilic structure and excellent performance. They promote the wetting effect of liquids by reducing surface tension, forming continuous phases, and changing contact angles. At the same time, wetting agents also have multiple mechanisms of action such as adsorption, permeation, dispersion, and lubrication, providing strong support for the development of various industries.