Wetting agents, as a type of surface active substance, have the core function of reducing the interfacial tension between liquid and solid surfaces, making it easier for liquids to spread or penetrate into solid surfaces. In the fields of chemistry, physics, and engineering, wetting agents are widely used. They promote the uniform distribution of liquids on solid surfaces by changing the physical and chemical properties of interfaces, thereby enhancing wetting effects, improving processing performance, or enhancing product performance.

Wetting agents are usually divided into four categories: anionic, cationic, nonionic, and zwitterionic. Each type is suitable for different application scenarios based on its specific chemical structure and charge properties. Its working principle is that the hydrophilic groups in the wetting agent molecules are oriented towards the aqueous phase, while the hydrophobic groups are adsorbed on the solid surface. This molecular arrangement effectively reduces the contact angle between water and the solid, allowing water to cover the solid surface more smoothly.