The Four Major Functions of Surfactants

Surfactants have the following four main functions:

Reducing surface tension: Surfactants can reduce the surface tension of liquids, making them easier to unfold on the surface. Surface tension is the force generated by the mutual attraction between liquid molecules, which causes the liquid to contract into a spherical shape. Surfactant molecules contain both hydrophilic and hydrophobic groups, which can form an adsorption layer on the surface of the liquid, reducing its surface tension and making it easier for the liquid to wet and flow.

Dispersion and emulsification: surfactants can disperse water insoluble substances into water or water insoluble substances to form a stable dispersion system or lotion. The molecular structure of surfactants has both hydrophilic and hydrophobic groups, which can interact with both water and non-polar substances, thereby altering their interfacial properties, enabling them to disperse and maintain stability.

Wetting effect: Surfactants can improve the contact between liquids and solids, enhancing the unfolding ability of liquids on solid surfaces. Wetting refers to the reduction of the contact angle between a liquid and a solid, making it easier for the liquid to expand and cover the solid surface. Surfactants reduce the mutual attraction between liquids and solids, alter their interfacial properties, and thus improve their wetting effect.

Penetration and cleaning effects: Surfactants can penetrate into surfaces such as dirt, grease, and reduce their interaction with the substrate, making it easier to clean. Surfactants have good oil-water compatibility and can effectively dissolve and disperse organic substances such as oil and dirt. By penetrating the surface of dirt and changing its interfacial properties, surfactants can separate dirt from the substrate and make it easy to clean.

These four major functions make surfactants widely used in various fields, including detergents, emulsifiers, coatings, pharmaceuticals, pesticides, etc. They play an important role in industrial production, daily life, and scientific research.