THREE ROLES OF SURFACTANTS.

Surfactant refers to a substance that can significantly change the interface state of a solution system by adding a small amount of it. It has fixed hydrophilic and lipophilic groups and can be oriented on the surface of the solution. The molecular structure of the surfactant is amphiphilic: one end is a hydrophilic group and the other end is a hydrophobic group; the hydrophilic group is often a polar group, such as a Calcium Salt, a sulfonic acid, a sulfuric acid, an amino group or an amine group and Its salts, hydroxyl groups, amide groups, ether bonds, etc. can also be used as polar hydrophilic groups; while hydrophobic groups are often non-polar hydrocarbon chains, such as hydrocarbon chains with more than 8 carbon atoms. Surfactants are divided into ionic surfactants (including cationic surfactants and Anionic Surfactants), Non-Ionic Surface-Active Agents, amphoteric surfactants, compound surfactants, and other surfactants.

Its basic definition is that any substance dissolved in water that can significantly reduce the surface energy of water is called a surface active agent (SAA) or a surface active substance. However, the traditional concept is that surfactants are a class of substances that can significantly reduce surface (boundary) surface tension even at very low concentrations. With the deepening of the research on surfactants, it is generally believed that as long as substances that can significantly change surface (boundary) surface properties or related properties at lower concentrations can be classified as surfactants.

Surfactants have a series of physical and chemical effects such as wetting or anti-sticking, emulsification or demulsification, foaming or defoaming, solubilization, dispersion, washing, anti-corrosion, anti-static, and corresponding practical applications, and have become a class of flexible and diverse. Widely used fine chemical products. Surfactants can be used in almost every field of fine chemicals except for their use as detergents in daily life.

Wetting effect, HLB: 7-9. The use of surfactants can control the degree of wetting between liquid and solid. In the pesticide industry, some of the granules and powders for dusting also contain a certain amount of surfactant. The purpose is to improve the adhesion and deposition of the agent on the surface of the drug, and improve the effective ingredients in the presence of moisture. Lower release speed and expanded area to improve the effect of disease prevention and treatment. In the cosmetics industry, as an emulsifier, it is an indispensable ingredient in skin care products such as creams, lotions, cleansing and makeup removers.

Suspending effect In the pesticide industry, wettable powders, emulsifiable concentrates, and concentrated emulsions all require a certain amount of surfactants. For example, the original drugs in wettable powders are mostly organic compounds and have hydrophobic properties, which can be reduced only in the presence of surfactants. The surface tension of the water makes it possible for the granules to be wetted with water and form an aqueous suspension.

Disinfection and sterilization can be used as bactericides and disinfectants in the pharmaceutical industry. Their sterilization and disinfection effects are attributed to their strong interaction with bacterial biofilm proteins that denature or lose their functions. These disinfectants are compared in water. Large solubility, depending on the concentration used, can be used for skin disinfection before surgery, wound or mucous membrane disinfection, instrument disinfection and environmental disinfection.