Surfactants are a type of chemical substance that can reduce surface or interfacial tension. They can gather on the interface in water or other solutions, change the characteristics of liquid-liquid or liquid-solid interface, and make it show good wetting, dispersion, emulsification, foam stability and other properties.
According to the dissociation properties of surfactants in water, they can be divided into the following categories:
Non ionic surfactants: do not produce ions in water. They are usually composed of organic compounds containing hydroxyl, ether, ester and other chemical structures, such as Fatty alcohol polyoxyethylene ether, fatty alkyd ester, etc. Non ionic surfactants have good adaptability to changes in hard water and acidity.
Anionic surfactant: Produces negatively charged ions in water. Anionic surfactants are usually formed by combining long-chain hydrocarbon groups with certain polar groups (such as Organosulfate group, sulfonic group, carboxylic acid group, etc.). Common examples include Sodium dodecyl sulfate (SDS), sodium sulfonated fatty acid, etc. Anionic surfactants have good cleaning and emulsifying properties, and are widely used in detergents, Dishwashing liquid and other products.
Cationic surfactant: Produces positively charged ions in water. Cationic surfactants are usually nitrogen containing compounds such as nitrogen and phosphorus combined with alkyl or aryl groups, such as hexadecyl trimethyl Ammonium bromide. Cationic surfactants have applications such as sterilization, ion exchange, and precipitation treatment.
Composite ionic surfactant: It is composed of non ionic surfactants and ionic surfactants combined in a certain proportion. Composite ion surfactants can combine the characteristics of both surfactants and improve certain properties, such as the solubility and emulsifying properties of cleaning agents.
It should be noted that there are various types of surfactants, each with its specific application and scope of application. In practical use, it is necessary to select suitable surfactants based on specific needs and follow relevant safety operating procedures.