Surfactants are compounds that lower the surface tension between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants can be used as detergents, wetting agents, emulsifiers, foaming agents and dispersants. Surfactants are usually amphiphilic organic compounds, which means that they contain both hydrophobic groups and hydrophilic groups. Thus, surfactants contain both water-insoluble and water-soluble components. In the case where water is mixed with oil, the surfactant will diffuse into the water and adsorb at the interface between air and water or at the interface between oil and water. Water-insoluble hydrophobic groups can stick out of the bulk aqueous phase into the air-oil phase, while the water-soluble groups remain in the aqueous phase. Surfactants have a class of flexible applications due to a series of physicochemical effects, and are used in wide range of fine chemical products. In addition to being detergents in daily life, other applications of surfactants can cover almost all fine chemical fields.
Applications
Solubilization: Solubilization can greatly increase the solubility of water-insoluble organics. The solubilizing capacity is related to the structural characteristics of the surfactant, temperature, organic and inorganic additives, and so on.
Wetting agents: The surfactants can be used wetting agents between liquids and solids. In the pesticide industry, granules and powders for dusting also contain a certain amount of surfactants. The purpose of adding surfactants is to increase the adhesion and deposition of the drug, and to increase the activity of active ingredient in the presence of moisture.
Foaming and defoaming: Surfactants are also widely used in the pharmaceutical industry. In pharmaceuticals, some volatile oil-soluble celluloses, steroid hormones and many other insoluble drugs make use of surfactants to form transparent solutions and increase the concentration. During the preparation of pharmaceuticals, surfactant is an indispensable emulsifier and moisturizing agent, suspending agents, foaming agents and so on.
Sterilization: In the pharmaceutical industry, surfactants can be used as fungicides and disinfectants. Their bactericidal and disinfecting effects can be attributed to their strong interaction with bacterial biofilm proteins that cause bacteria lose their function. These surfactants have relatively large solubility in water. The surfactants can be used for preoperative skin disinfection, mucosal disinfection, device disinfection and environmental disinfection depending on different concentrations.
