The most typical emulsifier is soap, washing powder and other compounds, and its basic structure is an alkane chain with polar groups at the end. In human body, bile can emulsify fat and form smaller fat particles.
Emulsifier is a very important ingredient in skin care products. In each formula, the choice of emulsifier is always a key step, so the development of efficient, simple, safe and stable emulsifier is the key to produce cosmetics with excellent performance.
Emulsifiers are mainly used in creams, lotions and therapeutic cosmetics. Cream emulsion beauty and skin care products, such as vanishing cream, skin cream, spot removing cream, wrinkle removing cream, whitening cream, sunscreen milk, facial cleanser, etc. Emulsifier plays the role of emulsification, wetting and penetration.
Emulsifiers in water-based cosmetics can emulsify skin care raw materials and solubilize water-insoluble essence and essential oil. Therapeutic cosmetics are more and more popular with consumers. Emulsification technology can emulsify and solubilize active substances and drugs, which solves the problem of preparation technology of therapeutic cosmetics.
Extended data
The basic properties of emulsion are particle size, rheology and interfacial potential. The droplet size of emulsion can be expressed by the relative average droplet diameter, and the droplet size distribution corresponding to different droplet volume fractions can also be used to evaluate the droplet size distribution of emulsion.
At low concentration, the viscosity of emulsion is mainly determined by dispersion medium, which is related to the size and distribution of emulsion droplets, the fluidity of interfacial film formed by emulsifier and the charge it carries.
The viscosity of emulsion can be used as an evaluation index of its stability. The larger the droplet size and shear rate of emulsion dispersed phase, the smaller its viscosity and the worse its stability. When the emulsion droplets are charged due to ionization, adsorption and friction, they will move directionally in the electric field, and the charges on their surfaces will form an electric double layer structure.
References:
Baidu encyclopedia-emulsification