Is emulsification a chemical or physical change

Emulsification is a physical change.

I. Analysis

Emulsification is a physical change, the essence of the emulsifier hydrophilic and water fusion, hydrophobic and oil fusion to make the system homogeneous and stable, of course, does not exclude some emulsifiers and substances to produce chemical reactions.

Two, emulsion

Emulsion preparation in determining its reasonable formula, its emulsification technology is also extremely important. The preparation of cosmetics is mainly mixing technology. Although the mixing technology is relatively simple, but as a cosmetic product, requires a variety of functions and properties, to prepare a cosmetic product such as emulsion with excellent and stable properties, is not a simple matter.

Three, emulsification theory

Emulsions are the most widely used dosage forms in cosmetics, ranging from watery fluids to viscous creams. Therefore, the discussion of emulsion is extremely important to the research and production of cosmetics, as well as preservation and use.

Emulsification technology:

1, aqueous phase preparation

According to the formula, water-soluble substances, such as glycerol, colloidal raw materials, etc., as much as possible dissolved in water. Preparation of the temperature of the aqueous phase, depends largely on the physical properties of the components in the oil phase, the temperature of the aqueous phase should be close to the temperature of the oil phase, such as lower than the temperature of the oil phase.

It should not exceed 10 ℃. In the preparation of emulsion, the emulsifier is added by a variety of ways, the emulsifier is added to the water to form the water phase, and then added to the oil phase under intense stirring, the formation of emulsion method, often called the agent in the water method of emulsification method.

2, oil phase preparation

According to the formula, all the components of the oil phase will be dissolved together in a container, such as high melting point of wax, fatty acids, alcohols and other components of the oil phase, then this time you need to heat up, melt the oily components, so as to keep them in a liquid state.

Also if the oil-phase solution tends to solidify or freeze when cooled, then the temperature of the oil phase should be kept at least 10℃ above the solidification temperature to keep the oil phase in a liquid state and to facilitate emulsification with the water phase. When a nonionic surfactant is used as the emulsifier, the hydrophilic or lipophilic emulsifier is often dissolved in the oil phase.

This method of preparing emulsions is often called the agent in oil method. If the emulsion formula has the use of fatty acids, the fatty acids dissolved in the oil phase, while the alkali dissolved in water, the two phases are mixed, that is, the formation of soap at the interface. And get a stable emulsion. This method of preparing emulsion is called primary soap method, is a more traditional method of preparing emulsion.