An emulsifier is a substance that assists in the formation and promotes the stability of an emulsion. This substance can come in a number of different forms and from various sources, though it will typically consist of a molecule with two different ends. One end bonds with water, which is called the hydrophilic end, and the other bonds with an oil or similar substance, which is called the hydrophobic end. An emulsifier that is added to a chemical combination of an oily substance and water will work to create a protective barrier around the oily molecules that promotes and stabilizes the formation of an emulsion.
Though an emulsifier can be used for medical purposes, it is also quite commonly found in beauty products and foods. This type of substance is used in the formation of an emulsion, especially in helping that emulsion remain stable for a longer period of time. An emulsion is a mixture of two substances, often liquids, which are not naturally able to successfully combine. An example is when water and oil are combined, which results in the oil forming globs separate from the water itself.
The addition of an emulsifier to this type of compound helps stabilize an emulsion. Many emulsions can be made through the application of kinetic energy, such as the shaking of a vinaigrette dressing, but in a fairly short period the emulsion can break down and return to separate chemicals. When an emulsifier is added to an emulsion, it helps increase the stability of the emulsion and encourage the chemicals to remain together. This is often done by the emulsifier coating the molecules of the chemical that has been added to the mixture, such as the oil added to water, which prevents that chemical from grouping together and separating from the mixture.
An emulsifier is often used in the production of medical treatments, such as creams, balms, and ointments. These medicines usually consist of a carrier, such as water, to which a chemical with medicinal properties is added. This emulsion is stabilized by the addition of an emulsifier to prevent separation and allow the cream or ointment to remain usable for months or years after creation. Emulsions are also commonly made in food preparation, such as vinaigrette dressings and mayonnaise, as well as in beauty supplies like facial creams. Common emulsifiers include soy and egg lecithin as well as honey, mustard, and various proteins.