Emulsions - Types and its Uses

What is emulsion?

An emulsion is generally defined as a mixture of 2 or more immiscible liquids. Emulsions are a member of 2 phase systems known as colloids. In an emulsion, one liquid is dispersed in the other. Although the terms emulsion and colloid are used interchangeably, the emulsion must be used when both the phases i.e. dispersed and continuous are liquids. Some common examples of emulsions are homogenized milk, vinaigrettes, mayonnaise, and cutting fluids for metal forming.

The emulsion is a dispersion of one form of liquid into another form of liquid. Have you ever wondered about the cosmetics you use, what does it consist of? Most of the cosmetic products are based on the term known as an emulsion. The cream and lotions that you use are cosmetic products based on the emulsion.

Types of emulsions

Depending on the nature of the dispersed phase, the emulsions are classified as:

  • Oil in water

Let’s start with the discussion of oil dispersed in water. Here, the dispersion medium is water and this kind of emulsion can be found in applications which have a small quantity of fatty material like moisturizing creams. Now, let’s discuss the case of milk which also lies in this type of emulsion. Milk consists of liquid fat which gets dispersed in water. These types of emulsions are unstable and hence can be separated into two different layers when at rest. Therefore, to balance the emulsion, another component called emulsifying agent is added. This emulsifying agent enables the medium and the suspended particles to mingle. These emulsifying agents can be gum, proteins, synthetic soaps, etc.

  • Water in oil

Now, let’s discuss with water dispersed in oil. Here, the dispersion medium is oil and its application can be found in butter and cream. Where do you find water in oil dispersion? We can find this in sunscreens as this type of emulsion has a higher sun protection factor and they are also better water-resistant than oil in water emulsion.

Uses of emulsions

Let’s differentiate between the two items to give a clear view of the two types of emulsions. Consider butter and cream, where the cream is oil in water emulsion and butter is water in oil emulsion. Literally, they are the same thing but butter is an emulsion resulting from the inversion of the cream which is an oil in water emulsion.

  • Cleansing action of soaps
  • The process of emulsification is utilized to make medicines.
  • Digestion of fats in intestines
  • Disinfectants and antiseptics when mixed with water forms emulsions.