what is the emulsifier ?

Lotion type

Emulsions can be classified based on the properties of the dispersed phase and the dispersion medium.

1) Oil-in-water (O/W):

In this type of emulsion, oil will become the dispersed phase and water will become the dispersion medium. The best example of O/W emulsion is milk. In milk, fat globules (acting as a dispersed phase) are suspended in water (acting as a dispersion medium).

2) Water in oil (none):

In this type, water will become the dispersed phase and oil will become the dispersion medium. Margarine (a spread used for flavoring, baking and processing) is an example of a water-in-oil emulsion.

Emulsifier

These are substances added to the emulsion for stability. The various characteristics of emulsifiers are as follows:

They are substances with a hydrophilic end (polar) and a hydrophobic end (non-polar).

They are soluble in water and oil.

The emulsifier forms a layer between the dispersed phase and the dispersion medium, thereby preventing the dispersed phase particles from gathering together to form larger particles and separating out.

Emulsifiers can be cationic, anionic or even non-polar.

It is not only the percentage of water and oil that determines whether water is a water-in-oil or a water-in-oil emulsion. On the other hand, it depends on which of water and oil can dissolve the emulsifier to a greater extent.

If the emulsifier is more soluble in water than water, the water becomes the dispersion medium and the oil becomes the dispersed phase, so we get an oil-in-water emulsion.

On the other hand, if the emulsifier is more soluble in oil, the oil becomes the dispersion medium and the water becomes the dispersed phase.

Commonly used emulsifiers for O/W emulsions are protein, gum, soap, etc.

The commonly used emulsifiers for anhydrous emulsions are heavy metal salts of fatty acids, long-chain alcohols, etc.

Some common examples of emulsifiers are egg yolk, mustard, sodium phosphate, DATEM, mono and diglycerides, cellulose, soy lecithin, etc.