“Emulsions are the colloidal solutions in which both the dispersed phase and the dispersion medium are liquids.”
A good example of an emulsion is milk in which fat globules are dispersed in water. The size of the emulsified globules is generally of the order of 10–6m. Emulsion resembles lyophobic sols in some properties.
Types of Emulsions
Depending upon the nature of the dispersed phase, the emulsions are classified as; phase, the emulsions are classified as;
Oil-in-water emulsions (O/W):
The emulsion in which oil is present as the dispersed phase and water as the dispersion medium (continuous phase) is called an oil-in-water emulsion. Milk is an example of the oil-in-water type of emulsion. In milk liquid fat globules are dispersed in water. Other examples are vanishing cream etc.
Water-in-oil emulsion (W/O):
The emulsion in which water forms the dispersed phase, and the oil acts as the dispersion medium is called a water-in-oil emulsion. These emulsions are also termed oil emulsions. Butter and cold cream are typical examples of this types of emulsions. Other examples are cod liver oil etc.