Surface Chemistry
9.0 Emulsions
9.0 Emulsions
Emulsions are those colloidal systems in which the dispersed as well as dispersion phase in normally liquid. In emulsions, the particles of dispersed phase are generally bigger than those in sols and are sometimes visible under the microscope. Emulsion particles carry a negative charge and are sensitive to the addition of electrolytes.
They show Tyndall effect and Brownian movement. In most of emulsions the two liquid phases are oil and water and thus emulsions may be of following two types:
1. Oil-in-water emulsions
In these emulsions, oil is dispersed phase and water is the dispersion medium. Milk and vanishing cream are the two important examples of this type of emulsion.
2. Water-in-oil emulsions
In these emulsions, water is the dispersed phase and oil is the dispersion medium. Butter and cold cream are the common examples.
