3. Preparing emulsions

Emulsions are dispersions of a liquid, such as oil, in another immiscible liquid, such as an aqueous phase. As these systems are not at thermodynamic equilibrium, they are bound to evolve towards macroscopic separation of the two fluids. Emulsions can nevertheless be kinetically stabilized by adsorption of species at the interface: surfactants, polymers, proteins or particles. Commonly used stabilizers are surface-active molecules comprising a hydrophilic polar head and a lipophilic aliphatic chain, with a low molar mass and an adsorption...