Dispersing is the mixing of at least two substances that do not dissolve or hardly dissolve in each other and do not chemically react with one another. The goal while producing an industrial dispersion is to create a “”satisfactorily”” fine distribution in the continuous phase.
A suspension is created when solid particles are dispersed in a liquid. When dispersing a liquid in another liquid, an emulsion arises. At the boundary between two liquid phases of an emulsion, surface tension takes effect. The generation of new surfaces requires energy. Without external influence, each system aims for a state with preferably low energy. This way there will always be a tendency towards a preferably small boundary surface, which counteracts the creation of any emulsion.
In order to achieve the dispersal of non-mixable phases within one another, their particles must be crushed and mixed intensively. Crushing means that new surfaces must be created while getting over the resistance of the surface tension. The dispersing process delivers the required energy and ensures homogenous mixing of both phases. The long-time stability of the dispersion can be influenced by a definite particle size distribution as well as the use of emulsifiers and stabilizers.