Dispersion (chemistry)
A dispersion is in chemistry, a heterogeneous mixture of at least two substances, which are not or hardly dissolve in each other or combine chemically. Here, a substance ( the dispersed phase ) is dispersed in another substance (dispersion medium). In general, there are colloids.
- Synonyms for disperse phase: dispersed phase, internal phase, secondary phase
- Synonyms for dispersion medium: dispersant, dispersant, continuous phase external phase, main phase
The individual phases can be clearly distinguished from each other and are usually separated again by physical methods (eg, filtration, centrifugation ), or they segregate by itself ( sedimentation ).
Classification according to particle size
After their particle size is dispersed phases can be divided as follows:
In a dispersion Are all particles of the same size, one speaks of a monodisperse system.
Classification according to physical states
Survey
In two-phase dispersions there is dependent on the aggregate states a total of eight types of dispersion:
A mixture of gases is more homogeneous and, therefore, no dispersion. Sets, for example, heavy carbon dioxide from an air mixture at the ground, although created an inhomogeneity, but no dispersion.