emulsion

https://doi.org/10.1351/goldbook.E02065
A fluid @C01172@ system in which liquid droplets and/or liquid crystals are dispersed in a liquid. The droplets often exceed the usual limits for @C01171@ in size. An emulsion is denoted by the symbol O/W if the continuous phase is an aqueous solution and by W/O if the continuous phase is an organic liquid (an 'oil'). More complicated emulsions such as O/W/O (i.e. oil droplets contained within aqueous droplets dispersed in a continuous oil phase) are also possible. Photographic emulsions, although @C01172@ systems, are not emulsions in the sense of this nomenclature.
Source:
PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 606 [Terms] [Paper]