Sol
A colloidal system consisting of solid particles dispersed throughout a liquid medium.
Unit
nm
In depth
Sols are stabilised by the mutual repulsion of like charges adsorbed on the particle surfaces, which prevents them from clustering. Adding electrolyte neutralises those charges and causes coagulation, a principle used in water treatment and in the destabilisation of river-borne silt at estuaries.
Examples in the real world
Gold sol, Indian ink, muddy water, and starch dispersed in water.