Colloid

A colloid, or colloidal dispersion, is a form of matter intermediate between a true solution and a mixture or suspension. Microscopic particles of one substance, said to be in the dispersed or solute phase, are distributed throughout another, said to be in the dispersing, continuous, or solvent phase.

Colloidal size - 0.001 micron to 1 micron in any dimension. Dispersions where the particle size is in this range are referred to as colloidal aerosols, colloidal emulsions, colloidal foams, or colloidal suspensions.

Colloids can be classified as follows:

Dispersed Phase

Gas Liquid Solid

Dispersing Phase Gas - Liquid aerosol,
e.g.: fog, mist Solid aerosol,
e.g.: smoke, dust

Liquid Foam,
e.g.: whipped cream Emulsion,
e.g.: milk, mayonnaise, hand cream Sol,
e.g.: paint, ink

Solid Solid foam,
e.g.: styrofoam Gel,
e.g.: gelatin, jelly, cheese Solid sol,
e.g.: ruby glass

		Dispersed Phase
		Gas	Liquid	Solid
Dispersing Phase	Gas	-	Liquid aerosol, e.g.: fog, mist	Solid aerosol, e.g.: smoke, dust
	Liquid	Foam, e.g.: whipped cream	Emulsion, e.g.: milk, mayonnaise, hand cream	Sol, e.g.: paint, ink
	Solid	Solid foam, e.g.: styrofoam	Gel, e.g.: gelatin, jelly, cheese	Solid sol, e.g.: ruby glass