Man's physical universe



3. Colloidal Dispersions. Colloidal dispersions (colloids, or colloidal

solutions) are mixtures whose dispersed ingredients range in size from

about 1 to 100 millimicrons in diameter. The ingredients in a colloidal

dispersion cannot be seen except with the aid of an ultramicroscope,

and not always then.

The physical properties of colloids differ considerably from the

properties of solids, liquids, and gases because the particles are much

larger than molecules.

For that reason, many people consider colloidal

dispersions to represent a special state of matter.

Inasmuch as the dispersed and dispersion phases may exist in the

solid, liquid, or gaseous states, nine types of colloidal dispersions would

seem to be possible. These nine types are listed as follows with examples

illustrating the type in each case, although the dispersed phase in

some of the mixtures mentioned is usually larger than colloidal in size.

State of Dispersion


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