Colloidal dispersions are thermodynamically unstable owing to their high surface free energy and are irreversible systems in the sense that they are not easily reconstituted after phase separation.

What makes a colloid unstable?

A colloidal dispersion is composed of solid, liquid or gas particles dispersed in a continuous phase (solid, liquid or gas). ... Colloidal dispersion is an inherently thermodynamically unstable system because it tends to minimize surface energy.

Is colloid stable or unstable?

A colloid is stable if it does not get coagulated easily. - The dispersed phase and dispersion medium have charges present on them. Colloidal particles form a sheath of charge on themselves thereby preventing any attraction between opposite charges.