(i) Lyophilic colloids : They are prepared easily by directly mixing with liquid dispersion medium. Ex-Gelation, starch etc. They are reversible in nature and are quite stable and are not easily precipitated or coagulated.
(ii) Zeta potential : When one type of ions of electrolyte are adsorbed on the surface of colloidal perticles it forms a fixed layer. It attracts the counter ions to form secound layer which is mobile is called diffused layer. The potential difference between fixed layer and diffused layer is known as Zeta potential.
(iii) Associated colloids : They are formed by the aggregation of large no. of ions concentrated solution. Their molecular masses are high. The aggregate parties the formed are called micelles.