Lyophilic sols – Lyophilic sols are colloidal sols made by combining ingredients like gum, gelatin, starch, and others in a liquid called the dispersion medium. These sols are reversible in nature. This implies that if two parts of sol are separated by any process, such as evaporation, the sol can be reconstituted by shaking.

Lyophobic sols – When components such as metals and their sulfides are combined with the dispersion medium, lyophobic sols are formede. Their colloidal sols are made using only specialized procedures. Lyophobic sols are those that are lyophobic in nature. These sols are irreversible. For instance, sols of metals.

Two things determine the stability of hydrophilic sols – the salvation of a colloidal particle and the presence of a gas.

At the same time, the presence of a charge too determines the stability of a hydrophobic sol. As a result, the former is significantly more stable than the latter. When the charge on hydrophobic sols is eliminated (by adding electrolytes), the particles in the sols move closer together and form aggregates, resulting in precipitation.