Chemistry · Ch 12 — Surface Chemistry
Classification Based on Nature of Interaction between Dispersed Phase and Dispersion Medium
12.4.2
Classification Based on Nature of Interaction between Dispersed Phase and Dispersion Medium
Depending on how strongly the dispersed phase interacts with the dispersion medium, sols are split into two categories. When water is the medium, the terms become hydrophilic and hydrophobic.
(i) Lyophilic colloids ("liquid-loving")
Formed simply by mixing substances such as gum, gelatine, starch or rubber with a suitable liquid. Their key trait is reversibility: if the medium is removed (say by evaporation), the sol can be reconstituted just by remixing — hence they are called reversible sols. They are quite stable and not easily coagulated.