Lyophilic sols: Lyophilic sols are those sols in which the particles of dispersed phase have great affinity for the dispersion medium, e.g., sols of gum, gelatine, starch, etc.
Lyophobic sols: In this type of sols the particles of dispersed phase have little or no affinity for the dispersion medium, e.g., gold sol, Fe (OH)3 sol, As2O3 sol., etc. Lyophobic sols easily coagulate on the addition of small amount of electrolyte because these are not stable. The stability of Lyophobic sols is only due to the presence of charge on the colloidal particles, on the other hand stability of lyophilic sol. is due to charge as well as solvation of colloidal particles.