Chemistry

Color Property of Colloids The color of a lyophobic colloid depends not only on the color of the disperse phase but also considerably on the…

Optical Property of Colloids Colloids have some distinctive optical properties. The Tyndall phenomenon, named after Tyndall who extensively studied it, is attributed to scattering of…

Lyophilic colloids are liquid loving colloids (Lyo means solvent and philic means loving). Example: Sols of organic substances like gelatin, gum, starch, and proteins. Lyophobic…

Purification of Colloids: Dialysis and Electrodialysis After the preparation of the colloid, say, by a precipitation technique, it becomes necessary to remove the excess electrolyte…

Lyophobic and Lyophilic Sols A rough classification of sols, based on their methods of preparation, is sometimes made, e.g., association or condensation colloid, dispersion colloid…

Electrical disintegration: Bredig was the originator of disintegrating metals into sols by means of an electric arc. Two metallic electrodes dipped in water, as shown…

Disintegration or Dispersion method Whatever may be the technique the method consists in disintegrating or pulverizing a large form of the substance to colloidal dimension…

Sulphur Sol (oxidation): Preparation Sulfur sols are colloidal solutions of elemental sulfur or of sulfur-rich compounds. Sulphur sols can be prepared by the oxidation of H2S…

Ferric hydroxide sol (hydrolysis) THEORY: Ferric hydroxide forms a lyophobic sol with water which is the dispersion medium. It is prepared by the hydrolysis of…

Gold sol (reduction) This sol is of particular interest since it is the earliest sol prepared and studied. It was known well before Graham’s definition…