Classification of colloids |
Types of colloidal systems- examples, lyophilic and lyophobic— differences and examples, macromolecular, multimolecular and associated colloids, examples, formation of micelle, cleansing action of soaps. Preparation of colloids-chemical methods sulphur and ferric hydroxide sols, Bredig’s arc method for metal sols, peptization. Purification– dialysis, electro-dialysis, ultrafiltration Properties of colloids: Tyndall effect, Brownian movement, charge on colloidal particles, examples, electrophoresis, coagulation – methods of coagulation of lyophobic sols, HardySchulze rule-examples, coagulating value. Protective colloid – example. Applications: In industries, medicines, purification of drinking water. |