Preparation of Emulsion An emulsion is a dispersion of one liquid into another liquid in the form of small globules. Emulsions are generally prepared by dispersion methods. Most emulsions are prepared by mixing the two…

Importance of Colloids The study of colloids, lyophobic, lyophilic, molecular, or colloidal electrolytes is important not only for the satisfaction of an inquisitive mind but also from the practical point of view. There is hardly…

An emulsion is a dispersion of one liquid into another liquid in the form of small globules. Milk is a well-known emulsion. Many oils of animal or vegetable origin are used in medicine in the…

Imbibition and Swelling If some gelatin or agar is placed in water it first swells considerably and then either pass on to dispersion or remains as a gel, depending on the concentration of salt, pH…

Foam A dispersion of a gas in a liquid is called Foam. Ordinary soap solutions form lather which behaves like a foam if air-bubbles entrapped into it is reduced to colloidal dimension. Sol, gel, emulsion,…

All Gels are basically Sols but all Sols are not Gels If the sol is concentrated and the discrete particles are present in a state of bridged or cross-linked structure the system is called a…

Syneresis is the contraction of a gel accompanied by the separating out of the liquid. Many gels, if allowed to stand, are found to exude some water or the dispersion medium and the gel undergoes…

Peptization is the process by which a coagulum or a precipitate is dispersed to a colloidal state. It is the reverse process of coagulation. It is the process responsible for the formation of a stable…

The Electrical Double Layer The electrical properties of the colloidal state of matter and other associated phenomena may be explained in terms of the existence of an electrical double layer at the interface between two…

Electrophoresis is a chromatography technique by which a mixture of charged molecules is separated according to size when placed in an electric field. A simple experiment may be carried out in order to firmly establish…

Colligative Properties All molecular colloids in solution exhibit colligative properties. Since most of these colloids have high molecular masses the depression of freezing point, elevation of boiling point or lowering of vapor pressure is so…