Colloids

We observe various types of solutions in our everyday life. One of the types of solutions is a colloidal solution. A colloid is a heterogeneous system in which, one substance is dispersed as a very fine particle, in another substance. The particles of a colloid vary in size between 1 nm to 1000 nm and they are dispersed in a continuous medium. Colloid is an intermediate state between suspension and solution. Examples of colloids are milk, jelly etc. Dispersion system is a system in which a substance remains distributed as very small solid particles or liquid droplets or tiny gas bubbles in a suitable medium. Based on size of suspended particles, dispersion systems can be classified into true solutions, colloidal solutions and suspensions. A colloid has two components, dispersion medium and dispersed phase. The dissolved phase is called dispersed phase and the continuous phase is called dispersion medium. Based on the physical state of dispersed phase and dispersion medium, colloids may be of various types like solid sol, gel, foam etc. Colloids show specific properties like Brownian movement, Tyndall effect, electrophoresis etc. The continuous zig-zag movement of the colloidal particles in the dispersion medium in a colloidal solution is known as Brownian movement. The phenomenon of scattering of light by the colloidal particles is called the Tyndall effect. The movement of colloidal particles under the influence of an electric field towards an electrode is called electrophoresis. Various properties of true solution, colloidal solution and suspension can be compared. E.g., true solution is homogeneous while colloidal solution and suspension are heterogeneous in nature.

To Access the full content, Please Purchase