Colloidal suspension

Colloidal Suspension

A colloidal suspension is a type of heterogeneous mixture where tiny particles of one substance are dispersed, but not dissolved, in another substance. The particles in a colloidal suspension are larger than those in a solution, but smaller than those in a suspension. The substance being dispersed is referred to as the dispersed phase, while the substance in which it is dispersed is called the dispersion medium.

Characteristics

Colloidal suspensions exhibit several unique characteristics that distinguish them from other types of mixtures. These include the Tyndall effect, Brownian motion, and the ability to form colloidal gels and colloidal sols.

Tyndall Effect

The Tyndall effect is the scattering of light by particles in a colloidal suspension. This effect is responsible for the blue color of the sky, which is a result of the scattering of sunlight by the atmosphere.

Brownian Motion

Brownian motion is the random movement of particles in a fluid, as a result of their collision with the fast atoms or molecules in the gas or liquid. This phenomenon is observed in colloidal suspensions and is one of the evidence of the particulate nature of matter.

Colloidal Gels and Sols

A colloidal suspension can exist in two states: as a colloidal sol or as a colloidal gel. A colloidal sol is a colloidal suspension in which the dispersed phase is solid and the dispersion medium is liquid. A colloidal gel is a semi-solid system in which particles of a liquid are dispersed in a solid.

Preparation and Uses

Colloidal suspensions can be prepared by various methods, including condensation methods and dispersion methods. They have a wide range of applications in various fields such as medicine, pharmacy, agriculture, and industry.

See Also

• Emulsion
• Aerosol
• Foam (substance)