SUSPENSION (CHEMISTRY)

In chemistry, a 'suspension' is a heterogenous mixture in which the particles of at least one component are larger than 1μm (1000nm) in at least one dimension, larger than colloidal particles.^[1] Unlike colloids, suspensions will eventually settle. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid in which the suspended particles are smaller and do not settle.^[2] In a solution, the dissolved substance does not exist as a solid and the two are homogeneously mixed.

★ 'Definition:' A suspension is a heterogenous mixture in which the internal phase is dispersed throughout the external phase through mechanical agitation, with the use of certain excipients or suspending agents.

★ 'Classification': They are classified on the basis of the dispersed phase and the dispersion medium, where the former is essentially solid while the latter may either be a solid, a liquid or a gas. They are classified on the basis of dosage form which may either be oral, topical or parental.

Contents

Common examples

See also

References

Common examples

★ Mud or muddy water, is where soil, clay, or silt particles are suspended in water.

★ Flour suspended in water, as pictured to the right.

★ Paint

★ Chalk powder suspended in water.

★ Dust particles suspended in air.

See also

★ colloid

★ sol

★ emulsion

★ turbidity

★ settleable solids

★ sediment transport

★ solution

References

1. Chemistry: Matter and Its Changes, 4th Ed. by Brady, Senese, ISBN 0471215171
2. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2007, Columbia University Press.