WIKO-Wiki: S
Suspension
A suspension is a heterogeneous mixture of a solid and a liquid medium in which the solid does not dissolve completely but is distributed in small particles in the medium. The particles have a size of 1 to 1000 micrometers and cannot be seen with the naked eye. Examples of suspensions are sand in water or dust in air.
An important property of suspensions is their stability. As the particles are heavier than the liquid medium, they tend to settle to the bottom of the vessel. This process is called sedimentation. If the suspension remains undisturbed, the particles can accumulate to form a dense layer at the bottom of the vessel. To avoid this, suspensions are often maintained with a stirrer or by shaking.
Suspensions can be separated by filtration or centrifugation. In filtration, the suspension is pressed through a filter that retains the particles while the liquid medium passes through. In centrifugation, the suspension is centrifuged in a centrifugal field, causing the particles to settle at the bottom of the vessel.
Suspensions are used in many applications, such as in medicine, in the food industry and in the production of paints and pigments. In medicine, suspensions can be used as drugs to enable the slow and controlled release of active ingredients. Overall, suspension is an important type of heterogeneous mixture that is used in many applications. Knowledge of the properties and possible uses of suspensions is important in order to optimize their use and avoid undesirable effects.
