What’s a Colloid?

Print anything with Printful



Colloids are mixtures where one substance is dispersed evenly into another without changing their structure. They can exist in all states of matter and have a uniform distribution of all constituent parts. Surfactants are used to maintain the dispersion of immiscible components. Examples of colloids include milk, fog, and toothpaste.

A colloid is the end result of dispersing one substance evenly and microscopically into another without any change in the structure of either. Colloids are distinct from other combinations such as solutions due to the fact that none of the constituent parts of the union dissolve or undergo structural changes during dispersion. Colloids can exist in combinations of all states of matter including gaseous, liquid and solid compounds. In an emulsified state, colloidal compounds can consist of one or more immiscible constituents in which the surfactants maintain a uniform distribution of the individual parts. Some well-known examples of colloids are milk and fog.

Mixtures or blends of different materials and substances exist in a variety of forms. In most, one or more of the individual parts of the mixture undergo some sort of physical or chemical change. Unlike combinations such as solvents and alloys, colloidal mixtures feature a uniform distribution of all constituent parts in their original, unchanged form. This means that colloids provide the individual characteristics of all their parts and not a reactive combination of qualities. In this way the active ingredients can be suspended in inert carrier media without modifying or altering their characteristics.

Colloidal mixtures consist of two distinct parts: a dispersed phase or substance and a dispersion medium. Milk, for example, is a colloid consisting of a dispersion phase of liquid butterfat distributed in an aqueous-based dispersion medium. Colloids can consist of combinations of all states of matter with common unions including liquid/air mixtures such as fog and mist and solid/air unions such as masses of smoke or clouds. Other common combinations include liquid/gas blends such as whipped cream, liquid/solid gel combinations such as gelatin, and solid/liquid dispersions including blood and inks. Cranberry decorative glass is an example of a solid/solid colloid and is a combination of red glass and gold chloride.

The individual parts of liquid/liquid colloids are not always miscible or miscible and would gradually separate after combination if no additional additives were introduced. These additives are known as surfactants and alter the surface tension characteristics of the mixture which encourages the immiscible components to remain uniformly dispersed. Milk is one of the best known examples of these unions or emulsions. Colloids can also be formulated to exhibit unstable, fractional qualities that allow them to flow when exposed to stress and then regain cohesion once the stress ceases. An example of this phenomenon is toothpaste, which flows when the tube is squeezed and therefore remains stable on the toothbrush.




Protect your devices with Threat Protection by NordVPN


Skip to content