kolloïdsystem

Kolloïdsystem, also known as a colloidal dispersion or simply a colloid, is a mixture where one substance of fine particles is dispersed evenly throughout another substance. The dispersed-phase particles have a size range typically between 1 nanometer and 1 micrometer. These particles are larger than molecules in a true solution but small enough to remain suspended and not settle out under gravity. The dispersing medium is the substance in which the particles are suspended.

Colloids exhibit properties that are distinct from both true solutions and suspensions. For example, they can scatter light, a phenomenon known as the Tyndall effect, which makes the path of a light beam visible when it passes through the colloid. Colloidal particles are generally electrically charged, which helps to keep them dispersed and prevents aggregation. This charge can be either positive or negative, depending on the nature of the dispersed particles and the medium.

Examples of colloids are widespread in nature and in everyday life. Milk is a common example, where fat globules are dispersed in water. Fog and clouds are colloids of water droplets dispersed in air. Jellies, gels, and emulsions are also types of colloidal systems. The stability of a colloid is often maintained by electrostatic repulsion between the charged particles and by the Brownian motion, which is the random movement of the particles caused by collisions with the molecules of the dispersing medium. Understanding colloids is important in various fields, including chemistry, biology, and materials science.