Colloidal dispersants in water

Take a spoonful of dirt and vigorously mix it with a glass of water. As soon as you stop mixing, a portion of the dirt drops to the bottom. Any material that is suspended by the fluid motion alone is only in temporary suspension. A portion of the dirt makes a true solution in the water with all of the properties of the above table, but there are some particles, having a diameter roughly between 1 nm and 500 nm, that are suspended in a more lasting fashion. A suspended mixture of particles of this type is called a colloid, or colloidal suspension, or colloidal dispersion .
For colloids or temporary suspensions the phrase dispersed material or the word dispersants describes the material in suspension, analogous to the solute of a solution. The phrase dispersing medium is used for the material of similar function to a solvent in solutions .
As with true solutions, it is a bit of a stretch to consider solids as a dispersing medium or gases as forming a large enough particle to be a colloid, but most texts list some such. A sol is a liquid or solid with a solid dispersed through it, such as milk or gelatin. Foams are liquids or solids with a gas dispersed into them. Emulsions are liquids or solids with liquids dispersed through them, such as butter or gold-tinted glass. Aerosols are colloids with a gas as the dispersing medium and either a solid or liquid dispersant. Fine dust or smoke in the air are good examples of colloidal solid in a gas. Fog and mist are examples of colloidal liquid