[4] With respect to molecular diffusion, dispersion occurs as a result of an unequal concentration of the introduced material throughout the bulk medium.
With respect to convection, variations in velocity between flow paths in the bulk facilitate the distribution of the dispersed material into the medium.
The molecules in a drop of food coloring added to water will eventually disperse throughout the entire medium, where the effects of molecular diffusion are more evident.
[6] A full quantification of dispersion would involve the size, shape, and number of particles in each agglomerate or aggregate, the strength of the interparticle forces, their overall structure, and their distribution within the system.
A colloid is a heterogeneous mixture where the dispersed particles have at least in one direction a dimension roughly between 1 nm and 1 μm or that in a system discontinuities are found at distances of that order.
Unlike solutions and colloids, if left undisturbed for a prolonged period of time, the suspended particles will settle out of the mixture.
Due to the various reported definitions of solutions, colloids, and suspensions provided in the literature, it is difficult to label each classification with a specific particle size range.
The International Union of Pure and Applied Chemistry attempts to provide a standard nomenclature for colloids as particles in a size range having a dimension roughly between 1 nm and 1 μm.
The fat molecules suspended in milk provide a mode of delivery of important fat-soluble vitamins and nutrients from the mother to newborn.
[10] The mechanical, thermal, or enzymatic treatment of milk manipulates the integrity of these fat globules and results in a wide variety of dairy products.
[13] Several different solutions to seawater intrusion in coastal aquifers have been proposed, including engineering methods of artificial recharge and implementing physical barriers at the sea boundary.