often used to quantify the degree of dispersion, with suspensions possessing a high absolute value of zeta potential being considered as well-dispersed. Types of dispersions A solution describes a homogeneous mixture where the dispersed particles will not settle if the solution is left undisturbed for a prolonged period of time. 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. A suspension is a heterogeneous dispersion of larger particles in a medium. Unlike solutions and colloids, if left undisturbed for a prolonged period of time, the suspended particles will settle out of the mixture. Although suspensions are relatively simple to distinguish from solutions and colloids, it may be difficult to distinguish solutions from colloids since the particles dispersed in the medium may be too small to distinguish by the human eye. Instead, the Tyndall effect is used to distinguish solutions and colloids. 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. In addition to the classification by particle size, dispersions can also be labeled by the combination of the dispersed phase and the medium phase that the particles are suspended in. Aerosols are liquids dispersed in a gas, sols are solids in liquids, emulsions are liquids dispersed in liquids (more specifically a dispersion of two immiscible liquids), and gels are liquids dispersed in solids. Examples of dispersions Milk is a commonly cited example of an emulsion, a specific type of dispersion of one liquid into another liquid where to two liquids are immiscible. The fat molecules suspended in milk provide a mode of delivery of important fat-soluble vitamins and nutrients from the mother to newborn. The mechanical, thermal, or enzymatic treatment of milk manipulates the integrity of these fat globules and results in a wide variety of dairy products. Oxide dispersion-strengthened alloy (ODS) is an example of oxide particle dispersion into a metal medium, which improves the high temperature tolerance of the material. Therefore these alloys have several applications in the