Generally, here one phase (solid) is mixed in other phase (liquid). the classification in the most general terms happens on the size of the particles
Very Small, 1nm, its solution
small, 1nm to i micron, it stable , the its a colloid
small to large, if the particle settle, then its called as coarse dispersion (suspension)
Generally it is dispersion or suspension, but the paricle should be in such size or modifed in such a way that it will suspend for long time, say 6 months. if it is in nano size it normally see as a solution but it will also get agglomorated and suspended depending on the effect of modification. microsize mainly comes normally as suspension. dispersion is a mix of water insoliable solid suspended in water by suitable modification or without modification by sie reduction ( In most of the cases modification is done)
The addition of a fluid which could be organic or inorganic will either lead to dispersion or suspension. Dispersion means that particles are stable and they do not settle down. But as far as I know about emulsion, it occurs when some emulsifier causes separation of one phase from the other.
Solution: the solute dissolves in the solvent. The dissolved particles cannot be seen with a microscope. Example: sea water.
Suspension: the solid does not dissolve in the solvent and if allowed to settle will separate out; the mixture is heterogeneous, .i.e. a mixture of solid and liquid. A dispersion is a type of suspension which does not separate quickly, typically dispersions are made in high viscosity solvents such as oils so separation is slow. Within suspensions we find the following subsets:
Colloid: a substance microscopically dispersed in a solvent (particles 1- 1000nm). Colloids normally comprise a solid dispersed in a solvent. In a colloidal suspension the particles are typically visible under a microscope. Colloids typically give rise to the Tyndall effect. Micelles are examples of colloids in which surfactant molecules (greasy one end and ionic the other) are dispersed in a liquid. Soaps often form micelles in water.
Emulsion: This is another form of suspension in which two immiscible liquids are used, e.g. vinaigrette dressing (oil/water mix) A third agent known as an emulsifier may stabilise the mixing of the two liquids and is typically a surfactant capable of binding to both water and oil phases.
Wikipedia has good descriptions and examples of these phenomena. Hope that helps.
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I agree with definitions of Jeremy, but the term dispersion was not defined. Dispersion, generically, It means that one phase (gas, liquid or solid) is spread in a continuous phase, a gas or liquid phase. Emulsion, aerosol, suspension, coloidal suspension, etc are all dispersions.
That's it.
Discussion shows that unfortunately terms dispersion, suspension, emulsion are misused making presentation and understanding of research difficult.
In addition dispersions with solids as continuous phase also exist, e.g. pumice.
Further, dispersions are all thermodynamically unstable, however, maybe kinetically stable or unstable.
Colloids maybe dispersions or solutions. The latter include the so called microemulsions.
Usually, when solid particles are added to liquid, the goal is to disperse them to maximum uniformity, so as to maintain stability. The resulting is a dispersion.
Hi, in mining industry a mixture of solid and liquid is named slurry.
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