Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. AN emulsion is two immiscible liquids mixed together (by shaking for example) with small droplets of one liquid dispersed (separated and distributed throughout the space) in the other liquid. THis dispersion is usually not stable and all the droplets will clump together over time and forms two layers. BEcause of the immiscibility, the emulsion is classified according to the chemical nature of the liquids such as oil-in-water (O/W), e.G. Micelles, or water-in-oil (W/O), inverted micelles, and sometimes with complex structure such as water-in-oil-in-water (W/O/W). THese classical types of emulsions can be stabilized from coalescence (i.E. Preventing the droplets from clumping together) by the presence of surfactant molecules, of which part of the molecular structure is soluble in water, and the other part is soluble in oil-like solvents (Fig 1A).