mikroemulsions

Mikroemulsions are thermodynamically stable, optically isotropic liquids with a particle size in the range of 20 to 200 nanometers. They consist of oil, water, and a surfactant, and often a cosurfactant. Unlike traditional emulsions which are metastable and require significant energy to form, mikroemulsions form spontaneously upon mixing the components due to the reduction in interfacial tension achieved by the surfactant. The cosurfactant further aids in reducing this tension and stabilizing the structure.

The structure of a mikroemulsion can be described as a dispersion of droplets of one phase (oil or water) within the other, stabilized by a surfactant film. Depending on the relative proportions of oil, water, and surfactant, the mikroemulsion can be oil-in-water (o/w), where oil droplets are dispersed in water, or water-in-oil (w/o), where water droplets are dispersed in oil. Complex bicontinuous structures are also possible.

Mikroemulsions exhibit unique properties such as high surface area, low viscosity, and excellent solubilization capacity for both hydrophobic and hydrophilic substances. These characteristics make them valuable in various applications. In the pharmaceutical industry, they are used for drug delivery, enhancing the bioavailability of poorly soluble drugs. They also find use in cosmetics for formulating creams and lotions, in the food industry for encapsulating flavors and nutrients, and in enhanced oil recovery and as reaction media in chemical synthesis.