Emulsions, Microemulsions, and Lyotropic Liquid Crystals

Ionic Liquids can be mixed with surfactants and other solvents to give all types of association colloids that are known with water and other surfactants [28]. Microemulsions can be made as well as different types of lyotropic liquid crystals and emulsions. The Ionic Liquids can play the role of the polar (pseudo-) phase, the apolar one, or of the surfactant. Even two of the three components can be Ionic Liquids. Possible advantages are in the wide temperature range over which such systems show a reasonable stability and the low vapor pressure. Further advantages are the reduced viscosity compared to pure Ionic Liquids (in the cases where the ILs are the inner phase) and the possibility to work in water-free systems [29-31]. 

Microemulsions are microstructured mixtures of oil, water, emulsifiers, and other substances. Since their structures differ in many ways from that of ordinary emulsions, it will be described separately. Liquid crystals (LC) are substances that exhibit special melting characteristics. Further, some surfactant-water-cosurfactant mixtures may also exhibit LC (lyotropic crystal) properties. 

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