Ionic liquid-based surfactants micellized

Surfactants have a unique long-chain molecular structure composed of a hydrophilic head and hydrophobic tail. Based on the nature of the hydrophilic part surfactants are generally categorized as anionic, non-ionic, cationic, and zwitter-ionic. They all have a natural tendency to adsorb at surfaces and interfaces when added in low concentration in water. Surfactant absorption/desorption at the vapor-liquid interface alters the surface tension, which decreases continually with increasing concentrations until the critical micelle concentration (CMC), at which micelles (colloid-sized clusters or aggregates of monomers) start to form is reached (Manglik et al. 2001 Hetsroni et al. 2003c). 

Internal Phase Composition As with the continuous phase, the internal phase properties also influence the properties of the ELM. Ionic strength, pH, and the presence of organic species will impact on the stability of the ELM. Emulsion liquid membranes work on the basis that the polar substances (usually high concentrations of acid or base) contained in the internal phase are impermeable to the membrane phase. However, the presence of the surfactant can cause the uptake of these compounds by the formation of reverse micelles [97]. 

Generally, amphiphilic molecules self-assemble to form micelle, microemulsion, lyotropic liquid crystal and vesicle. Moreover, long-chain ILs can act as ionic surfactants and form similar self-assembly in water or oil. Qiu et al. summarized the studies of IL based microemulsions from the p>erspective of the role of ILs (Qiu Texter, 2008). ILs participated in the formation of the microemulsions, in which ILs replaced oil, water or surfactants. Hao et al. reviewed the self-assembled structures (such as micelles, microemulsions, liquid crystals and vesicle) in ILs, which acted as the solvent (Hao Zemb, 2007). In this p>art, we summarized the IL based organized assemblies, in which IL participated in the formation of micelles, microemulsions, vesicles and liquid crystals rather than acted as solvents. 

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