Study of Ionic Liquid Microemulsions: Ethylammonium Nitrate/TritonX-100/Cyclohexane

In this study, ionic liquid (IL), specifically ethylammonium nitrate (EAN), was used instead of water to form nonaqueous microemulsions with cyclohexane and the nonionic surfactant Triton X-100 (TX-100). The phase behavior of the ternary system was investigated, and the microemulsions of ionic liquid-in-oil (IL/O) and oil-in-ionic liquid (O/IL) and the bicontinuous microregion were identified through traditional electrical conductivity measurement. The micropolarities of the IL/O microemulsions were determined via UV–Vis spectroscopy with methyl orange as an absorption probe. Results indicated that the polarity of the reverse micelles remained constant but that of the IL/O microemulsions increased when IL pools were formed. Fourier transform infrared spectroscopy was used to study the interaction mechanism between TX-100 and EAN molecules in IL/O microemulsions. We demonstrated that IL/O microemulsions may be promising for application due to the unique features of ILs and microemulsions.

Phase Behaviour of the Microemulsion Systems Formed by the Composite Surfactants Alkyl Polyglucoside and Sodium Dodecyl Sulfate

The phase behavior of microemulsions containing composite surfactants of non-ionic alkyl polyglucoside and anionic sodium dodecyl sulfate was studied by the ∊-β fishlike phase diagram method. In microemulsion systems APG(SDS)/alcohol/alkane/water, there exists an obvious synergistic effect in terms of the composition of the interfacial layer and the solubilization ability. In the interfacial layer the number of surfactant and alcohol molecules notably decrease, resulting in a significant improvement in the solubilization ability of the system. The effects of alcohols, alkanes and salinity on the ∊-β fishlike phase diagrams of APG/SDS/alcohol/alkane/brine microemulsion systems were also discussed.