ABSTRACT
Different RTILs-Microemulsions Systems .............................................. 223 8.4.1 [Bmim][PF6]/Tx-100/Water ([Bmim][PF6]-in-Water)
Microemulsions ............................................................................ 223 8.4.2 [Bmim][PF6]/TX-100/Water (Water-in-[Bmim][PF6])
Microemulsions ............................................................................ 228 8.4.3 [Bmim][PF6]/Tween-20/Water ([Bmim][PF6]-in-Water)
Microemulsions ............................................................................ 233 8.4.4 [Bmim][BF4]/Tx-100/Cyclohexane Microemulsions .................... 234 8.5 Conclusion ................................................................................................ 236 Acknowledgments ............................................................................................. 237 Symbols and Terminologies .............................................................................. 238 References ......................................................................................................... 238
Room temperature ionic liquids (RTILs), a class of neoteric solvent, have been extensively used as environment friendly “green substitutes” for toxic, hazardous, fl ammable, and volatile organic solvents [1-11]. Ray and Rakshit fi rst reported preparation of RTILs in 1911 [12]. They prepared the nitrite salts of ethylamine, dimethylamine, and trimethylamine, although these salts are spontaneously decompose on standing. A few years latter Walden reported the fi rst useful RTILs in 1914 [13]. He reported the physical properties of ethylammonium nitrate (EAN), which has a melting point of 12°C. Cations and anions of RTILs are generally organic and inorganic in nature, respectively. In RTILs coulombic interactions between ions are prominent in contrast to dipolar or multipolar interaction in volatile organic compounds (VOCs). By changing substituents in the cation or in the anion components various RTILs can be prepared for different purposes. By fi ne-tuning the cations and anions certain bulk properties like viscosity, conductivity, and density of RTILs can be changed. The key feature of RTILs is the nonvolatile nature and RTILs do not contribute VOCs in the global atmosphere. So it is better to use RTILs rather than VOCs for industrial use. Most of the RTILs have some common properties such as negligible vapor pressure, broad liquidous temperature range (−96°C to ∼300°C), high conductivity, wide electrochemical windows, and ability to solvate various organic or inorganic species.
