IntroductionRoom temperature ionic liquids (RTILs), an interesting class of tunable and designer solvents with the extremely low vapor pressure have been extensively used as a potential replacement for toxic, hazardous, flammable and highly volatile organic solvents (VOSs) (Welton, 1999;Rogers and Seddon, 2002 Figure 1)), and are liquids at ambient or far below ambient temperatures. In fact, the asymmetry of the cation is believed to be responsible for the low melting temperatures. Based on the solubility of ILs in water, ILs can be divided into two categories: hydrophobic (water immiscible) and hydrophilic (water miscible). This water miscibility generally depends on the anions of ILs. ILs have many attractive physicochemical properties such as negligible vapor pressure, multiple solvation interactions with organic and inorganic compounds (Anderson et al., 2002), excellent chemical and thermal stability (Kosmulski et al., 2004), high ionic conductivity and a wide liquid temperature ranges which draw the growing interest in both industrial and academic research laboratories. Most importantly, the properties regarded as the viscosity, hydrophobicity, density and solubility of ILs can be tuned by selecting different combinations of cations and anions, to customize ILs for specific demands. During the last decade, the interest in the ILs has increased significantly because of their potential as solvents and/or (co)solvents and/or reagents in a wide range of applications, including chemical engineering (separation, extraction and membranes) (Visser et al., 2001;Anderson and Armstrong, 2005)