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Lipase-Catalyzed Reactions in Nonaqueous Media
Published in Sulaiman Al-Zuhair, Hanifa Taher, Supercritical Fluids Technology in Lipase Catalyzed Processes, 2016
Sulaiman Al-Zuhair, Hanifa Taher
Various cations and anions can be used to produce huge number of ILs. The most common are those composed of nitrogen or phosphorus-containing cations such as 1-alkyl-3-methylimidazolium, N-alkylpyridinium, N,N-dialkylpiperidinium, N, N-dialkylpyrrolidinium, tetraalkylammonium, or tetraalkylphosonium; and anions such as chloride, nitrate, hexafluorophosphate, tetrafluoroborate, ethyl sulfate, or bistriflimide, as shown in Figure 5.4 and Table 5.6. The commercially available ILs are those based on 1-butyl-3-methylimidazolium with hexafluorophosphate and tetrafluoroborate anions (Shariati and Peters, 2005; Shariati et al., 2005). The behavior of ILs are almost similar to those of organic solvents, therefore, they can replace volatile organic solvents in many applications, including in enzymatic processes (Earle and Seddon, 2000; Fan and Qian, 2010; Jain et al., 2005).
A Review on the Application of Quaternary Ammonium-Based Ionic Liquids in Mineral Flotation
Published in Mineral Processing and Extractive Metallurgy Review, 2020
Hrushikesh Sahoo, Swagat S. Rath, Bisweswar Das
The physical properties such as viscosity, melting point, and acidity of ILs can be altered by changing the alkyl substituent and halide/halogeno-aluminate of the imidazolium- or pyridinium-based compounds (Gale and Osteryoung 1979). ILs with neutral or weakly coordinating anions such as hexafluorophosphate (PF− 6) and tetrafluoroborate (BF−4) were obtained by Wilkes and Zaworotko (1992) providing a wide range of applications. With due time, research grows toward the synthesis of less toxic ammonium group cations and eradication of halogenated group anions by bistriflimide [(CF3SO2)2N] −.