Research Publications (Applied Sciences)
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Item Synthesis, characterization and thermophysical properties of ionic liquid N-methyl-N-(2′,3′-epoxypropyl)-2-oxopyrrolidinium chloride and its binary mixtures with water or ethanol at different temperatures(Elsevier, 2016) Vasanthakumar, Arumugam; Bahadur, Indra; Redhi, Gan G.; Gengan, Robert Moonsamy; Anand, KrishnanA novel ionic liquid, namely, N-methyl-N-(2′,3′-epoxypropyl)-2-oxopyrrolidiniumchloride [Epmpyr]+[Cl]− was synthesized and characterized by different techniques such as NMR (1H and 13C), FTIR, and elemental analysis. The water content of the ionic liquid was checked by Karl Fisher titration. Further, the density, ρ, and speed of sound, u, were measured for the above ionic liquid and the corresponding binary systems with water or ethanol at different temperatures ranging from (293.15 to 313.15) K. The derived thermodynamic properties for instance excess molar volumes, VE m isentropic compressibility, κs, and deviation in isentropic compressibility, Δκs, were investigated from the density and speed of sound data, respectively. It is noted that density and speed of sound of the ionic liquid and its binary mixtures were decreased with increase in temperature, whereas excess molar volume, isentropic compressibility, and deviation in isentropic compressibility values increased. Derived properties such as excess molar volumes, and deviation in isentropic compressibility data were fitted to the Redlich-Kister polynomial equation. The measured and calculated data were interpreted in terms of intermolecular interfaces and structural effects between similar and dissimilar molecules upon mixing.Item Industrial application of ionic liquids for the recoveries of spent paint solvent(Elsevier, 2016) Moodley, Kandasamy; Mabaso, Mbongeni Hezekia; Bahadur, Indra; Redhi, Gan G.The recovery of industrially valuable organic solvents from liquid waste, generated in chemical processes, is economically crucial to countries which need to import organic solvents. In view of this, the main objective of this study was to determine the ability of selected ionic liquids, namely, 1-ethyl-3-methylimidazolium ethylsulphate, [EMIM][ESO4] and 1-ethyl-3-methylpyridinium ethylsulphate, [EMpy][ESO4] to recover aromatic components from spent paint solvents. Preliminary studies done on the liquid waste, received from a paint manufacturing company, showed that the aromatic components were present in the range of (6–21)% by volume. The separation of the aromatic components was performed with the ionic liquids listed above. The phases, resulting from the separation of the mixtures, were analysed with a gas chromatograph (GC) coupled to a FID detector. Chromatograms illustrate that the chosen ZB-Wax-Plus column gave excellent separation of all components of interest from the mixtures, including the isomers of xylene. The concentrations of aromatics recovered from the spent solvents were found to be in the % ranges of (13 − 33) and (23–49), respectively for imidazolium and pyridinium based ionic liquids. These results also show that there is a significant correlation between π-character of ionic liquids and the level of extraction. It is therefore concluded that ionic liquids have the potential for macro-scale recovery of re-useable solvents present in liquid waste emanating from paint manufacture.Item Apparent molar volume and apparent molar isentropic compressibility for the binary systems {methyltrioctylammoniumbis(trifluoromethylsulfonyl)imide + ethyl acetate or ethanol} at different temperatures under atmospheric pressure(Elsevier, 2013-05-20) Bahadur, Indra; Deenadayalu, NirmalaThe density (d) and speed of sound (u) for the binary systems were measured at 298.15, 303.15, 308.15, and 313.15 K under atmospheric pressure. The binary systems contained the ionic liquid (IL): methyltrioctylammoniumbis(trifluoromethylsulfonyl)imide ([MOA]+[Tf2N]−). The binary systems were ([MOA]+[Tf2N]− + ethyl acetate or ethanol). The apparent molar volume, Vφ, and the apparent molar isentropic compressibility, kφ, have been evaluated from the experimental density and speed of sound data, respectively. A Redlich–Mayer equation was fitted to the apparent molar volume and apparent molar isentropic compressibility data. The partial molar volume, View the MathML source, and partial molar isentropic compressibility, View the MathML source, of the binary mixtures have also been calculated at each temperature. The partial molar volume indicates that the intermolecular interactions for (IL + ethanol) are stronger than for (IL + ethyl acetate) at all temperatures and View the MathML source for both systems increases with an increase in temperature. The values of the infinite dilution apparent molar expansibility, View the MathML source, decreases with an increase in temperature. The isentropic compressibilities, ks, increases with an increase in temperature for both binary systems. Positive View the MathML source, for both binary systems can be attributed to the predominance of solvent intrinsic compressibility over the solute intrinsic effect.Item Ternary excess molar volumes of {methyltrioctylammonium bis(trifluoromethylsulfonyl)imide + ethanol + methyl acetate, or ethyl acetate} systems at T = (298.15, 303.15, and 313.15) K(Elsevier, 2010-01-28) Gwala, Nobuhle V.; Deenadayalu, Nirmala; Tumba, Kaniki; Ramjugernath, DereshThe activity coefficient at infinite dilution for 30 solutes: alkanes, alkenes, cycloalkanes, alkynes, ketones, alcohols, and aromatic compounds was determined from gas–liquid chromatography (glc) measurements at three temperatures (303.15, 313.15, and 323.15) K. The ionic liquid: trioctylmethylammonium bis(trifluoromethylsulfonyl)imide, was used as the stationary phase. For each temperature, values were determined using two columns with different mass percent packing of the ionic liquid. The selectivity value was calculated from the to determine the suitability of the solvent as a potential entrainer for extractive distillation in the separation of an hexane/benzene mixture, indicative of a typical industrial separation problem for benchmarking purposes.