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Research Publications (Applied Sciences)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/213

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Subject: search.filters.subject.Speed of sound

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    Synthesis and characterization of 2′,3′-epoxy propyl-N-methyl-2-oxopyrrolidinium salicylate ionic liquid and study of its interaction with water or methanol
    (Royal Society of Chemistry, 2016) Vasanthakumar, Arumugam; Bahadur, Indra; Redhi, Gan G.; Gengan, Robert Moonsamy
    Important physico-chemical properties of ionic liquids (ILs) can be manipulated by adjusting the nature of the cation or anion. These properties are exploited in applications such as organic synthesis, catalysis and electrochemical processes to mention a few. In this work, the novel pyrrolidone ionic liquid N-(2′,3′-epoxypropyl)-N-methyl-2-oxopyrrolidinium salicylate [EPMpyr]+[SAL]− was synthesized using two steps and characterized. The temperature dependent density and speed of sound for ionic liquid, methanol, water, and their corresponding binary mixtures of {IL (1) + methanol or water (2)} were measured over the entire range of mole fractions at temperatures from T = (293.15 to 313.15) K in steps of 5 K, under atmospheric pressure. The calculated thermodynamic properties such as excess molar volume VEm, isentropic compressibility ks, intermolecular free length Lf, and deviation in isentropic compressibility Δks, were derived from the investigated density and speed of sound data. The resulting experimental data for excess molar volumes VEm, intermolecular free length Lf, and deviation in isentropic compressibility Δks, were well fitted to the Redlich–Kister polynomial equation. The effect of temperature and concentration on thermophysical properties was also provided.
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    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, Krishnan
    A 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.
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    Density and speed of sound of 1-ethyl-3-methylimidazolium ethyl sulphate with acetic or propionic acid at different temperatures
    (Elsevier, 2014-11) Singh, Sangeeta; Bahadur, Indra; Redhi, Gan G.; Ramjugernath, Deresh; Ebenso, Eno, E.
    In this work, new density, ρ, and speed of sound, u, were measured for IL, acetic acid, propionic acid, and their binary systems {IL (x1) + acetic or propionic acid (x2)} at 293.15, 298.15, 303.15, 308.15 and 313.15 K under at-mospheric pressure. The IL used in this study was 1-ethyl-3-methylimidazolium ethyl sulphate ([EMIM]+[EtSO4]−). The derived properties such as excess molar volumes, Vm, isentropic compressibility, κs, and deviation in isentropic compressibility, Δκs, were calculated using experimental density and speed of sound data, respectively. Derived properties such as excess molar volumes, Vm, and deviation in isentropic com-pressibility, Δκs, data were fitted to the Redlich–Kister polynomial equation. The measured and calculated data were interpreted on the basis of intermolecular interactions and structural effects between like and unlike mol-ecules upon mixing.
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    Densities, speeds of sound, and refractive indices for binary mixtures of 1-butyl-3-methylimidazolium methyl sulphate ionic liquid with alcohols at T = (298.15, 303.15, 308.15, and 313.15) K
    (Elsevier, 2012-09-24) Singh, Sangeeta; Aznar, Martin; Deenadayalu, Nirmala
    Experimental densities, speeds of sound, and refractive indices of the binary mixtures {1-butyl-3-methylimidazolium methylsulphate ([BMIM]+[MeSO4]−) + methanol, or 1-propanol, or 2-propanol, or 1-butanol} were measured over the whole range of composition at T = (298.15, 303.15, 308.15, and 313.15) K. From the experimental data, excess molar volumes, excess isentropic compressibilities, deviation in refractive indices and molar refractions were calculated. The excess molar volumes, change in isentropic compressibilities, and deviation in refractive indices were fitted by the Redlich–Kister smoothing polynomial. The Lorentz–Lorenz equation was applied to correlate the volumetric properties and predict the density or the refractive index of the binary mixtures. Results for these quantities have been discussed in terms of intermolecular interactions between the components of the mixtures. For all the systems studied, the excess molar volume and excess isentropic compressibility are negative, while the change in refractive index on mixing is always positive over the entire composition range and at all temperatures.