Research Publications (Applied Sciences)
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Item Excess molar volumes of binary mixtures (an ionic liquid + water) : A review(Elsevier, 2015-03) Bahadur, Indra; Singh, Sangeeta; Redhi, Gan G.; Venkatesu, Pannuru; Letcher, Trevor M.This review covers recent developments in the area of excess molar volumes for mixtures of {ILs (1) + H2O (2)} where ILs refers to ionic liquids involving cations: imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium and ammonium groups; and anions: tetraborate, triflate, hydrogensulphate, methylsulphate, ethylsulphate, thiocyanate, dicyanamide, octanate, acetate, nitrate, chloride, bromide, and iodine. The excess molar volumes of aqueous ILs were found to cover a wide range of values for the different ILs (ranging from −1.7 cm3 · mol−1 to 1.2 cm3 · mol−1). The excess molar volumes increased with increasing temperature for all systems studied in this review. The magnitude and in some cases the sign of the excess molar volumes for all the aqueous ILs mixtures, apart from the ammonium ILs, were very dependent on temperature. This was particularly important in the dilute IL concentration region. It was found that the sign and magnitude of the excess molar volumes of aqueous ILs (for ILs with hydrophobic cations), was more dependent on the nature of the anion than on the cation.Item Application of the extended real associated solution theory to excess molar enthalpies and excess molar volumes of binary mixtures of (benzene or 1-alkanol + quinoline)(Elsevier, 2005-06-01) Deenadayalu, Nirmala; Letcher, Trevor M.Excess molar enthalpies and excess molar volumes of binary mixtures of (benzene or methanol or ethanol or 1-propanol or 1- butanol+quinoline) as a function of composition at a pressure of 1 atm and a temperature of 298.15 K have been used to test the Extended Real Solution Theory, ERAS, of nonelectrolyte solutions. The ERAS theory accounts for free volume effects according to the Flory–Patterson theory and for association effects: self and crossassociation between the molecules involved. The ERAS theory results for the binary mixtures (benzene or an alkanol+quinoline) indicates strong hydrogen bonding effects between unlike molecules given by the predicted hydrogen bonding energy between two dissimilar compounds. Comparison is also made between the chemical and physical contribution to the ERAS theory. The Extended Real Associated Solution theory describes the published Vm E data better than the published Hm E data.