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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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Author: search.filters.author.Deenadayalu, NirmalaSubject: search.filters.subject.Chemistry, Physical and theoretical

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    Excess molar volumes and partial molar volumes for (propionitrile + an alkanol) at T = 298.15 K and p = 0.1 MPa
    (Elsevier, 2006) Deenadayalu, Nirmala; Bhujrajh, P.
    The excess molar volumes and the partial molar volumes for (propionitrile + an alkanol) at T = 298.15 K and at atmospheric pressure are reported. The hydrogen bonding between the OH NC groups are discussed in terms of the chain length of the alkanol. The alkanols studied are (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-pentanol). The excess molar volume data was fitted to the Redlich–Kister equation The partial molar volumes were calculated from the Redlich–Kister coefficients.
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    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, Deresh
    The 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.
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    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.