Mangosuthu University of Technology (MUT)
Nkululeko N, Infinite dilution activity coefficients and thermodynamic properties.pdf (818.01 kB)

Infinite dilution activity coefficients and thermodynamic properties of selected organic solutes and water dissolved in 1, 6-hexanediol

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journal contribution
posted on 2022-01-10, 13:05 authored by Nkululeko Nkosi, Kaniki Tumba, Peterson Ngema, Suresh Ramsuroop
The experimental activity coefficients (c1 13) and gas-to-liquid partition coefficients (KL) at infinite dilution for 34 organic solutes and water were determined in 1.6-hexanediol (HDO) by the gas–liquid chromatog?raphy technique (GLC) in the temperature range from (323.15 to 353.15) K. Fundamental thermodynamic functions such as excess partial molar enthalpy (DHE;ð1Þ i ), excess partial molar Gibbs energy, (DGE;1 i ) and entropy, (TrefDSE;1 i ) at infinite dilution were calculated from experimental values of c1 13. Reported data were discussed in terms of solvent-solute interactions, heat effects and mixing spontaneity. Selectivity (S1 ij ) and capacity (k 1 j ) related to different separation problems were calculated from c1 13 data and com?pared to the literature values for selected ionic liquids (ILs), deep eutectic solvents (DESs) and industrial solvents. New data reported in this study suggest that HDO may be proposed as an alternative solvent for the separation of alkanes-pyridine and alkanes-thiophene systems. Furthermore, it was found that add?ing a hydrogen bond acceptor to HDO enhances its performance as a separation solvent.


This study has been supported by the Durban University of Technology and Mangosuthu University of Technology. Author N. Nkosi wishes to thank the Council for Scientific and Industrial Research (CSIR) in South Africa for the financial support while undertaking this research project.