Journal of Thermal Analysis and Calorimetry

, Volume 121, Issue 3, pp 1129–1137 | Cite as

Ethylammonium alkanoate-based ionic liquid + water mixtures

A calorimetric and volumetric study at 298.15 K
  • Marianna Usula
  • Natalia V. Plechkova
  • Alessandra Piras
  • Silvia Porcedda


A systematic study of a series of room-temperature ionic liquids, belonging to the ethylammonium alkanoate family (EAX), was carried out at 298.15 K and 0.1 MPa with the aim of investigating the effect of the anionic chain length on some thermophysical properties and their behaviour in water (W), over the whole mole fraction range. The determination of Gutmann acceptor numbers for the pure EAX by using 31P NMR spectroscopy allowed us to obtain a quantitative measure of Lewis acidity. Experimental densities, ρ, were used to calculate molar volumes, V m, and excess molar volumes, V E. Complementary information was obtained by isothermal titration calorimetry that provided the values of the heat of mixing, H E, and the excess partial molar enthalpies of each component, \( \bar{H}_{1}^{E} \) and \( \bar{H}_{2}^{E} \). The density values of pure EAX samples decrease as the alkyl chain length of the anion increases. Moderate negative V E and H E values were found for each EAX + W system, indicating the presence of attracting interactions between the constituents.


Ethylammonium Methanoate Propanoate Butanoate Excess molar volume Enthalpy 



This research was financially supported by PRIN (2009 WHPHRH). M. U. gratefully acknowledges Sardinia Regional Government for the financial support of her PhD scholarship (P.O.R. Sardegna F.S.E. 2007-2013). M. U. and S. P. express their gratitude to the Istituto per i Processi Chimico-Fisici, IPCF-CNR, Pisa, for allowing the use of calorimetric instrumentations and methods within the collaboration agreement between DSCG and IPCF. M.U and S. P. wish to thank Enrico Matteoli, Francesca Mocci and Flaminia Cesare Marincola for insightful comments. M. U. wishes to thank Kenneth R. Seddon for the acceptance in Queen’s University Ionic Liquid Laboratories (QUILL) for the Erasmus PlaceDoc and for helpful discussion. N. P. was supported by the industrial advisory board of QUILL. M. U. thanks Fergal Coleman from QUILL for his assistance with the Gutmann Acceptor Number studies.

Supplementary material

10973_2015_4753_MOESM1_ESM.doc (109 kb)
Supplementary material 1 (DOC 109 kb)


  1. 1.
    Wasserscheid P, Welton T. Ionic liquids in synthesis. Weinheim: VCH Wiley; 2002.CrossRefGoogle Scholar
  2. 2.
    Plechkova NV, Seddon KR. Applications of ionic liquids in the chemical industry. Chem Soc Rev. 2008;37:123–50.CrossRefGoogle Scholar
  3. 3.
    Attri P, Venkatesu P, Kumar A, Byrne N. A protic ionic liquid attenuates the deleterious actions of urea on α-chymotrypsin. Phys Chem Chem Phys. 2011;13:17023–6.CrossRefGoogle Scholar
  4. 4.
    Yue Y, Jiang X-Y, Yu J-G, Tang K-W. Enantioseparation of mandelic acid enantiomers in ionic liquid aqueous two-phase extraction systems. Chem Pap. 2013;68:465–71.Google Scholar
  5. 5.
    Hernoux-Villière A, Lévêque J-M, Kärkkäinen J, Papaiconomou N, Lajunen M, Lassi U. Task-specific ionic liquid for the depolymerisation of starch-based industrial waste into high reducing sugars. Catal Today. 2014;223:11–7.CrossRefGoogle Scholar
  6. 6.
    Suzuki T, Kono K, Shimomura K, Minami H. Preparation of cellulose particles using an ionic liquid. J Colloid Interface Sci. 2014;418:126–31.CrossRefGoogle Scholar
  7. 7.
    Seddon KR. Review ionic liquids for clean technology. J. Chem. Tech. Biotechnol. 1997;68:351–6.CrossRefGoogle Scholar
  8. 8.
    Greaves TL, Drummond CJ. Protic ionic liquids: properties and applications. Chem Rev. 2008;108:206–37.CrossRefGoogle Scholar
  9. 9.
    Rogers RD, Seddon KR. Ionic liquids-Solvents of the future? Science. 2003;302:792–3.CrossRefGoogle Scholar
  10. 10.
    Welton T. Ionic liquids in catalysis. Coord Chem Rev. 2004;248:2459–77.CrossRefGoogle Scholar
  11. 11.
    Gutmann V. Empirical parameters for donor and acceptor properties of solvents. Electrochim Acta. 1976;21:661–70.CrossRefGoogle Scholar
  12. 12.
    Gutmann V. The donor acceptor approach to molecular interaction. New York: Plenum; 1978.CrossRefGoogle Scholar
  13. 13.
    Rodrìguez H, Brennecke JF. Temperature and composition dependence of the density and viscosity of binary mixtures of water + ionic liquid. J Chem Eng Data. 2006;51:2145–55.CrossRefGoogle Scholar
  14. 14.
    García-Miaja G, Troncoso J, Romaní L. Excess enthalpy, density, and heat capacity for binary systems of alkylimidazolium-based ionic liquids + water. J. Chem. Thermodyn. 2009;41:161–6.CrossRefGoogle Scholar
  15. 15.
    Porcedda S, Marongiu B, Schirru M, Falconieri D, Piras A. Excess enthalpy and excess volume for binary systems of two ionic liquids + water. J Therm Anal Calorim. 2010;103:29–33.CrossRefGoogle Scholar
  16. 16.
    Navarro P, Larriba M, Beigbeder J-B, Garcìa L, Rodrìguez F. Thermal stability and specific heats of [bpy][BF4] + [bpy][Tf2 N] and [bpy][BF4] + [4bmpy][Tf2 N] mixed ionic liquid solvents. J Therm Anal Calorim. 2015;119:1235–43.CrossRefGoogle Scholar
  17. 17.
    Sharma VK, Kataria J, Bhagour S. Thermodynamic investigations of 1-ethyl-3-methylimidazolium tetrafluoroborate and cycloalkanone mixtures: excess molar volumes, excess molar isentropic compressibilities, excess molar enthalpies, and excess heat capacities. J Therm Anal Calorim. 2014;118:431–47.Google Scholar
  18. 18.
    Sharma VK, Solanki S, Bhagour S. Excess molar enthalpies of binary and ternary mixtures. J Therm Anal Calorim. 2015;119:1293–302.CrossRefGoogle Scholar
  19. 19.
    Chhotaray PK, Gardas RL. Thermophysical properties of ammonium and hydroxylammonium protic ionic liquids. J. Chem. Thermodyn. 2014;72:117–24.CrossRefGoogle Scholar
  20. 20.
    Anouti M, Caillon-Caravanier M, Dridi Y, Jacquemin J, Hardacre C, Lemordant D. Liquid densities, heat capacities, refractive index and excess quantities for protic ionic liquids + water binary system. J. Chem. Thermodyn. 2009;41:799–808.CrossRefGoogle Scholar
  21. 21.
    Iglesias M, Torres A, Gonzalez-Olmos R, Salvatierra D. Effect of temperature on mixing thermodynamics of a new ionic liquid: {2-Hydroxy ethylammonium formate (2-HEAF) + short hydroxylic solvents}. J. Chem. Thermodyn. 2008;40:119–33.CrossRefGoogle Scholar
  22. 22.
    Greaves TL, Ha K, Muir BW, Howard SC, Weerawardena A, Kirby N, et al. Protic ionic liquids (PILs) nanostructure and physicochemical properties: development of high-throughput methodology for PIL creation and property screens. Phys Chem Chem Phys. 2015;117:2357–65.CrossRefGoogle Scholar
  23. 23.
    Greaves TL, Weerawardena A, Fong C, Krodkiewska I, Drummond CJ. Protic ionic liquids: solvents with tunable phase behavior and physicochemical properties. J. Phys. Chem. B. 2006;110:22479–87.CrossRefGoogle Scholar
  24. 24.
    Waichigo MM, Danielson ND. Ethylammonium formate as an organic solvent replacement for ion-pair reversed-phase liquid chromatography. J Chromatogr Sci. 2006;44:607–14.CrossRefGoogle Scholar
  25. 25.
    Waichigo MM, Danielson ND. Comparison of ethylammonium formate to methanol as a mobile-phase modifier for reversed-phase liquid chromatography. J Sep Sci. 2006;29:599–606.CrossRefGoogle Scholar
  26. 26.
    Waichigo MM, Riechel TL, Danielson ND. Ethylammonium acetate as a mobile phase modifier for reversed phase liquid chromatography. Chromatographia. 2004;61:17–23.CrossRefGoogle Scholar
  27. 27.
    Bicak N. A new ionic liquid: 2-hydroxy ethylammonium formate. J Mol Liq. 2005;116:15–8.CrossRefGoogle Scholar
  28. 28.
    Marsh KN, Richards AE. Excess volumes of ethanol + water mixtures at 10-K intervals from 278.15 K to 338.15 K. Aust J Chem. 1980;33:2121–32.CrossRefGoogle Scholar
  29. 29.
    Porcedda S, Usula M, Marongiu B. Physical–chemical properties of ionic liquid-containing mixtures. In: Caminiti R, Gontrani L, editors. The structure of ionic liquids, soft and biological matter. Switzerland: Springer; 2014.Google Scholar
  30. 30.
    Redlich O, Kister AT. Algebraic representation of thermodynamic properties and the classification of solutions. Ind Eng Chem. 1948;40:345–8.CrossRefGoogle Scholar
  31. 31.
    Matteoli E, Lepori L, Spanedda A. Thermodynamic study of heptane + amine mixtures. Fluid Phase Equilib. 2003;212:41–52.CrossRefGoogle Scholar
  32. 32.
    Matteoli E, Gianni P, Lepori L. Thermodynamic study of heptane + secondary, tertiary and cyclic amines mixtures. Part IV. Excess and solvation enthalpies at 298.15 K. Fluid Phase Equilib. 2011;306:234–41.CrossRefGoogle Scholar
  33. 33.
    Usula M, Matteoli E, Leonelli F, Mocci F, Marincola FC, Gontrani L, et al. Thermo-physical properties of ammonium-based ionic liquid + N-methyl-2-pyrrolidone mixtures at 298.15K. Fluid Phase Equilib. 2014;383:49–54.CrossRefGoogle Scholar
  34. 34.
    Marsh KN. Excess enthalpies of benzene + cyclohexane mixtures. Int Data Ser Sel Data Mix Ser A. 1973;1:1–5.Google Scholar
  35. 35.
    Marongiu B, Porcedda S, Falconieri D, Piras A, Matteoli E, Lepori L. Excess enthalpies of mixtures of mono-carboxylic acid with dibutylether: comparison with DISQUAC predictions. J Therm Anal Calorim. 2012;108:777–82.CrossRefGoogle Scholar
  36. 36.
    Freemantle M. An introduction to ionic liquids. Cambridge: Royal Society of Chemistry; 2009. doi: 10.1039/9781849737050.
  37. 37.
    Bonhôte P, Dias A-P, Armand M, Papageorgiou N, Kalyanasundaram K, Grätzel M. Hydrophobic, highly conductive ambient-temperature molten salts. Inorg Chem. 1998;37:166.CrossRefGoogle Scholar
  38. 38.
    Wassercheid P, Keim W. Angew Chem Int Ed. 2000;39:3772–89.CrossRefGoogle Scholar
  39. 39.
    Riddick JA, Bunger WB, Sakano TK. Organic solvents. 4th ed. New York: Wiley; 1986.Google Scholar
  40. 40.
    Schmeisser M, Illner P, Puchta R, Zahl A, van Eldik R. Gutmann donor and acceptor numbers for ionic liquids. Chemistry. 2012;18:10969–82.CrossRefGoogle Scholar
  41. 41.
    Estager J, Oliferenko A, Seddon KR, Swadźba-Kwaśny M. Chlorometallate (III) ionic liquids as Lewis acidic catalysts—a quantitative study of acceptor properties. Dalton Trans. 2010;39:11375–82.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2015

Authors and Affiliations

  • Marianna Usula
    • 1
  • Natalia V. Plechkova
    • 2
  • Alessandra Piras
    • 1
  • Silvia Porcedda
    • 1
  1. 1.Dipartimento di Scienze Chimiche e GeologicheUniversità degli Studi di CagliariMonserratoItaly
  2. 2.QUILLThe Queen’s University of BelfastBelfastNorthern Ireland, UK

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