A semi-empirical equation for determining the surface tension of imidazolium-based ionic liquids
Subject Areas : Kinetics and Thermodynamics
1 - Department of Chemistry, Marvdasht Branch, Islamic Azad University, Marvdasht, 7371113119, Iran
Keywords: Ionic liquids, Potential model, Internal pressure, Surface tension. ,
Abstract :
In this research, using appropriate thermodynamic arguments and models, a semi-empirical equation was obtained to calculate the surface tension of imidazolium-based ionic liquids. In the first method used, the Stockmayer potential model was chosen to describe the interaction between particles, and an isothermal thermodynamic equation was extracted from this equation. Using the experimental data of pVT, the parameters of the thermodynamic equation and potential function were obtained. These parameters were used to estimate the internal pressure and pair correlation function of the studied systems. Then, using the internal pressure and applying some thermodynamic arguments and approximations, the surface tension was calculated from the Kirkwood and Buff equation. Experimental pVT data of ionic liquids, in a wide temperature range, were extracted from available sources. The values of surface tension calculated by this method are in good agreement with the reported values, and the trend of their changes with temperature is also consistent with the trend of experimental data.
[1] Marsh K.N, Boxall J.A, Lichtenthaler R, Room temperature ionic liquids and their mixtures-a review, Fluid Phase Equilib, 219: (1) :93–98 (2004).
[2] Tariq M., Freire M.G., Saramago B., Coutinho JA., Lopes JN., Rebelo LP., Surface tension of ionic liquids and ionic liquid solutions, Chem. Soc. Rev., 41: 829–868 (2012).
[3] Freire M.G., Carvalho P.J., Fernandes A.M., Marrucho I.M., Queimada A.J., Coutinho J.A.P., Surface tensions of imidazolium based ionic liquids: Anion, cation, temperature and water effect, Journal of Colloid and Interface Science, 314: 621–630 (2007).
[4] Sanchez L. G., Espel J. R., Onink F., Meindersma G. W., Haan A. B., Density, viscosity, and surface tension of synthesis grade imidazolium,pyridinium, and pyrrolidinium based room temperature ionic liquids, J. Chem. Eng. Data 54: 2803–2812 (2009).
[5] Greer A.J. Jacquemin J., Hardacre C., Industrial applications of ionic liquids, Molecules, 25: 5207-5238 (2020).
[6] Santos C.S., Baldelli S., Gas–liquid interface of room-temperature ionic liquids, Chem. Soc. Rev., 39: 2136–2145 (2010).
[7] Lockett V., Sedev R., Harmer S., Ralston J., Horne M., Rodopoulos T., Orientation and mutual location of ions at the surface of ionic liquids, Phys. Chem. Chem. Phys., 12: 13816–13827 (2010).
[8] Stockmayer W.H., Second virial coefficients of polar gases, J. Chem. Phys., 9(5): 398–402 (1941).
[9] Kirkwood J.G., Buff F.P., The statistical mechanical theory of solutions. I, J. Chem. Phys., 19: 774–777 (1951).
[10] Ravi S., Kalidoss M., Amoros J., A new empirical structure factor for real liquids using internal pressure, Fluid Phase Equilib., 178: 33-44 (2001).
[11] Bahadori M., Akbari Z., Prediction of the surface tension of cesium in the whole liquid range, Phys. and Chem. of Liq., 54: 454-461 (2015).
[12] Machida H., Sato Y., Smith R. L., Pressure volume temperature (PVT) measurements of ionic liquids ([bmim+][PF6-], [bmim+][BF4-], [bmim+][OcSO4-]) and analysis with the Sanchez Lacombe equation of state, Fluid Phase Equilib., 264(1): 147-155 (2008).
[13] Taguchi R., Machida H., Sato Y., Smith R.L., High-pressure densities of 1-alkyl-3-methylimidazolium hexafluorophosphates and 1-alkyl-3-methylimidazolium tetrafluoroborates at temperatures from (313 to 473) K and at pressures up to 200 MPa, J. Chem. Eng. Data, 54: 22-27 (2009).
[14] Sanmamed Y.A., Gonzalez-Salgado D., Troncoso J., Romani L., Baylaucq A., Boned C., Experimental methodology for precise determination of density of RTILs as a function of temperature and pressure using vibrating tube densimeters, J. Chem. Thermodyn., 42(4): 553-563 (2010).
[15] De Azevedo R.G., Esperança J.M.S.S., Szydlowski J.,. Visak Z.P, Pires P.F., Guedes H.J.R., Rebelo L.P.N., Thermophysical and thermodynamic properties of ionic liquids over an extended pressure range: [bmim][NTf2] and [hmim][NTf2], J. Chem. Thermodyn., 37: 888-899 (2005).
[16] Gardas R. L., Freire M. G., Carvalho P. J., Marrucho I. M., Fonseca I. M. A., Ferreira A. G. M., Coutinho J. A. P., P-rho-T measurements of imidazolium-based ionic liquids, J. Chem. Eng. Data, 52: 1881-1888 (2007).
[17] Potoff J.J., Panagiotopoulos A. Z., Critical point and phase behaviour of the pure fluids and a Lennard-Jones mixture, J. Chem Phys., 109: 10914–10920 (1998).
[18] Valderrama J.O., Robles P.A.. Critical properties, normal boiling temperatures, and acentric factors of fifty ionic liquids, Ind. Eng. Chem. Res., 46: 1338-1344 (2007). [19] Kolbeck C., Lehmann J., Lovelock K.R.J., Cremer T., Paape N., Wasserscheid P., Froba A.P., Maier F., Steinruck H.P., Density and Surface tension of ionic liquids, J. Phys. Chem. B, 114: 17025–17036 (2010).
[20] Carvalho P. J., Freire M. G., Marrucho I. M., Queimada A. J., Coutinho J. A. P., Surface tensions for the 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, J. Chem. Eng. Data, , 53: 1346–1350 (2008).
[21] Ghatee M.H., Zolghadr A.R., Surface tension measurements of imidazolium-based ionic liquids at liquid–vapor equilibrium, Fluid Phase Equilib, 263: 168–175 (2008).
[22] Huddleston J.G., Visser A.E., Reichert W.M., Willauer H.D., Broker G. A., Rogers R.D., Characterization and comparison of hydrophilic and hydrophobic room temperature ionic liquids incorporating the imidazolium cation, Green Chem., 3: 156–164 ( 2001).
[23] Shamsipur M., Akbari A., Beigi M., Teymouri M., Pourmortazavi S.M., Irandoust M., Physical and electrochemical properties of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, J. Mol. Liq., 157: 43–50 (2010).
[24] Rebelo L.P.N., Lopes J.N.C., Esperanc J.M.S.S., Filipe E., On the Critical Temperature, Normal Boiling Point, and Vapor Pressure of Ionic Liquids, J. Phys. Chem. B, 109: 6040–6043 (2005).
[25] Muhammad A., Mutalib M.I.A., Wilfred C.D., Murugesan T., Shafeeq A., Thermophysical properties of 1-hexyl-3-methyl imidazolium based ionic liquids with tetrafluoroborate, hexafluorophosphate and bis(trifluoromethylsulfonyl)imide anions, J. Chem. Thermodyn., 40: 1433–1438 (2008).
[26] Klomfar J., Souckova M., Patek J., Surface tension measurements with validated accuracy for four 1-alkyl-3-methylimidazolium based ionic liquids, J. Chem. Thermodyn., 42: 323–330 (2010).
[27] Tariq M., Serro A. P., Mata J.L., Saramago B., Esperanc J.M.S.S., Lopes J.N.C., Rebelo L.P.N., High-temperature surface tension and density measurements of 1-alkyl-3-methylimidazolium bistriflamide ionic liquids, Fluid Phase Equilib., 294: 131–138 (2010).
