Supplementary Material
Thermophysical and Transport Properties of Blends of an Ether-derivatized Imidazolium Ionic Liquid and a Li+ Based Solvate Ionic Liquid
Yanni Wang,1 Michael C. Turk,2 Malavarayan Sankarasubramanian,1,3,§ Anirudh Srivatsa,1,† Dipankar Roy,2 and Sitaraman Krishnan,1,*
1Department of Chemical and Biomolecular Engineering, Clarkson University, Potsdam, New York 13699, United States
2Department of Physics, Clarkson University, Potsdam, New York, 13699, United States
3Materials Science and Engineering Ph.D. Program, Clarkson University, Potsdam, New York, 13699, United States
*Corresponding Author, E-mail: , Phone: +1-315-268-6661, Fax: +1-315-268-6654
§Presently at Intel Corporation, Chandler, Arizona, 85226, United States
†Presently at ITC Limited, Bengaluru 560 005, Karnataka, India
COMPARISON OF NEAT IONIC LIQUID PROPERTIES DETERMINED IN THIS WORK WITH LITERATURE VALUES
Table SI.1 Density (g cm-3) of [BuMeIm][Tf2N] at different temperaturesT ℃ / present work / literature
10 / 1.4513
25 / 1.4366 / 1.43430[1] / 1.43573[2] / 1.4377[3] / 1.43664[4] / 1.4366[5] / 1.436[6]
40 / 1.4222 / 1.41961[1] / 1.42140[2] / 1.4232[3] / 1.42234[4]
55 / 1.4079 / 1.40464[1] / 1.40723[2] / 1.4090[3] / 1.4079[5]
70 / 1.3939 / 1.38916[1] / 1.3949[3] / 1.39415[4]
85 / 1.3801
[1] Vranes M, Dozic S, Djeric V, Gadzuric S (2012) J Chem Eng Data, 57:1072–1076
[2] Troncoso J, Cerdeiriña CA, Sanmamed YA, et al. (2006) J Chem Eng Data, 51:1856–1859
[3] Krummen M, Wasserscheid P, Gmehling J (2002) J Chem Eng Data, 47:1411–1417
[4] Harris KR, Kanakubo M, Woolf LA (2007) J Chem Eng Data, 52:1080–1085
[5] Wandschneider A, Lehmann JK, Heintz A (2008) J Chem Eng Data, 53:596–599
[6] Dzyuba SV, Bartsch RA (2002) ChemPhysChem, 3:161–166
Table SI.2 Viscosity (cP) of [BuMeIm][Tf2N] at different temperatures and percentage difference from literature valuesT ℃ / present work / literature[1] / % diff. / literature[2] / % diff. / literature[3] / % diff.
10 / 98.8
25 / 48.2 / 50.05 / -3.70 / 52.3 / -7.84 / 46.8 / 2.99
40 / 27.5 / 28.28 / -2.76 / 29.0 / -5.17 / 24.8 / 10.9
55 / 17.0 / 17.90 / -5.03 / 18.4 / -7.61 / 15.2 / 11.8
70 / 11.3 / 12.09 / -6.53 / 12.4 / -8.87 / 10.5 / 7.62
85 / 7.89
[1] Vranes M, Dozic S, Djeric V, Gadzuric S (2012) J Chem Eng Data, 57:1072–1076
[2] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 14 ppm water
[3] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 410 ppm water
Table SI.3 Conductivity (mS cm-1) of [BuMeIm][Tf2N] at different temperatures and percentage difference from literature valuesT ℃ / present work / literature[1] / % diff. / literature[2] / % diff. / literature[3] / % diff.
10 / 2.54
25 / 4.86 / 4.017 / 21.0 / 3.16 / 53.8 / 3.33 / 46.0
40 / 7.95 / 6.839 / 16.3 / 5.32 / 49.4 / 5.07 / 56.8
55 / 11.7 / 10.75 / 8.84 / 8.22 / 42.3 / 8.06 / 45.2
70 / 15.9 / 15.92 / -0.13 / 11.55 / 37.7 / 11.63 / 36.7
85 / 20.5
[1] Vranes M, Dozic S, Djeric V, Gadzuric S (2012) J Chem Eng Data, 57:1072–1076
[2] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 14 ppm water
[3] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 410 ppm water
Table SI.4 Viscosity (cP) of [mEtMeIm][Tf2N] at different temperatures and percentage difference from literature valuesT ℃ / present work / literature[1] / % diff. / literature[2] / % diff.
10 / 93.6
25 / 45.0 / 48.5 / -7.22 / 48.4 / -7.02
40 / 25.6 / 26.7 / -4.12 / 26.5 / -3.40
55 / 15.1 / 16.3 / -7.36 / 16.4 / -7.93
70 / 10.1 / 10.7 / -5.61 / 10.9 / -7.34
85 / 7.18
[1] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 6 ppm water
[2] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 680 ppm water
Table SI.5 gives the ionic conductivity values of [mEtMeIm][Tf2N] determined in three replicate measurements. In the first experiment, the temperature was decreased from 85 to 10 °C, in steps of 15 °C. In the second and third experiments, the temperature was increased from 10 to 85 °C, in steps of 15 °C. The table also shows the mean conductivity values at the different temperatures of measurements, and the deviation of the measured values from the mean.
Table SI.5 Conductivity (mS cm-1) vs. temperature of [mEtMeIm][Tf2N] measured in three different experiments of this workT ℃ / Exp. 1 / Exp. 2 / Exp. 3 / Mean / deviation from mean (%)
Exp. 1 / Exp. 2 / Exp. 3
10 / 2.96 / 2.76 / 2.60 / 2.77 / -6.3% / 0.5% / 6.7%
25 / 5.52 / 5.12 / 4.90 / 5.18 / -6.1% / 1.1% / 5.7%
40 / 9.09 / 8.51 / 8.34 / 8.65 / -4.9% / 1.7% / 3.6%
55 / 13.62 / 12.83 / 13.45 / 13.30 / -2.4% / 3.7% / -1.1%
70 / 17.89 / 17.15 / 18.45 / 17.83 / -0.3% / 4.0% / -3.4%
85 / 22.51 / 22.51 / 22.59 / 22.54 / 0.1% / 0.1% / -0.2%
Table SI.6 Conductivity (mS cm-1) of [mEtMeIm][Tf2N] at different temperatures and percentage difference from literature values
T ℃ / present work / literature[1] / % diff. / literature[2] / % diff.
10 / 2.77
25 / 5.18 / 3.57 / 45.1 / 3.75 / 38.1
40 / 8.65 / 6.02 / 43.7 / 5.77 / 49.9
55 / 13.3 / 9.22 / 44.3 / 9.07 / 46.6
70 / 17.8 / 13.19 / 35.0 / 12.85 / 38.5
85 / 22.5
[1] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 6 ppm water
[2] Bulut S, Eiden P, Beichel W, et al. (2011) ChemPhysChem 12:2296–2310; 680 ppm water (note the small decrease in conductivity (for T ³ 40 °C) as the concentration of water impurity in the IL increased from 6 ppm to 680 ppm)
VOLUMETRIC PROPERTIES OF BLENDS
Table SI.7 Molar volume (cm3 mol-1) vs. temperature of mixtures with different mole fractions of [Li(G4)][Tf2N] in solutions with [mEtMeIm][Tf2N]Sample / L1 / L2 / L3 / L4 / L5 / L6 / L7 / L8
T ℃ / x1 / 0.000 / 0.081 / 0.176 / 0.290 / 0.429 / 0.667 / 1.000 / -
10 / 277.11 / 283.92 / 291.80 / 301.18 / 312.43 / 331.84 / 358.79 / 243.66
25 / 280.01 / 286.91 / 294.91 / 304.44 / 315.87 / 335.63 / 363.07 / 246.27
40 / 282.90 / 289.90 / 297.99 / 307.66 / 319.25 / 339.31 / 367.19 / 248.88
55 / 285.79 / 292.88 / 301.08 / 310.87 / 322.62 / 342.96 / 371.24 / 251.48
70 / 288.71 / 295.89 / 304.18 / 314.09 / 326.00 / 346.61 / 375.28 / 254.10
85 / 291.64 / 298.91 / 307.30 / 317.33 / 329.39 / 350.26 / 379.32 / 256.72
Table SI.8 Density (g cm-3) vs. temperature of mixtures with different mole fractions of [Li(G4)][Tf2N] in solutions with [BuMeIm][Tf2N]
T ℃ / x1 / 0.000 / 0.081 / 0.176 / 0.290 / 0.429 / 0.667 / 1.000
10 / 1.4513 / 1.4468 / 1.4418 / 1.4375 / 1.4336 / 1.4274 / 1.4197
25 / 1.4366 / 1.4319 / 1.4269 / 1.4224 / 1.4182 / 1.4114 / 1.4030
40 / 1.4222 / 1.4174 / 1.4123 / 1.4077 / 1.4033 / 1.3962 / 1.3872
55 / 1.4079 / 1.4032 / 1.3979 / 1.3932 / 1.3888 / 1.3814 / 1.3721
70 / 1.3939 / 1.3891 / 1.3837 / 1.3789 / 1.3745 / 1.3669 / 1.3573
85 / 1.3801 / 1.3752 / 1.3695 / 1.3645 / 1.3604 / 1.3527 / 1.3429
Table SI.9 Molar volume (cm3 mol-1) vs. temperature of mixtures with different mole fractions of [Li(G4)][Tf2N] in solutions with [BuMeIm][Tf2N]
T ℃ / x1 / 0.000 / 0.081 / 0.176 / 0.290 / 0.429 / 0.667 / 1.000
10 / 288.94 / 294.89 / 301.83 / 309.88 / 319.46 / 335.86 / 358.79
25 / 291.91 / 297.95 / 304.99 / 313.17 / 322.92 / 339.66 / 363.07
40 / 294.87 / 301.00 / 308.15 / 316.44 / 326.34 / 343.37 / 367.19
55 / 297.85 / 304.05 / 311.31 / 319.73 / 329.76 / 347.03 / 371.24
70 / 300.84 / 307.14 / 314.51 / 323.06 / 333.19 / 350.71 / 375.28
85 / 303.85 / 310.24 / 317.78 / 326.47 / 336.64 / 354.40 / 379.32
Figure SI.1 shows density of blends of [Li(G4)][Tf2N] and [mEtMeIm][Tf2N], calculated using the Eq. SI.1. A very good fit is observed. The adjusted r2 and root mean square error (rmse), defined by Eq. SI.2 and Eq. SI.4, respectively, were 0.9999 and 2.15×10-4 g cm-3.
ρ=509.37x1+421.34(1-x1)222.5+0.193T+x159.4+0.079T+x1x2/(1.50x1+0.49x2) / (SI.1)The adjusted r2 is defined as:
radj2=1-1-r2(n-1)n-k-1 / (SI.2)where n is the number of observation in the data used for the fit and k is the number of independent variables in the model. r2 is the coefficient of determination, defined by:
r2=1-i=1nyi-yi2i=1nyi-yi2 / (SI.3)where yi represents experimental data, yi is the mean of yi, and yi is the value predicted by the model. The root mean square error is calculated using Eq. SI.4.
rmse=i=1nyi-yi2n / (SI.4)Figure SI.1 Density of blends of [Li(G4)][Tf2N] and [mEtMeIm][Tf2N] calculated using Eq. SI.1 vs. measured density; adjusted r2=0.9998; rmse=6.3×10-4 g cm-3.
Figure SI.2 shows density of blends of [Li(G4)][Tf2N] and [BuMeIm][Tf2N], calculated using the Eq. SI.5, plotted against experimental values.
ρ=509.37x1+419.35(1-x1)232.7+0.199T+x149.2+0.074T+x1x2/(0.862x1+0.14x2) / (SI.5)Figure SI.2 Density of blends of [Li(G4)][Tf2N] and [BuMeIm][Tf2N] calculated using Eq. SI.5 vs. measured density; adjusted r2=0.9998; rmse=3.46×10-4 g cm-3.
Figure SI.3 shows the variation of the densities of blends of [Li(G4)][Tf2N] and [BuMeIm][Tf2N] with temperature and mole fraction of [Li(G4)][Tf2N].
Figure SI.3 Variation of density with (a) temperature and (b) mole fraction of [Li(G4)][Tf2N] of blends of [Li(G4)][Tf2N] and [BuMeIm][Tf2N], at ambient pressure and different temperatures in the range of 10 to 85 °C.
Figure SI.4 shows the excess molar volume vs. mole fraction of [Li(G4)][Tf2N] for blends with [mEtMeIm][Tf2N] at different temperatures. The dotted curve is based on the model
VE=x1x2b1x1+b2x2 / (SI.6)ignoring the weak temperature dependence. Figure SI.5 shows the excess volumes vs. mole fraction of [Li(G4)][Tf2N] for the blends with [BuMeIm][Tf2N] at different temperatures.
Figure SI.4 Variation of excess molar volume of mixtures of [Li(G4)][Tf2N] and [mEtMeIm][Tf2N] at ambient pressure and different temperatures in the range of 10 to 85 °C.
Figure SI.5 Variation of excess molar volume of mixtures of [Li(G4)][Tf2N] and [BuMeIm][Tf2N] at ambient pressure and different temperatures in the range of 10 to 85 °C.
If the values of VE are considered negligible compared with the total molar volume, V, of the blends:
V≅x1V1+x2V2 / (SI.7)and the relation between molar volume and the experimentally measured density, r, is:
V=x1M1+x2M2ρ / (SI.8)where M1 and M2 are the molecular weights, and x1 and x2 are the mole fractions of species 1 and 2, respectively. From Eqs. SI.7 and SI.8:
r=x1M1+x2M2x1V1+x2V2 / (SI.9)Using the fact that M1=r1V1 and M2=r2V2, the relation between the mixture density, r, and the pure component values, r1 and r2, is:
r=x1V1x1V1+x2V2r1+x2V2x1V1+x2V2r2=F1r1+F2r2 / (SI.10)where F1 and F2 are the volume fractions of [Li(G4)][Tf2N] and [mEtMeIm][Tf2N] in the mixture, respectively. Because the data in Fig. 2a in the article show that r, r1, and r2 are linearly dependent on temperature, one would expect the volume fractions F1 and F2 to be independent of temperature, and depend only on the composition of the solution. This was indeed found to be the case. Figure SI.6a shows the volume fractions of [Li(G4)][Tf2N] in solutions of different compositions in the temperature range of 10 to 85 °C. There was little variation of F1 with temperature. Figure SI.6b shows the variation of F1 with composition, x1. Figure SI.7 shows a similar set of plots for the [BuMeIm][Tf2N] blends.
Figure SI.6 The volume fraction of [Li(G4)][Tf2N] in blends with [mEtMeIm][Tf2N] versus (a) temperature and (b) mole fraction of [Li(G4)][Tf2N].
Figure SI.7 The volume fraction of [Li(G4)][Tf2N] in blends with [BuMeIm][Tf2N] versus (a) temperature and (b) mole fraction of [Li(G4)][Tf2N].
Alternative form of density correlation
The density variations could also be fitted well to an equation that was linear in T and quadratic in x1. Eq. SI.11 gives the density of the blends of [Li(G4)][Tf2N] and [mEtMeIm][Tf2N] as a function of temperature, T (K), and mole fraction, x1. The coefficients are reported along with the standard uncertainties. The adjusted r2 value for the fit was 0.9998 and root mean square error was 6.3×10-4 g cm-3. Figure SI.8 shows a comparison of the calculated and measured density values. A good agreement is seen.
ρT,x1=-1.010±0.008×10-3T+0.031±0.002x12-0.132±0.002x1+1.805±0.002 / (SI.11)
A similar analysis of the density of the blends of [Li(G4)][Tf2N] with the [BuMeIm][Tf2N] IL resulted in Eq. SI.12 for the correlation of density of the blend with temperature, T, and mole fraction, x1, of [Li(G4)][Tf2N] in the solution. Figure SI.9 shows a comparison of the calculated and measured density values for these blends. The adjusted r2 value was 0.9936 and root mean square error was 2.2´10-3 g cm-3.