Ramzi Zarrouguia*, Mahmoud Dhahbia and Daniel Lemordantb

Electronic supplementary material

Volumetric and Transport Properties of N-Butyl-N-methylpyrrolidinium bis(Trifluoromethanesulfonyl)imide-Methanol Binary Mixtures

Ramzi Zarrouguia*, Mahmoud Dhahbia and Daniel Lemordantb

a Laboratoire Eau et Technologies Membranaires /CERTE, BP.273, 8020 Soliman, Tunisia.

b Laboratoire Physicochimie des Matériaux et des Biomolécules (PCMB, EA4244), Equipe CIME, Université F.

Rabelais, Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours, France.

*corresponding author:

Abstract

Densities, viscosities and ionic conductivities were measured for the binary mixtures containing the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and methanol over the entire range of compositions at the temperature varying from 253.15 K to 318.15 K. The viscosities and densities decrease monotonously with temperature and the content of ionic liquids (ILs). Furthermore, excess isobaric expansion coefficient has been calculated from the experimental densities. The dependence of temperature on the viscosity has been fitted to the Arrhenius law with high precision. The dependence of temperature on the ionic conductivity has also been gauged by both of the Arrhenius and Vogel–Tamman–Fulcher (VTF) equations. In fact, the shape of the curves shows that the temperature dependence of the conductivity does not follow a simple Arrhenius law but a better fitting of experimental results is achieved using the VTF model. Additionally, the effects of ILs concentration on the viscosity and the conductivity have been examined using the Walden rule which shows that the variation of conductivity is inversely proportional to viscosity. Excess molar volumes and viscosity deviations for all mixtures are evaluated and well fitted to the Redlich–Kister polynomial expansions. Physico-chemical properties show two clearly distinguished behaviours corresponding to ILs-rich and methanol-rich regions, with distinct transport and volumetric properties. The obtained results are discussed in terms of dipolar interactions and hydrogen bonding establishment between ions of ILs and the methanol molecules.

Keywords

Ionic liquid; Methanol; Viscosity; Conductivity; Walden product; Excess properties.

Table 1S The correlated parameters and the relative deviations for the densities with Eq. (1)

x1 / α / g.cm-3 / -104b / g.cm-3.K-1 / r2 / 104.s
0 / 1.0612 / 9.15 / 1 / 3.66
0.05 / 1.2679 / 9.77 / 1 / 4.18
0.11 / 1.3921 / 9.86 / 1 / 4.25
0.16 / 1.4698 / 9.79 / 1 / 4.19
0.21 / 1.5173 / 9.67 / 1 / 4.09
0.26 / 1.5467 / 9.57 / 1 / 4.00
0.32 / 1.5662 / 9.52 / 1 / 3.96
0.37 / 1.5810 / 9.53 / 1 / 3.97
0.42 / 1.5941 / 9.57 / 1 / 4.01
0.47 / 1.6064 / 9.64 / 1 / 4.06
0.53 / 1.6174 / 9.67 / 1 / 4.09
0.58 / 1.6258 / 9.65 / 1 / 4.07
0.63 / 1.6304 / 9.54 / 1 / 3.98
0.68 / 1.6297 / 9.33 / 1 / 3.80
0.74 / 1.6237 / 9.01 / 1 / 3.55
0.79 / 1.6135 / 8.64 / 1 / 3.26
0.84 / 1.6024 / 8.27 / 1 / 2.99
0.89 / 1.5962 / 8.02 / 0.9998 / 2.81
0.95 / 1.6038 / 8.05 / 0.9992 / 2.83
1 / 1.6376 / 8.56 / 0.9978 / 3.21

Table 2S Experimental viscosity, η, for all fractions x1 of the binary mixtures PYR14-MeOH.

η / mPa.s
x1 / C1 / mol.L-1 / T = 293.15 K / T = 298.15 K / T = 303.15 K / T = 308.15 K / T = 313.15 K / T = 318.15 K
0 / 0 / 0.74 / 0.70 / 0.66 / 0.61 / 0.57 / 0.53
0.05 / 0.97 / 1.02 / 0.94 / 0.88 / 0.82 / 0.77 / 0.73
0.11 / 1.55 / 2.16 / 1.93 / 1.75 / 1.60 / 1.47 / 1.36
0.16 / 1.94 / 3.90 / 3.43 / 3.06 / 2.75 / 2.48 / 2.26
0.21 / 2.22 / 6.01 / 5.24 / 4.62 / 4.10 / 3.67 / 3.30
0.26 / 2.42 / 8.31 / 7.20 / 6.29 / 5.53 / 4.92 / 4.39
0.32 / 2.58 / 10.65 / 9.18 / 7.96 / 6.97 / 6.15 / 5.45
0.37 / 2.71 / 12.95 / 11.10 / 9.57 / 8.34 / 7.34 / 6.46
0.42 / 2.82 / 15.15 / 12.93 / 11.11 / 9.64 / 8.45 / 7.41
0.47 / 2.90 / 17.28 / 14.69 / 12.57 / 10.87 / 9.51 / 8.32
0.53 / 2.98 / 19.42 / 16.43 / 14.02 / 12.09 / 10.55 / 9.22
0.58 / 3.04 / 21.71 / 18.28 / 15.54 / 13.36 / 11.64 / 10.16
0.63 / 3.10 / 24.35 / 20.39 / 17.28 / 14.80 / 12.85 / 11.22
0.68 / 3.14 / 27.62 / 22.99 / 19.39 / 16.54 / 14.30 / 12.47
0.74 / 3.19 / 31.88 / 26.35 / 22.08 / 18.74 / 16.10 / 14.02
0.79 / 3.22 / 37.56 / 30.79 / 25.59 / 21.60 / 18.40 / 15.95
0.84 / 3.26 / 45.18 / 36.72 / 30.20 / 25.34 / 21.34 / 18.39
0.89 / 3.29 / 55.32 / 44.57 / 36.24 / 30.20 / 25.09 / 21.42
0.95 / 3.31 / 68.67 / 54.85 / 44.05 / 36.44 / 29.83 / 25.16
1.00 / 3.34 / 86.03 / 68.14 / 54.03 / 44.37 / 35.75 / 29.71

Table 3S The correlated resultants by Eq.3

x1 / C1 / mol.L-1 / 106.η µ / mPa.s / Ea,η / kJ.mol-1
0 / 0 / 3.978 / 10.55
0.05 / 0.97 / 6.411 / 10.11
0.11 / 1.55 / 2.580 / 14.15
0.16 / 1.94 / 1.558 / 16.82
0.21 / 2.22 / 1.183 / 18.55
0.26 / 2.42 / 0.985 / 19.79
0.32 / 2.58 / 0.856 / 20.74
0.37 / 2.71 / 0.764 / 21.49
0.42 / 2.82 / 0.696 / 22.10
0.47 / 2.90 / 0.645 / 22.60
0.53 / 2.98 / 0.604 / 23.04
0.58 / 3.04 / 0.564 / 23.48
0.63 / 3.10 / 0.514 / 23.98
0.68 / 3.14 / 0.448 / 24.62
0.74 / 3.19 / 0.364 / 25.47
0.79 / 3.22 / 0.274 / 26.56
0.84 / 3.26 / 0.190 / 27.90
0.89 / 3.29 / 0.123 / 29.45
0.95 / 3.31 / 0.076 / 31.16
1.00 / 3.34 / 0.045 / 32.98

Table 4S Experimental conductivity,k, for all fractions x1 of the mixtures PYR14-MeOH.

k / mS.cm-1
x1 / C1 / mol.L-1 / T = 293.15 K / T = 298.15 K / T = 303.15 K / T = 308.15 K / T = 313.15 K / T = 318.15 K
0 / 0 / 0 / 0 / 0 / 0 / 0 / 0
0.05 / 0.97 / 3.68 / 3.99 / 4.3 / 4.64 / 5.04 / 5.38
0.11 / 1.55 / 6.28 / 6.84 / 7.54 / 8.16 / 8.65 / 9.42
0.16 / 1.94 / 12.2 / 13.25 / 14.26 / 15.41 / 16.6 / 17.97
0.21 / 2.22 / 16 / 17.29 / 18.8 / 20.7 / 22.4 / 24
0.26 / 2.42 / 17.72 / 19.3 / 21.7 / 23.75 / 25.3 / 27
0.32 / 2.58 / 19.79 / 21.46 / 23.54 / 25.51 / 27.92 / 30.15
0.37 / 2.71 / 21.1 / 23.2 / 25.3 / 27.41 / 29.51 / 31.77
0.42 / 2.82 / 21.4 / 23.7 / 26.1 / 28.6 / 30.72 / 32.6
0.47 / 2.90 / 20.38 / 23.28 / 25.91 / 28.54 / 30.9 / 33.01
0.53 / 2.98 / 18.2 / 21.22 / 23.71 / 26.5 / 29.12 / 31.8
0.58 / 3.04 / 16.33 / 18.75 / 21.03 / 23.59 / 26.3 / 28.58
0.63 / 3.10 / 14.68 / 16.61 / 18.44 / 20.95 / 23.81 / 25.52
0.68 / 3.14 / 12.26 / 14.26 / 15.97 / 18.39 / 20.81 / 22.66
0.74 / 3.19 / 9.98 / 11.99 / 13.54 / 15.68 / 17.96 / 19.83
0.79 / 3.22 / 8.2 / 9.91 / 11.33 / 13.33 / 15.46 / 17.03
0.84 / 3.26 / 6.49 / 7.86 / 9.4 / 11.04 / 12.95 / 14.3
0.89 / 3.29 / 4.02 / 4.95 / 6,01 / 6.86 / 8.76 / 9.91
1.00 / 3.34 / 2.29 / 2.82 / 3.44 / 4.15 / 4.88 / 5.59