Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with ethanol at T = (293.15–313.15) K

Article abstract of DOI:10.1007/s10973-018-7399-0

In this study, density, speed of sound and viscosity of binary mixtures of ionic liquids + ethanol have been measured as a function of composition at T = (293.15–313.15) K and atmospheric pressure. The ionic liquids studied were: {n-butylammonium acetate (N4Ace), n-butylammonium propanoate (N4Pro), n-butylammonium hexanoate (N4Hex), and n-butylammonium decanoate (N4Dec)}. Excess molar volume, (Formula presented.), deviation in isentropic compressibility, (Formula presented.), deviation in viscosity, (Formula presented.), and excess Gibbs energy of activation of viscous flow, (Formula presented.), were obtained from experimental results and correlated with the Redlich–Kister polynomial equation. Ionic liquids were synthesized and characterized using ¹H-NMR, ¹³C-NMR and FTIR spectroscopy techniques. For all systems studied, the values of (Formula presented.), (Formula presented.) and (Formula presented.) were negative over the entire composition range, whereas (Formula presented.) values were positive over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.

Full text of DOI:10.1007/s10973-018-7399-0

Journal of Thermal Analysis and Calorimetry
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Thermodynamic properties of binary mixtures of n-butylammonium-
based ionic liquids with ethanol at T = (293.15–313.15) K
Samara Storion Bittencourt1 • Heloisa Emi Hoga2 • Ricardo Belchior Torres2
1
•
Jos e´ Vicente Hallak d’Angelo
Received: 15 January 2018 / Accepted: 21 May 2018
Ó Akad e´ miai Kiad o´ , Budapest, Hungary 2018
Abstract
In this study, density, speed of sound and viscosity of binary mixtures of ionic liquids ? ethanol have been measured as a
function of composition at T = (293.15–313.15) K and atmospheric pressure. The ionic liquids studied were: {n-buty-
lammonium acetate (N4Ace), n-butylammonium propanoate (N4Pro), n-butylammonium hexanoate (N4Hex), and n-
E
m
butylammonium decanoate (N4Dec)}. Excess molar volume, V , deviation in isentropic compressibility, DjS, deviation in
ÃE
viscosity, Dg, and excess Gibbs energy of activation of viscous flow, DG , were obtained from experimental results and
correlated with the Redlich–Kister polynomial equation. Ionic liquids were synthesized and characterized using H-NMR,
1
1
3
E
m
C-NMR and FTIR spectroscopy techniques. For all systems studied, the values of V , DjS and Dg were negative over the
entire composition range, whereas DG values were positive over the entire composition range. The results obtained were
discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.
ÃE
Keywords Thermodynamic properties Á Spectroscopy Á Ionic liquids Á Ethanol
Introduction
physical and chemical properties, they have been widely
used as solvents for chemical synthesis, homogeneous
catalysis, biocatalysis, nanomaterial preparations, tem-
plates for production of porous solids, hydraulic, propel-
lants, thermal, magnetic and optical fluids, composite of
materials and in various devices and processes [3, 4].
The ionic liquids are a result of the combination of
organic cations and various anions. These compounds are
divided into two groups: aprotic, also considered as
‘‘classic’’, and protic, generally prepared by neutralization
reaction of an organic Br o¨ nsted base and a Br o¨ nsted acid.
These combinations lead to the production of liquids with
different features and applications [5, 6].
Ionic liquids (ILs) are salt melts comprised solely of ions
and exhibit very low melting points compared to classical
molten salts. The term ‘‘IL’’ is commonly used when the
melting point is equal to, lower than 100 °C, while ‘‘RTIL’’
specifically refers to ILs with melting points lower than, or
equal to room temperature (RT) [1]. These compounds
present many attractive properties like extremely low
vaporization pressure and melting point, excellent thermal
stability and wide liquid ranges [2]. Due to their special
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10973-018-7399-0) contains
supplementary material, which is available to authorized
users.
The density and viscosity properties of the binary mix-
tures containing aprotic ILs (AILs) have been widely
investigated. In general, these binary mixtures contain
imidazole, pyridinium, phosphonium, and pyrrolidinium
based. However, studies about experimental results of
volumetric, viscometric and acoustic viscosity properties of
binary mixtures containing protic ionic liquids (PILs) are
relatively limited [5, 6].
&
Ricardo Belchior Torres
belchior@fei.edu.br
1
Department of Chemical Systems Engineering, Chemical
Engineering School, University of Campinas, UNICAMP,
500, Albert Einstein Avenue, Campinas, SP 13083-852,
Brazil
Thermodynamics properties of binary and multicom-
ponent liquid mixtures are required in many chemical
engineering calculations involving fluid flow, heat and
mass transfer. These properties can provide valuable
2
Departamento de Engenharia Qu ´ı mica, Centro Universit a´ rio
FEI, Avenida Humberto Alencar Castelo Branco, 3972,
S a˜ o Bernardo do Campo, SP 09850-901, Brazil
123

S. S. Bittencourt et al.
information about molecular interactions and structural
effects.
compressibility, DjS, deviation in viscosity, Dg, and excess
Gibbs energy of activation of viscous flow, DG . The
ÃE
The ammonium ILs obtained by the method of acid–
base neutralization using amine and acids have attracted
researcher’s attention because of their excellent catalytic
effects and other advantages such as easy preparation, low
cost and low toxicity [5, 6]. To improve the application of
ionic liquids, it is necessary to study thermodynamics
properties of systems containing ILs with other
compounds.
results were analyzed in term of structural effects and
intermolecular interactions between like and unlike
molecules.
Experimental
Chemicals
Thermodynamics properties of binary mixtures of ionic
liquids with ethanol have been studied by G o´ mez et al. [5],
Xu et al. [6], Kurnia et al. [7], Xu et al. [8], Rilo et al. [9],
Pereiro and Rodr ´ı guez [10], Gonz a´ lez et al. [11], Qian et al.
Acetic acid (Merck, mass fraction purity C 0.993), pro-
panoic acid (Sigma-Aldrich, mass fraction purity C 0.995),
hexanoic acid (Merck, mass fraction purity C 0.98),
decanoic acid (Merck, mass fraction purity C 0.98), n-
butylamine (Merck, mass fraction purity C 0.99), ethanol
(Merck, mass fraction purity C 0.999) were used without
further purification. The details of the pure components
used are listed in Table 1. The density, speed of sound and
viscosity of pure components are presented in Table 2
along with the corresponding literature values. Deviations
between our results and those found in the literature are
possibly due to the water content, different sources of
materials, amount and sort of impurity and different tech-
niques of measurement.
[
12], Requejo et al. [13], Garc ´ı a-Miaja et al. [14],
Wang et al. [15], Zhang et al. [16], Garc ´ı a-Mardones et al.
17], Vasanthakumar et al. [18], Lu et al. [19] and
[
Zhou et al. [20].
As a continuation of thermodynamics and spectroscopic
studies containing ionic liquids [21, 22], in present study,
n-butylammonium acetate (N4Ace), n-butylammonium
propanoate (N4Pro), n-butylammonium hexanoate
(
N4Hex) and n-butylammonium decanoate (N4Dec) were
1
13
synthesized and characterized by using H-NMR, C-
NMR and FTIR spectroscopy techniques. Furthermore,
experimental data of density, speed of sound and viscosity
for binary mixtures of {(N4Ace), or (N4Pro), or (N4Hex),
or (N4Dec) ? ethanol) have been measured as a function
of composition and at T = (293.15–313.15) K and atmo-
spheric pressure. These results were used to calculate the
Synthesis and characterization of ILs
The ionic liquids (N4Ace, N4Pro, N4Hex and N4Dec)
were synthesized by the method of acid–base neutralization
using n-butylamine and (acetic, propanoic, hexanoic and
E
m
excess molar volume, V , deviation in isentropic
Table 1 Purities and suppliers of the chemical substances used in this study
Compounds
CAS
number
Supplier
Purity (mass
fraction)
Purification
method
Analysis
method
Water
content/mass%
a
a
n-Butylamine
109-73-9
64-19-7
79-09-4
142-62-1
334-48-5
64-17-5
Merck
C 0.990
None
\ 0.2
a
a
Acetic acid
Merck
C 0.999
None
\ 0.07
a
a
Propanoic acid
Sigma-Aldrich
Merck
C 0.995
None
\ 0.15
a
Hexanoic acid
C 0.980
None
–
–
a
Decanoic acid
Merck
C 0.980
None
a
a
Ethanol
Merck
C 0.999
None
\ 0.1
1
b
n-Butylammonium acetate
n-Butylammonium propanoate
n-Butylammonium hexanoate
n-Butylammonium decanoate
Synthesized
Synthesized
Synthesized
Synthesized
C 0.993
C 0.993
C 0.996
C 0.968
Dried in vacuo
Dried in vacuo
Dried in vacuo
Dried in vacuo
H-NMR
\ 0.5882
1
b
H-NMR
\ 0.1775
1
b
H-NMR
\ 0.3362
1
b
H-NMR
\ 0.5433
a
Stated by supplier
b
Analyzed by Karl Fischer titration
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 2 Comparison of measured values of density, speed of sound and viscosity of the pure substances with those in the literature at different
temperatures
-
3
-1
u/m s
Component
T/K
q/g cm
g/mPa s
Experimental Literature
Experimental Literature
Experimental Literature
n-Butylammonium acetate 293.15 0.962920
0.95961 [8] 1488.05
1102.6
765.41
544.89
397.03
295.14
961.33
698.41
517.21
389.41
297.91
1111.1
817.03
609.04
459.69
350.99
1051.6
760.69
559.43
416.99
314.26
771.694 [8]
546.348 [8]
397.170 [8]
294.586 [8]
222.241 [8]
2
3
3
3
98.15 0.959722
03.15 0.956492
08.15 0.953321
13.15 0.950169
0.95644 [8] 1468.26
0.95333 [8] 1450.05
0.95015 [8] 1432.96
0.94698 [8] 1416.70
1444.80
n-Butylammonium
propanoate
293.15 0.946152
2
3
3
3
98.15 0.942871
03.15 0.939583
08.15 0.936328
13.15 0.933086
1425.23
1406.79
1389.25
1372.49
n-Butylammonium
hexanoate
293.15 0.912253
1415.23
2
3
3
3
98.15 0.909000
03.15 0.905710
08.15 0.902430
13.15 0.899161
1396.01
1377.42
1359.40
1341.95
n-Butylammonium
decanoate
293.15 0.893902
1432.39
2
3
3
3
98.15 0.890675
03.15 0.887410
08.15 0.884168
13.15 0.880932
1413.87
1395.82
1378.18
1361.03
Ethanol
293.15 0.789645
0.78954 [8] 1160.99
0.78525 [8] 1143.84
1160 [10]
1.2072
1.218 [6]
2
98.15 0.785356
1143 [23]; 1142.97
[
1.1008
1.134 [6]; 1.0961
[7]
24]
303.15 0.781036
308.15 0.776684
313.15 0.772300
0.78093 [8] 1126.82
0.77657 [8] 1109.92
0.77218 [8] 1093.16
1127 [10]
1.0048
1.015 [6]
0.910 [6]
0.836 [6]
1109.19 [24]
1093 [25]
0.91867
0.84223
-
4
-3
Standard uncertainties u are: u(T) = 0.02 K; u(p) = 1 kPa, and the combined expanded uncertainties were U
c
is U
(u) = 2.01 m s ; Ucr(g) = 0.09 with 0.95 level of confidence (k = 2). All the experiments were carried out at 93.2 kPa pressure with
u(p) = 1 kPa
c
(q) = 3 9 10 g cm ;
-1
U
c
1
13
decanoic) acids and characterized by H-NMR, C-NMR
and FTIR spectroscopy techniques [26, 27]. The ionic
liquids were used after drying under vacuum with stirring
for at least 48 h at T = 318.15 K. Figure 1 shows molec-
(& 3362 ppm) N4Hex and (& 5433 ppm) N4Dec. The
amount of water present in the ILs has been taken into
account to estimate the uncertainties in mole fraction,
density, speed of sound and viscosity. The total peaks
1
1
ular structure of the synthesized ILs. The analysis of H-
integrals in H-NMR spectrums for ILs were found to
1
3
NMR and C-NMR were obtained in an Avance III 600
HD Bruker spectrometer operating at 600 MHz for protons
and 150 MHz for carbon. The solvent used was deuterated
correspond to a mass fraction purity in the range of
0.968–0.996 (Table 1).
1
13
On analyzing the H-NMR and C-NMR spectra of the
synthesized ILs (Figs. S1–S18), it was observed that the
chemical displacements of the amino group of n-buty-
lamine were altered after the formation of n-butylammo-
nium ion. This shift can be attributed to the protonation of
the amino group and the altered multiplicity of the amine
hydrogen signal. Integration of hydrogens into the amine
and IL was confirmed by the presence of two and three
hydrogen signals in the spectra, respectively (Sect. 2.3). On
chloroform (CDCl ) containing tetramethylsilane (TMS).
3
The IR spectra were obtained in Fourier transform infrared
spectroscopy Nicolet with attenuated total reflectance
(
FTIR-ATR) (Model 6700) using 32 scans per spectrum
-1
-
resolution of 4 cm in the wavenumber 4000–450 cm
1
.
The water content for the synthesized ILs, analyzed by
Karl Fischer titration (Metrohm 915 KF Ti-Touch), was
found to be (& 5882 ppm) N4Ace, (& 1775 ppm) N4Pro,
123

S. S. Bittencourt et al.
Fig. 1 Molecular structure of n-
butylamine, acids and ionic
liquids obtained by acid–base
neutralization
3
1
H C
4
NH2
3
2
n–butylamine
O
1
5
3
O
+
H C
6
NH3
2
3
–
H C
OH
4
O
CH3
3
1
2
n–butylammonium acetate
Acetic acid
O
6
4
O
1
3
3
CH3
+
H C
H C
7
NH3
3
3
–
OH
5
O
1
2
2
n–butylammonium propanoate
Propanoic acid
O
1
9
7
O
5
3
+
3
5
H C
NH3
3
–
8
O
1
CH3
1
0
H C
OH
3
2
4
6
4
2
6
n–butylammonium hexanoate
Hexanoic acid
O
9
7
5
3
H C
1
OH
3
8
6
4
2
1
0
Decanoic acid
1
3
11
O
+
3
5
7
9
H C
NH3
3
–
1
2
1
4
O
1
CH3
2
4
6
8
1
0
n–butylammonium decanoate
comparing the signal of n-butylamine ion, it was observed
right. Primary and secondary ammonia salts absorb in the
-
1
middle of the range of 3100–2700 cm . A broadband, in
that the chemical displacement of the amino group was
-
general, appears near 2100 cm [28, 29].
1
1
6
.42 ppm in n-butylamine and in the range of
.35–7.52 ppm in ILs [6, 8, 27–29]. The integrated signal
1
of the amino group in the H-NMR spectrum also changed,
indicating the presence of three hydrogens in ILs. It is also
important to highlight the presence of the signals on the
carbonyl group in the range of 178.55–182.22 ppm, rep-
resenting an offset due to the formation of the anions
Chemical shifts
n-Butylamine
1
n-Butylamine: H-NMR (CDCl , 600 MHz, ppm): d 2.69
3
[
6, 8, 27–29].
(2H, t, H-1), 1.43 (2H, m, H-2), 1.35 (2H, m, H-3), 0.92
1
(3H, t, H-4), 1.42 (2H, s, NH2); C-NMR (CDCl3,
3
Analysis of the infrared spectroscopy allows knowing if
the ILs formed suffered degradation in the process of
synthesis, as it is possible to know what functional groups
are present in ILs. Figures S19–S22 show the bands in the
150 MHz, ppm): d 41.98 (CH , C-1), 35.98 (CH , C-2),
2
2
20.09 (CH , C-3), 13.97 (CH , C-5).
2
3
-
1
range of 1560 and 1390 cm that represent the CO bond
n-Butylammonium acetate (N4Ace)
confirming the presence of the carbonyl group. In the range
-
1
of 3300 and 2600 cm , is characteristic of the N–H stretch
broad). The ammonium ion absorbs to the left in this
range, while the tertiary ammonium salt absorbs to the
Reagents: n-Butylamine and acetic acid. Reaction tem-
1
(
perature 20 °C and reaction time 24 h. H-NMR (CDCl ,
3
600 MHz, ppm): d 2.82 (3H, t, H-2), 1.93 (2H, s, H-3),
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 3 Experimental densities, speed of sound, excess molar vol-
umes and deviations in isentropic compressibility for the binary
mixtures (ionic liquids ? ethanol) at different temperatures
Table 3 (continued)
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
x1
q/g cm
DjS /TPa
-
3
-1
E
m
3
V /cm mol
-1
-1
x1
q/g cm
u/m s
DjS /TPa
0.3001
0.877855
0.887521
0.896168
0.903597
0.910676
0.917244
0.923046
0.928497
0.933416
0.937856
0.942119
0.946073
0.949893
0.953173
1282.92
1300.57
1317.11
1331.24
1345.19
1358.28
1370.18
1381.73
1392.42
1402.41
1412.17
1421.91
1431.50
1440.47
- 0.816
- 0.819
- 0.806
- 0.765
- 0.721
- 0.665
- 0.604
- 0.539
- 0.471
- 0.400
- 0.335
- 0.247
- 0.161
- 0.081
- 163.53
- 163.97
- 161.34
- 155.30
- 147.11
- 136.60
- 124.92
- 111.81
- 97.87
- 83.38
- 68.02
- 51.48
- 33.91
- 17.60
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
0.7495
0.7988
0.8496
0.9015
0.9493
x
1
n-butylammonium acetate ? (1 - x
1
) ethanol
T = 293.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
0.7495
0.7988
0.8496
0.9015
0.9493
0.813263
0.832102
0.848466
0.862423
0.874707
0.885200
0.894717
0.903249
0.910587
0.917584
0.924078
0.929818
0.935210
0.940062
0.944437
0.948632
0.952534
0.956331
0.959627
1196.21
1225.11
1251.48
1274.86
1296.41
1315.28
1332.77
1349.14
1363.18
1377.05
1390.12
1402.05
1413.69
1424.55
1434.80
1445.00
1455.40
1466.03
1476.39
- 0.345
- 0.534
- 0.647
- 0.721
- 0.755
- 0.770
- 0.769
- 0.756
- 0.717
- 0.674
- 0.622
- 0.565
- 0.504
- 0.439
- 0.369
- 0.305
- 0.221
- 0.143
- 0.074
- 57.43
- 92.89
- 117.11
- 132.59
- 141.78
- 145.86
- 146.13
- 143.62
- 138.06
- 130.56
- 120.96
- 110.34
- 98.44
- 85.82
- 72.75
- 58.99
- 44.29
- 28.88
- 14.85
T = 308.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
0.7495
0.7988
0.8496
0.9015
0.9493
0.800798
0.820050
0.836779
0.851001
0.863525
0.874202
0.883914
0.892622
0.900097
0.907224
0.913830
0.919666
0.925146
0.930097
0.934564
0.938857
0.942846
0.946696
0.949996
1145.77
1175.23
1202.14
1225.90
1247.79
1266.94
1284.68
1301.29
1315.53
1329.52
1342.65
1354.57
1366.13
1376.79
1386.71
1396.35
1405.94
1415.30
1423.89
- 0.374
- 0.583
- 0.710
- 0.790
- 0.828
- 0.843
- 0.844
- 0.831
- 0.789
- 0.743
- 0.685
- 0.623
- 0.555
- 0.485
- 0.411
- 0.345
- 0.256
- 0.168
- 0.086
- 68.15
- 110.17
- 138.90
- 157.13
- 168.00
- 172.85
- 173.30
- 170.53
- 164.23
- 155.61
- 144.55
- 132.27
- 118.48
- 103.79
- 88.52
T = 298.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
0.7495
0.7988
0.8496
0.9015
0.9493
0.809138
0.828107
0.844596
0.858631
0.870971
0.881529
0.891123
0.899708
0.907093
0.914128
0.920659
0.926429
0.931853
0.936738
0.941147
0.945376
0.949301
0.953098
0.956375
1179.25
1208.33
1234.91
1258.41
1280.07
1299.03
1316.61
1333.06
1347.13
1361.03
1374.11
1386.01
1397.58
1408.34
1418.43
1428.35
1438.34
1448.34
1457.85
- 0.355
- 0.550
- 0.668
- 0.743
- 0.776
- 0.791
- 0.792
- 0.779
- 0.739
- 0.695
- 0.641
- 0.582
- 0.519
- 0.453
- 0.382
- 0.318
- 0.231
- 0.148
- 0.072
- 60.83
- 98.38
- 124.10
- 140.47
- 150.21
- 154.58
- 154.96
- 152.41
- 146.63
- 138.81
- 128.79
- 117.66
- 105.18
- 91.93
- 78.18
- 63.62
- 47.99
- 31.48
- 16.26
- 72.29
- 54.82
- 36.21
- 18.83
T = 313.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.796577
0.815971
0.832814
0.847155
0.859757
0.870579
0.880309
0.889068
0.896587
0.903761
0.910416
0.916285
0.921790
1129.25
1158.86
1185.95
1209.83
1231.86
1251.19
1268.98
1285.64
1299.97
1314.06
1327.26
1339.19
1350.76
- 0.384
- 0.599
- 0.729
- 0.813
- 0.851
- 0.874
- 0.870
- 0.856
- 0.812
- 0.765
- 0.706
- 0.641
- 0.570
- 72.11
- 116.48
- 146.82
- 166.03
- 177.47
- 182.71
- 183.07
- 180.09
- 173.46
- 164.42
- 152.79
- 139.83
- 125.28
T = 303.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.804983
0.824091
0.840700
0.854824
0.867256
1162.46
1191.72
1218.47
1242.09
1263.86
- 0.365
- 0.567
- 0.689
- 0.767
- 0.803
- 64.42
- 104.13
- 131.34
- 148.62
- 158.92
123

S. S. Bittencourt et al.
Table 3 (continued)
Table 3 (continued)
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
x1
q/g cm
DjS /TPa
x1
q/g cm
DjS /TPa
0
0
0
0
0
0
.7008
0.926775
0.931259
0.935592
0.939614
0.943490
0.946824
1361.43
1371.34
1380.88
1390.37
1399.61
1408.08
- 0.498
- 0.420
- 0.353
- 0.262
- 0.172
- 0.088
- 109.82
- 93.72
- 76.58
- 58.12
- 38.47
- 20.12
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.805264
0.824666
0.840380
0.852485
0.853510
0.874326
0.883020
0.890757
0.897008
0.903073
0.908403
0.913298
0.917707
0.921393
0.925222
0.928531
0.931773
0.934364
0.937021
1162.68
1192.25
1217.40
1237.43
1239.15
1275.87
1291.22
1305.26
1316.83
1328.26
1338.56
1347.99
1356.77
1364.14
1372.09
1379.14
1386.39
1392.51
1399.73
- 0.379
- 0.609
- 0.753
- 0.839
- 0.846
- 0.895
- 0.919
- 0.902
- 0.874
- 0.828
- 0.768
- 0.707
- 0.631
- 0.556
- 0.470
- 0.386
- 0.313
- 0.195
- 0.097
- 65.96
- 107.69
- 134.38
- 149.86
- 150.96
- 164.30
- 164.32
- 160.36
- 154.35
- 145.60
- 135.15
- 123.15
- 109.82
- 96.63
.7495
.7988
.8496
.9015
.9493
x
1
n-butylammonium propanoate ? (1 - x
1
) ethanol
T = 293.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0502
.1008
.1507
.1961
.2002
.3003
.3500
.4015
.4484
.4995
.5498
.6004
.6514
.6980
.7504
.7997
.8502
.8987
.9488
0.813587
0.832702
0.848231
0.860157
0.861170
0.881795
0.890397
0.897944
0.904098
0.910085
0.915360
0.920184
0.924536
0.928166
0.931929
0.935181
0.938369
0.940938
0.943596
1196.65
1225.96
1250.94
1270.84
1272.56
1309.00
1324.34
1338.29
1349.80
1361.20
1371.49
1380.97
1389.84
1397.34
1405.56
1412.99
1420.79
1427.72
1436.07
- 0.364
- 0.580
- 0.719
- 0.798
- 0.805
- 0.859
- 0.885
- 0.860
- 0.831
- 0.787
- 0.731
- 0.672
- 0.599
- 0.527
- 0.442
- 0.359
- 0.288
- 0.176
- 0.088
- 59.66
- 97.03
- 121.02
- 134.89
- 135.89
- 147.72
- 147.70
- 143.89
- 138.29
- 130.22
- 120.61
- 109.62
- 97.44
- 85.40
- 71.30
- 57.50
- 43.27
- 28.82
- 14.59
- 81.07
- 65.77
- 49.86
- 33.52
- 17.16
T = 308.15 K
0.801054
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
1145.87
1175.57
1200.82
1220.90
1222.62
1259.47
1274.86
1288.97
1300.57
1312.04
1322.37
1331.83
1340.61
1347.94
1355.83
1362.80
1369.91
1375.77
1382.68
- 0.387
- 0.623
- 0.768
- 0.859
- 0.866
- 0.911
- 0.936
- 0.923
- 0.894
- 0.848
- 0.785
- 0.723
- 0.645
- 0.568
- 0.480
- 0.395
- 0.321
- 0.202
- 0.101
- 69.53
- 113.57
- 141.69
- 157.99
- 159.14
- 173.16
- 173.18
- 169.11
- 162.81
- 153.65
- 142.70
- 130.15
- 116.16
- 102.29
- 85.94
0.820592
0.836394
0.848616
0.849648
0.870557
0.879313
0.887151
0.893439
0.899558
0.904913
0.909851
0.914289
0.918002
0.921859
0.925196
0.928468
0.931084
0.933762
T = 298.15 K
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.809442
0.828707
0.844320
0.856332
0.857349
0.878028
0.886681
0.894354
0.900556
0.906579
0.911884
0.916740
0.921121
0.924781
0.928579
0.931858
0.935071
0.937644
0.940297
1179.60
1209.04
1234.11
1254.08
1255.80
1292.40
1307.71
1321.70
1333.25
1344.65
1354.93
1364.37
1373.18
1380.59
1388.65
1395.85
1403.31
1409.77
1417.49
- 0.371
- 0.595
- 0.736
- 0.818
- 0.825
- 0.872
- 0.898
- 0.880
- 0.852
- 0.807
- 0.749
- 0.688
- 0.614
- 0.541
- 0.456
- 0.372
- 0.300
- 0.184
- 0.090
- 62.65
- 102.16
- 127.49
- 142.17
- 143.22
- 155.82
- 155.81
- 151.97
- 146.21
- 137.81
- 127.81
- 116.34
- 103.61
- 91.01
- 69.84
- 53.06
- 35.74
- 18.37
T = 313.15 K
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.796798
1129.19
1159.01
1184.31
1204.52
1206.25
1243.26
1258.68
1272.85
- 0.394
- 0.637
- 0.789
- 0.879
- 0.886
- 0.947
- 0.959
- 0.944
- 73.41
- 119.87
- 149.44
- 166.65
- 167.86
- 182.72
- 182.58
- 178.28
0.816486
0.832436
0.844718
0.845758
0.866959
0.875653
0.883524
- 76.22
- 61.68
- 46.61
- 31.22
- 15.93
T = 303.15 K
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 3 (continued) Table 3 (continued)
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
x1
q/g cm
DjS /TPa
x1
q/g cm
DjS /TPa
0
0
0
0
0
0
0
0
0
0
0
.4484
0.889843
0.896029
0.901421
0.906381
0.910868
0.914603
0.918492
0.921854
0.925152
0.927798
0.930500
1284.54
1296.08
1306.47
1315.88
1324.68
1331.99
1339.88
1346.83
1353.83
1359.63
1366.22
- 0.911
- 0.867
- 0.802
- 0.737
- 0.659
- 0.579
- 0.490
- 0.402
- 0.326
- 0.206
- 0.104
- 171.69
- 162.12
- 150.63
- 137.36
- 122.68
- 108.08
- 90.90
- 73.97
- 56.25
- 38.03
- 19.52
0.7898
0.8493
0.8997
0.9427
0.902185
0.904354
0.905981
0.907409
1372.93
1379.39
1384.92
1389.93
- 0.355
- 0.255
- 0.159
- 0.108
- 62.41
- 44.96
- 30.03
- 17.46
.4995
.5498
.6004
.6514
.6980
.7504
.7997
.8502
.8987
.9488
T = 303.15 K
0.805441
0.0502
0.1004
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.7459
0.7898
0.8493
0.8997
0.9427
1167.36
1198.50
1223.73
1244.54
1262.38
1277.08
1289.48
1300.87
1310.05
1319.37
1326.59
1333.15
1339.66
1344.36
1350.89
1355.66
1361.83
1367.06
1371.76
- 0.393
- 0.620
- 0.763
- 0.845
- 0.895
- 0.915
- 0.902
- 0.879
- 0.842
- 0.784
- 0.733
- 0.674
- 0.599
- 0.542
- 0.450
- 0.370
- 0.269
- 0.171
- 0.114
- 76.13
- 120.13
- 146.54
- 161.48
- 168.90
- 170.59
- 167.53
- 161.44
- 154.48
- 143.61
- 133.15
- 121.22
- 107.45
- 96.42
0.823258
0.836929
0.847729
0.856687
0.863893
0.869995
0.875443
0.879512
0.883737
0.886935
0.889849
0.892623
0.894565
0.897134
0.898874
0.901066
0.902701
0.904125
x
1
n-butylammonium hexanoate ? (1 - x
1
) ethanol
T = 293.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0502
.1004
.1505
.2005
.2513
.3007
.3511
.4035
.4492
.5038
.5503
.5979
.6491
.6883
.7459
.7898
.8493
.8997
.9427
0.813699
0.831217
0.844657
0.855276
0.864084
0.871181
0.877166
0.882513
0.886510
0.890675
0.893808
0.896669
0.899391
0.901284
0.903788
0.905488
0.907640
0.909279
0.910702
1201.39
1232.38
1257.54
1278.31
1296.14
1310.83
1323.15
1334.50
1343.73
1353.08
1360.35
1367.06
1373.75
1378.65
1385.54
1390.64
1397.39
1403.28
1408.68
- 0.378
- 0.595
- 0.731
- 0.809
- 0.857
- 0.878
- 0.864
- 0.841
- 0.806
- 0.752
- 0.702
- 0.645
- 0.573
- 0.515
- 0.423
- 0.345
- 0.247
- 0.160
- 0.111
- 68.57
- 108.20
- 132.04
- 145.53
- 152.23
- 153.71
- 150.77
- 145.10
- 138.74
- 128.78
- 119.21
- 108.36
- 95.86
- 85.88
- 70.66
- 58.74
- 42.21
- 28.19
- 16.43
- 79.56
- 66.30
- 47.82
- 31.98
- 18.59
T = 308.15 K
0.801260
0.0502
0.1004
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.7459
0.7898
0.8493
0.8997
0.9427
1150.53
1181.72
1206.99
1227.81
1245.67
1260.39
1272.82
1284.24
1293.41
1302.71
1309.95
1316.49
1322.96
1327.63
1334.05
1338.73
1344.67
1349.65
1354.07
- 0.400
- 0.633
- 0.779
- 0.863
- 0.913
- 0.934
- 0.922
- 0.898
- 0.861
- 0.799
- 0.748
- 0.689
- 0.612
- 0.554
- 0.462
- 0.381
- 0.281
- 0.181
- 0.121
- 80.24
- 126.57
- 154.35
- 170.03
- 177.84
- 179.62
- 176.47
- 170.12
- 162.82
- 151.42
- 140.50
- 128.00
- 113.55
- 101.99
- 84.25
0.819230
0.833020
0.843915
0.852952
0.860219
0.866388
0.871882
0.875988
0.880239
0.883476
0.886422
0.889218
0.891186
0.893785
0.895544
0.897770
0.899420
0.900849
T = 298.15 K
0.0502
0.1004
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.7459
0.809588
0.827254
0.840807
0.851514
0.860397
0.867545
0.873589
0.878987
0.883019
0.887215
0.890379
0.893264
0.896013
0.897934
0.900468
1184.33
1215.39
1240.58
1261.38
1279.20
1293.90
1306.26
1317.64
1326.83
1336.17
1343.41
1350.00
1356.58
1361.37
1368.04
- 0.386
- 0.607
- 0.746
- 0.826
- 0.875
- 0.895
- 0.881
- 0.858
- 0.822
- 0.766
- 0.715
- 0.657
- 0.584
- 0.527
- 0.434
- 72.25
- 114.00
- 139.09
- 153.31
- 160.35
- 161.95
- 158.96
- 153.11
- 146.46
- 136.07
- 126.07
- 114.66
- 101.54
- 91.06
- 70.30
- 50.78
- 33.99
- 19.73
T = 313.15 K
0.0502
0.1004
0.1505
0.797034
1133.82
1165.07
1190.49
- 0.405
- 0.644
- 0.793
- 84.36
- 133.15
- 162.54
0.815162
0.829077
- 75.02
123

S. S. Bittencourt et al.
Table 3 (continued)
Table 3 (continued)
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
-3
-1
u/m s
E
m
3
V /cm mol
-1
-1
x1
q/g cm
DjS /TPa
x1
q/g cm
DjS /TPa
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.2005
0.840069
0.849189
0.856532
0.862762
0.868287
0.872433
0.876735
0.880000
0.882977
0.885795
0.887786
0.890418
0.892178
0.894451
0.896127
0.897574
1211.22
1229.09
1243.85
1256.29
1267.81
1276.97
1286.25
1293.52
1300.07
1306.52
1311.17
1317.50
1322.17
1327.93
1332.73
1336.94
- 0.879
- 0.931
- 0.953
- 0.940
- 0.913
- 0.875
- 0.813
- 0.761
- 0.700
- 0.621
- 0.563
- 0.469
- 0.384
- 0.286
- 0.186
- 0.126
- 178.85
- 187.04
- 188.96
- 185.66
- 179.09
- 171.43
- 159.46
- 148.05
- 134.96
- 119.81
- 107.69
- 89.03
0.6000
0.6482
0.6992
0.7519
0.7967
0.8464
0.8918
0.9408
0.880190
0.882077
0.883738
0.885282
0.886439
0.887601
0.888537
0.889563
1374.67
1380.67
1386.31
1391.59
1396.06
1400.62
1404.58
1408.84
- 0.565
- 0.528
- 0.456
- 0.384
- 0.314
- 0.233
- 0.147
- 0.083
- 125.59
- 112.18
- 97.04
- 80.77
- 66.78
- 50.76
- 35.85
- 19.70
.2513
.3007
.3511
.4035
.4492
.5038
.5503
.5979
.6491
.6883
.7459
.7898
.8493
.8997
.9427
T = 303.15 K
0.806257
0.0499
0.0999
0.1999
0.2486
0.2988
0.3490
0.4001
0.4528
0.5013
0.5492
0.6000
0.6482
0.6992
0.7519
0.7967
0.8464
0.8918
0.9408
1178.70
1216.81
1269.44
1287.95
1303.51
1316.16
1327.09
1336.71
1344.46
1351.40
1357.65
1363.57
1369.12
1374.29
1378.63
1383.05
1386.89
1391.00
- 0.378
- 0.585
- 0.786
- 0.848
- 0.850
- 0.837
- 0.806
- 0.761
- 0.704
- 0.666
- 0.582
- 0.546
- 0.474
- 0.404
- 0.334
- 0.251
- 0.164
- 0.094
- 95.52
- 146.30
- 188.98
- 194.98
- 194.72
- 189.86
- 181.79
- 170.98
- 159.37
- 146.95
- 132.20
- 118.12
- 102.21
- 85.10
0.823276
0.844807
0.852014
0.857733
0.862418
0.866362
0.869767
0.872407
0.874791
0.876832
0.878746
0.880429
0.882001
0.883176
0.884352
0.885295
0.886316
- 74.40
- 53.81
- 36.07
- 20.95
x
1
n-butylammonium decanoate ? (1 - x
1
) ethanol
T = 293.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0499
.0999
.1999
.2486
.2988
.3490
.4001
.4528
.5013
.5492
.6000
.6482
.6992
.7519
.7967
.8464
.8918
.9408
0.814410
0.831076
0.852193
0.859241
0.864889
0.869434
0.873292
0.876628
0.879210
0.881545
0.883535
0.885396
0.887030
0.888551
0.889692
0.890851
0.891799
0.892828
1212.70
1250.68
1303.30
1321.83
1337.41
1350.07
1361.05
1370.71
1378.49
1385.57
1391.93
1398.05
1403.79
1409.22
1413.82
1418.53
1422.66
1427.10
- 0.362
- 0.557
- 0.751
- 0.809
- 0.818
- 0.799
- 0.769
- 0.726
- 0.671
- 0.636
- 0.553
- 0.515
- 0.444
- 0.372
- 0.302
- 0.225
- 0.147
- 0.089
- 86.07
- 131.97
- 170.83
- 176.33
- 176.15
- 171.68
- 164.35
- 154.51
- 143.92
- 132.67
- 119.27
- 106.53
- 92.11
- 76.65
- 63.35
- 48.14
- 34.00
- 18.69
- 70.36
- 53.49
- 37.80
- 20.79
T = 308.15 K
0.802130
0.0499
0.0999
0.1999
0.2486
0.2988
0.3490
0.4001
0.4528
0.5013
0.5492
0.6000
0.6482
0.6992
0.7519
0.7967
0.8464
0.8918
0.9408
1161.88
1200.03
1252.67
1271.18
1286.74
1299.38
1310.32
1319.93
1327.69
1334.62
1340.84
1346.71
1352.18
1357.26
1361.51
1365.83
1369.59
1373.53
- 0.385
- 0.597
- 0.803
- 0.865
- 0.866
- 0.854
- 0.823
- 0.777
- 0.718
- 0.680
- 0.594
- 0.556
- 0.484
- 0.414
- 0.344
- 0.262
- 0.173
- 0.101
- 100.62
- 154.01
- 198.74
- 205.00
- 204.70
- 199.58
- 191.13
- 179.78
- 167.63
- 154.60
- 139.13
- 124.33
- 107.60
- 89.61
0.819327
0.841083
0.848367
0.854137
0.858885
0.862873
0.866318
0.868984
0.871397
0.873462
0.875398
0.877105
0.878703
0.879896
0.881094
0.882047
0.883076
x
1
n-butylammonium decanoate ? (1 - x
1
) ethanol
T = 298.15 K
0
0
0
0
0
0
0
0
0
0
.0499
.0999
.1999
.2486
.2988
.3490
.4001
.4528
.5013
.5492
0.810348
0.827177
0.848514
0.855637
0.861322
0.865935
0.869834
0.873204
0.875814
0.878173
1195.64
1233.69
1286.32
1304.83
1320.41
1333.06
1344.00
1353.64
1361.39
1368.38
- 0.370
- 0.569
- 0.768
- 0.827
- 0.833
- 0.816
- 0.786
- 0.741
- 0.685
- 0.648
- 90.69
- 138.96
- 179.71
- 185.44
- 185.24
- 180.58
- 172.88
- 162.57
- 151.48
- 139.65
- 74.11
- 56.37
- 39.87
- 21.91
T = 313.15 K
0.0499 0.797959
1145.19
- 0.391
- 106.08
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 3 (continued) Table 4 Experimental densities, viscosities, deviations in viscosity
and excess Gibbs energy of activation of viscous flow for the binary
-3
-1
u/m s
E
m
3
-1
-1
x1
q/g cm
V /cm mol
DjS /TPa
mixtures (ionic liquids ? ethanol) at different temperatures
-
3
ÃE
-1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0999
0.815290
0.837345
0.844686
0.850563
0.855331
0.859367
0.862857
0.865524
0.867973
0.870076
0.872036
0.873762
0.875384
0.876596
0.877814
0.878785
0.879831
1183.38
1236.02
1254.56
1270.13
1282.74
1293.72
1303.39
1311.13
1318.03
1324.27
1330.11
1335.54
1340.51
1344.72
1348.93
1352.63
1356.48
- 0.604
- 0.820
- 0.881
- 0.888
- 0.870
- 0.838
- 0.792
- 0.726
- 0.688
- 0.602
- 0.564
- 0.490
- 0.419
- 0.349
- 0.266
- 0.177
- 0.104
- 162.15
- 209.07
- 215.61
- 215.29
- 209.82
- 200.97
- 189.11
- 176.30
- 162.60
- 146.40
- 130.84
- 113.26
- 94.29
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
.1999
.2486
.2988
.3490
.4001
.4528
.5013
.5492
.6000
.6482
.6992
.7519
.7967
.8464
.8918
.9408
x
1
n-butylammonium acetate ? (1 - x
1
) ethanol
T = 293.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
0.813263
0.832102
0.848466
0.862423
0.874707
0.885200
0.894717
0.903249
0.910587
0.917584
0.924078
0.929818
1.9579
- 54.39 0.38
2.9662 - 107.48 0.62
4.4641 - 162.00 0.81
6.5988 - 215.01 0.96
9.6006 - 268.12 1.05
13.546
19.183
26.717
36.528
50.388
69.471
94.020
- 318.24 1.09
- 367.56 1.12
- 414.91 1.10
- 458.43 1.06
- 500.11 1.01
- 537.84 0.93
- 568.23 0.83
- 589.83 0.73
- 599.57 0.62
- 593.57 0.51
- 567.25 0.39
- 508.81 0.28
- 408.75 0.15
- 249.77 0.08
- 78.00
- 59.30
- 41.96
0.935210 128.45
0.940062 173.54
0.944437 233.11
0.948632 313.72
0.952534 428.09
0.956331 585.41
0.959627 796.94
- 23.06
E
-2
Standard uncertainties
3
cm mol , u(DjS) = 2.05 TPa , u(T) = 0.02 K, u(p) = 1 kPa, and
1
m
u are: u(x ) = 0.003, u(V ) = 3 9 10
0.7495
.7988
-1
-1
0
-4
-3
the combined expanded uncertainty U
c
is U
(u) = 2.01 m s with 0.95 level of confidence (k = 2). All the
experiments were carried out at 93.2 kPa pressure with u(p) = 1 kPa
c
(q) = 3 9 10 g cm ;
-1
0.8496
0.9015
U
c
0
.9493
T = 298.15 K
1
7
1
.62 (2H, m, H-4), 1.38 (2H, m, H-5), 0.94 (3H, t, H-6),
?
13
.52 (3H, s, NH3 ); C-NMR (CDCl , 150 MHz, ppm): d
0.0501
0.0992
0.1500
0.2001
0.809138
0.828107
0.844596
0.858631
0.870971
0.881529
0.891123
0.899708
0.907093
0.914128
0.920659
0.926429
1.7628
2.6453
- 37.61 0.39
- 74.26 0.64
3
78.55 (C, C-1), 30.34(CH , C-2), 39.34 (CH , C-3), 24.36
3
2
3.9442 - 111.83 0.84
5.7747 - 148.27 1.01
8.3159 - 184.67 1.11
(
CH , C-4), 19.98 (CH , C-5), 13.72 (CH , C-6).
2 2 3
n-Butylammonium propanoate (N4Pro)
0.2511
.3001
0
11.613
16.258
22.395
30.316
41.245
56.165
75.117
- 218.89 1.16
- 252.39 1.19
- 284.33 1.18
- 313.42 1.15
- 341.03 1.10
- 365.54 1.02
- 384.71 0.92
- 397.64 0.82
- 402.26 0.70
- 396.23 0.58
- 376.18 0.46
- 334.34 0.34
- 266.46 0.19
- 160.99 0.11
Reagents: n-Butylamine and propanoic acid. Reaction
1
temperature 20 °C and reaction time 24 h. H-NMR
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.7008
(
CDCl , 600 MHz, ppm): d 2.17 (2H, m, H-2), 1.06 (3H, t,
3
H-3), 2.82 (2H, t, H-4), 1.62 (2H, m, H-5), 1.36 (2H, m,
? 13
H-6), 0.93 (3H, t, H-7), 7.35 (3H, s, NH3 ); CNMR
(
CDCl , 150 MHz, ppm): d 182.22 (C, C-1), 30.76 (CH ,
3
2
C-2), 10.49 (CH , C-3), 39.38 (CH , C-4), 30.27 (CH ,
3
0.931853 101.07
0.936738 134.50
0.941147 177.71
0.945376 235.43
0.949301 316.08
0.953098 423.70
0.956375 565.63
2
2
C-5), 19.83 (CH , C-6), 13.61 (CH , C-7).
2
3
0
0
0
0
0
.7495
.7988
.8496
.9015
.9493
n-Butylammonium hexanoate (N4Hex)
Reagents: n-Butylamine and hexanoic acid. Reaction
1
temperature 20 °C and reaction time 24 h. H-NMR
(CDCl3, 600 MHz, ppm): d 2.14 (2H, t, H-2), 1.55 (2H, m,
H-3), 1.29 (2H, m, H-4), 1.31 (2H, m, H-5), 0.89 (3H, t,
T = 303.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.804983
0.824091
0.840700
0.854824
0.867256
1.5907
- 26.64 0.40
- 52.58 0.67
- 79.11 0.88
H-6), 2.79 (2H, t, H-7), 1.60 (2H, m, H-8), 1.38 (2H, m,
2.3701
3.4966
?
13
H-9), 0.93 (3H, t, H-10), 6.88 (3H, s, NH3 ); C-NMR
CDCl3, 150 MHz, ppm): d 180.75 (C, C-1), 37.74 (CH2,
C-2), 26.01 (CH , C-3), 31.89 (CH , C-4), 22.57 (CH2,
(
5.0805 - 104.76 1.06
7.2414 - 130.31 1.16
2
2
123

S. S. Bittencourt et al.
Table 4 (continued)
q/g cm
Table 4 (continued)
-3
ÃE
-1
-3
ÃE
-1
x1
g/mPa s
Dg/mPa s DG /kJ mol
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.3001
0.877855
0.887521
0.896168
0.903597
0.910676
0.917244
0.923046
0.928497
10.004
13.875
18.933
25.365
34.116
45.902
60.680
80.632
- 154.25 1.22
- 177.51 1.26
- 199.56 1.26
- 219.46 1.23
- 238.14 1.18
- 254.41 1.10
- 266.76 1.00
- 274.47 0.90
- 276.50 0.77
- 270.71 0.65
- 255.60 0.52
- 225.26 0.39
- 177.97 0.23
- 105.04 0.14
0.7008
0.7495
0.7988
0.8496
0.9015
0.9493
0.926775
0.931259
68.081
86.621
- 139.02 0.90
- 134.79 0.77
- 125.68 0.62
- 109.39 0.47
- 85.01 0.29
- 49.23 0.17
.3500
.3999
.4483
.4987
.5503
.6002
.6511
.7008
.7495
.7988
.8496
.9015
.9493
0.935592 110.24
0.939614 141.48
0.943490 181.15
0.946824 230.97
1 1
x n-butylammonium propanoate ? (1 - x ) ethanol
T = 293.15 K
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
T = 298.15 K
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.933416 105.68
0.937856 137.93
0.942119 179.85
0.946073 237.81
0.949893 313.37
0.953173 412.25
0.813587
0.832702
0.848231
0.860157
0.861170
0.881795
0.890397
0.897944
0.904098
0.910085
0.915360
0.920184
1.9796
3.0713
- 47.39 0.44
- 94.93 0.74
4.6327 - 141.31 0.98
6.6190 - 182.87 1.14
6.8598 - 186.59 1.16
14.241
20.034
28.145
38.002
52.127
70.681
95.782
- 275.32 1.37
- 317.17 1.40
- 358.59 1.40
- 393.73 1.37
- 428.62 1.31
- 458.43 1.22
- 481.93 1.12
- 498.50 0.98
- 504.36 0.85
- 495.92 0.71
- 471.48 0.55
- 421.06 0.39
- 338.64 0.26
- 212.88 0.10
T = 308.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0501
.0992
.1500
.2001
.2511
.3001
.3500
.3999
.4483
.4987
.5503
.6002
.6511
.7008
.7495
.7988
.8496
.9015
.9493
0.800798
0.820050
0.836779
0.851001
0.863525
0.874202
0.883914
0.892622
0.900097
0.907224
0.913830
0.919666
0.925146
0.930097
1.4431
- 19.31 0.41
- 38.08 0.69
- 57.24 0.91
- 75.70 1.10
- 94.03 1.21
2.1299
3.1117
4.4916
6.3403
8.6725 - 111.14 1.27
0.924536 128.12
0.928166 167.00
0.931929 225.80
0.935181 297.57
0.938369 396.49
0.940938 525.39
0.943596 699.28
11.940
16.139
21.386
28.444
37.884
49.492
64.974
84.221
- 127.64 1.33
- 143.18 1.33
- 157.11 1.30
- 170.02 1.25
- 181.02 1.17
- 189.17 1.07
- 193.84 0.96
- 194.31 0.84
- 189.19 0.71
- 177.73 0.57
- 155.41 0.43
- 121.77 0.26
- 71.63 0.15
0.809442
0.828707
0.844320
0.856332
0.857349
0.878028
0.886681
0.894354
0.900556
0.906579
0.911884
0.916740
1.7801
2.7327
- 34.30 0.43
- 68.67 0.74
0.934564 108.61
0.938857 139.59
0.942846 182.03
0.946696 236.26
0.949996 305.30
4.0853 - 102.14 0.99
5.7876 - 132.06 1.16
6.0010 - 134.73 1.19
12.221
17.045
23.717
31.756
43.137
57.921
77.639
- 198.31 1.40
- 228.08 1.44
- 257.38 1.45
- 282.03 1.42
- 306.24 1.36
- 326.59 1.28
- 342.16 1.18
- 352.44 1.05
- 354.85 0.92
- 345.00 0.79
- 328.14 0.60
- 290.47 0.44
- 232.28 0.29
- 144.56 0.12
T = 313.15 K
0.0501
0.0992
0.1500
0.2001
0.2511
0.3001
0.3500
0.3999
0.4483
0.4987
0.5503
0.6002
0.6511
0.796577
0.815971
0.832814
0.847155
0.859757
0.870579
0.880309
0.889068
0.896587
0.903761
0.910416
0.916285
0.921790
1.3029
- 14.28 0.41
- 28.10 0.72
- 42.22 0.93
- 55.75 1.14
- 69.15 1.26
- 81.62 1.32
- 93.54 1.38
- 104.68 1.39
- 114.60 1.37
- 123.63 1.32
- 131.22 1.24
- 136.58 1.14
- 139.44 1.03
1.9306
2.7771
3.9876
5.5777
7.5595
10.321
13.851
18.177
23.986
31.580
40.899
53.009
0.921121 102.88
0.924781 132.96
0.928579 179.39
0.931858 230.62
0.935071 303.52
0.937644 395.46
0.940297 518.14
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 4 (continued) Table 4 (continued)
-3
ÃE
-1
-3
ÃE
-1
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
T = 303.15 K
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.883524
0.889843
0.896029
0.901421
0.906381
0.910868
0.914603
0.918492
14.769
19.299
25.609
33.492
43.745
56.373
70.954
92.003
- 105.36 1.59
- 114.75 1.57
- 123.61 1.52
- 130.69 1.45
- 135.47 1.35
- 137.98 1.22
- 137.24 1.08
- 131.77 0.93
- 122.91 0.74
- 106.68 0.56
- 83.65 0.38
- 50.62 0.17
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.805264
0.824666
0.840380
0.852485
0.853510
0.874326
0.883020
0.890757
0.897008
0.903073
0.908403
0.913298
0.917707
1.6030
2.4388
3.6143
5.0840
5.2772
10.545
14.589
20.123
26.731
35.985
47.928
63.608
83.440
- 25.30 0.43
- 50.61 0.75
- 75.21 1.00
- 97.15 1.18
- 99.09 1.21
- 145.50 1.44
- 167.07 1.49
- 188.16 1.50
- 205.75 1.48
- 222.84 1.42
- 236.91 1.34
- 247.35 1.24
- 253.82 1.11
- 254.47 0.98
- 247.08 0.83
- 232.81 0.65
- 204.98 0.48
- 162.50 0.32
- 100.23 0.14
0.921854 115.51
0.925152 146.74
0.927798 184.15
0.930500 232.08
1 1
x n-butylammonium hexanoate ? (1 - x ) ethanol
T = 293.15 K
0.0502
0.1004
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.7459
0.7898
0.8493
0.8997
0.9427
T = 298.15 K
0.0502
0.1004
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.921393 106.84
0.925222 141.31
0.928531 181.02
0.931773 234.93
0.934364 302.40
0.937021 390.55
0.813699
0.831217
0.844657
0.855276
0.864084
0.871181
0.877166
0.882513
0.886510
0.890675
0.893808
2.1631
- 54.74 0.72
3.5827 - 109.07 1.21
5.6956 - 162.50 1.59
8.7712 - 214.96 1.87
13.117
18.877
27.219
38.270
50.888
71.315
93.666
- 267.03 2.05
- 316.03 2.14
- 363.68 2.21
- 410.82 2.18
- 448.83 2.11
- 489.06 2.01
- 518.30 1.88
- 541.69 1.73
- 557.62 1.54
- 561.35 1.39
- 549.95 1.15
- 523.08 0.96
- 456.66 0.68
- 358.98 0.45
- 233.83 0.27
T = 308.15 K
0.0502
0.1008
0.1507
0.1961
0.2002
0.3003
0.3500
0.4015
0.4484
0.4995
0.5498
0.6004
0.6514
0.6980
0.7504
0.7997
0.8502
0.8987
0.9488
0.801054
0.820592
0.836394
0.848616
0.849648
0.870557
0.879313
0.887151
0.893439
0.899558
0.904913
0.909851
0.914289
0.918002
1.4471
- 18.96 0.43
- 37.90 0.77
- 56.28 1.01
- 72.63 1.20
- 74.05 1.24
2.1936
3.2075
4.4794
4.6586
0.896669 123.08
0.899391 163.98
0.901284 203.76
0.903788 279.12
0.905488 354.69
0.907640 487.20
0.909279 640.78
0.910702 813.73
9.1479 - 108.45 1.47
12.561
17.179
22.648
30.248
39.900
52.471
68.325
86.728
- 124.32 1.53
- 139.74 1.54
- 152.48 1.53
- 164.71 1.47
- 174.63 1.39
- 181.72 1.30
- 185.66 1.17
- 185.35 1.04
- 179.08 0.88
- 167.75 0.70
- 146.60 0.52
- 115.43 0.35
- 70.64 0.16
0.809588
0.827254
0.840807
0.851514
0.860397
0.867545
0.873589
0.878987
0.883019
0.887215
0.890379
0.893264
1.9396
3.1681
- 40.10 0.71
- 79.86 1.21
0.921859 113.38
0.925196 143.86
0.928468 184.63
0.931084 234.61
0.933762 298.88
4.9796 - 118.88 1.59
7.5920 - 157.10 1.88
11.234
16.005
22.847
31.797
41.929
58.324
75.940
98.980
- 194.93 2.06
- 230.41 2.16
- 264.73 2.23
- 298.56 2.20
- 325.65 2.13
- 353.84 2.04
- 374.15 1.91
- 389.94 1.77
- 400.08 1.58
- 401.50 1.43
T = 313.15 K
0
0
0
0
0
0
0
.0502
.1008
.1507
.1961
.2002
.3003
.3500
0.796798
0.816486
0.832436
0.844718
0.845758
0.866959
0.875653
1.3097
- 14.44 0.43
- 28.83 0.77
- 42.78 1.02
- 55.14 1.22
- 56.21 1.26
- 82.09 1.51
- 93.97 1.56
1.9706
2.8536
3.9590
4.1139
7.9710
10.839
0.896013 130.61
0.897934 161.18
123

S. S. Bittencourt et al.
Table 4 (continued)
q/g cm
Table 4 (continued)
-3
ÃE
-1
-3
ÃE
-1
x1
g/mPa s
Dg/mPa s DG /kJ mol
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
0
0
0
0
0
.7459
0.900468 218.27
0.902185 274.90
0.904354 372.61
0.905981 484.52
0.907409 607.94
- 391.43 1.18
- 370.60 0.99
- 321.47 0.71
- 250.66 0.48
- 162.38 0.28
0.1505
0.2005
0.2513
0.3007
0.3511
0.4035
0.4492
0.5038
0.5503
0.5979
0.6491
0.6883
0.7459
0.7898
0.8493
0.8997
0.9427
0.829077
0.840069
0.849189
0.856532
0.862762
0.868287
0.872433
0.876735
0.880000
0.882977
0.885795
0.887786
3.3984
5.0612
7.2415
10.116
13.994
18.975
24.539
33.170
42.340
53.989
69.361
84.101
- 50.12 1.60
- 65.98 1.91
- 81.60 2.09
- 96.00 2.22
- 109.79 2.29
- 123.16 2.26
- 133.57 2.21
- 144.08 2.13
- 151.18 2.01
- 156.19 1.87
- 158.75 1.68
- 157.74 1.54
- 151.66 1.29
- 141.60 1.09
- 120.75 0.79
- 91.75 0.54
- 58.34 0.32
.7898
.8493
.8997
.9427
T = 303.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0502
.1004
.1505
.2005
.2513
.3007
.3511
.4035
.4492
.5038
.5503
.5979
.6491
.6883
.7459
.7898
.8493
.8997
.9427
0.805441
0.823258
0.836929
0.847729
0.856687
0.863893
0.869995
0.875443
0.879512
0.883737
0.886935
0.889849
1.7481
- 29.77 0.72
- 59.25 1.21
- 88.12 1.59
2.8103
4.3685
6.6111 - 116.30 1.89
9.6611 - 144.16 2.07
13.655
19.309
26.634
34.850
48.264
62.072
80.265
- 170.16 2.18
- 195.18 2.25
- 219.73 2.22
- 239.25 2.16
- 259.07 2.08
- 273.52 1.95
- 284.26 1.80
- 290.70 1.62
- 290.78 1.47
- 282.14 1.22
- 265.86 1.03
- 229.16 0.74
- 177.08 0.50
- 114.12 0.29
0.890418 110.35
0.892178 135.78
0.894451 177.48
0.896127 224.11
0.897574 272.60
1 1
x n-butylammonium decanoate ? (1 - x ) ethanol
0.892623 104.96
0.894565 128.72
0.897134 172.39
0.898874 215.35
0.901066 288.26
0.902701 370.96
0.904125 460.11
T = 293.15 K
0.0499
0.0999
0.1999
0.2486
0.2988
0.3490
0.4001
0.4528
0.5013
0.5492
0.6000
0.6482
0.6992
0.7519
0.7967
0.8464
0.8918
0.9408
T = 298.15 K
0.0499
0.0999
0.1999
0.2486
0.2988
0.3490
0.4001
0.4528
0.5013
0.5492
0.814410
0.831076
0.852193
0.859241
0.864889
0.869434
0.873292
0.876628
0.879210
2.4453
- 51.19 1.12
4.3876 - 101.79 1.88
11.313
16.608
24.228
33.052
45.254
61.191
80.454
- 199.91 2.75
- 245.74 2.93
- 290.85 3.06
- 334.73 3.01
- 376.22 2.93
- 415.65 2.79
- 447.34 2.63
- 473.64 2.44
- 495.97 2.19
- 506.61 1.98
- 507.56 1.71
- 492.17 1.43
- 462.97 1.18
- 411.45 0.88
- 333.30 0.63
- 216.77 0.33
T = 308.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0502
.1004
.1505
.2005
.2513
.3007
.3511
.4035
.4492
.5038
.5503
.5979
.6491
.6883
.7459
.7898
.8493
.8997
.9427
0.801260
0.819230
0.833020
0.843915
0.852952
0.860219
0.866388
0.871882
0.875988
0.880239
0.883476
0.886422
0.889218
1.5665
- 22.37 0.70
- 44.48 1.20
- 66.09 1.60
- 87.12 1.90
2.4997
3.8537
5.7735
0.881545 104.39
0.883535 135.47
0.885396 175.44
0.887030 228.11
0.888551 298.85
0.889692 375.05
0.890851 478.81
0.891799 604.66
0.892828 772.68
8.3596 - 107.86 2.08
11.727
16.408
22.408
29.162
39.828
51.113
65.653
85.004
- 127.12 2.20
- 145.59 2.27
- 163.64 2.24
- 177.81 2.19
- 192.22 2.10
- 202.26 1.98
- 209.55 1.84
- 213.69 1.65
- 212.95 1.50
- 205.72 1.25
- 192.90 1.06
- 165.38 0.76
- 126.73 0.52
- 80.99 0.31
0.810348
0.827177
0.848514
0.855637
0.861322
0.865935
0.869834
0.873204
0.875814
0.878173
2.1852
3.8623
- 36.83 1.12
- 73.15 1.89
0.891186 103.73
0.893785 137.39
0.895544 170.34
0.897770 225.18
0.899420 286.94
0.900849 352.43
9.7012 - 143.27 2.76
14.057
20.296
27.393
37.142
49.753
64.853
83.282
- 175.88 2.94
- 207.78 3.08
- 238.80 3.02
- 267.87 2.95
- 295.30 2.81
- 317.05 2.66
- 334.94 2.47
T = 313.15 K
0
0
.0502
.1004
0.797034
0.815162
1.4160
2.2251
- 16.99 0.71
- 33.77 1.20
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
Table 4 (continued)
q/g cm
Table 4 (continued)
-3
ÃE
-1
-3
ÃE
-1
x1
g/mPa s
Dg/mPa s DG /kJ mol
x1
q/g cm
g/mPa s
Dg/mPa s DG /kJ mol
0
0
0
0
0
0
0
0
.6000
0.880190 107.23
0.882077 137.57
0.883738 177.23
0.885282 230.64
0.886439 285.12
0.887601 360.48
0.888537 450.51
0.889563 569.06
- 349.62 2.22
- 355.88 2.01
- 355.00 1.75
- 341.61 1.48
- 321.12 1.21
- 283.54 0.91
- 228.00 0.65
- 146.69 0.35
0.0999
0.1999
0.2486
0.2988
0.3490
0.4001
0.4528
0.5013
0.5492
0.6000
0.6482
0.6992
0.7519
0.7967
0.8464
0.8918
0.9408
0.815290
0.837345
0.844686
0.850563
0.855331
0.859367
0.862857
0.865524
0.867973
0.870076
0.872036
0.873762
2.7138
6.2770
8.8340
12.190
16.293
21.511
28.042
35.673
44.793
56.138
70.342
87.720
- 29.45 1.92
- 57.23 2.77
- 69.92 2.97
- 82.30 3.07
- 93.93 3.07
- 104.73 3.01
- 114.72 2.87
- 122.29 2.73
- 128.16 2.55
- 132.75 2.30
- 133.65 2.10
- 132.27 1.82
- 125.73 1.54
- 116.68 1.28
- 101.22 0.97
- 80.28 0.70
- 50.22 0.38
.6482
.6992
.7519
.7967
.8464
.8918
.9408
T = 303.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0499
.0999
.1999
.2486
.2988
.3490
.4001
.4528
.5013
.5492
.6000
.6482
.6992
.7519
.7967
.8464
.8918
.9408
0.806257
0.823276
0.844807
0.852014
0.857733
0.862418
0.866362
0.869767
0.872407
0.874791
0.876832
1.9575
3.4096
- 26.92 1.12
- 53.40 1.89
8.3560 - 104.30 2.76
11.974
17.121
22.906
30.737
40.817
52.725
67.110
85.644
- 127.86 2.95
- 150.74 3.09
- 172.98 3.04
- 193.69 2.97
- 213.05 2.83
- 228.23 2.68
- 240.55 2.49
- 250.41 2.25
- 253.97 2.04
- 252.56 1.77
- 242.61 1.49
- 226.56 1.23
- 198.90 0.93
- 158.88 0.67
- 101.57 0.36
0.875384 110.78
0.876596 133.85
0.877814 164.90
0.878785 200.07
0.879831 245.50
1
Standard uncertainties u are: u(x ) = 0.003, u(T) = 0.02 K, u(p) = 1
ÃE
-1
kPa, u
expanded uncertainty U
with 0.95 level of confidence (k = 2). All the experiments were car-
ried out at 93.2 kPa pressure with u(p) = 1 kPa
r
(Dg) = 0.16, u(DG ) = 0.16 kJ mol , and the combined
-4
-3
c
c
is U (q) = 3 9 10 g cm ; Ucr(g) = 0.09
0.878746 108.99
0.880429 138.91
0.882001 178.29
0.883176 219.32
0.884352 274.76
0.885295 340.13
0.886316 424.82
C-5), 14.03 (CH3, C-6), 39.33 (CH2, C-7), 30.48 (CH2,
C-8), 19.88 (CH2, C-9), 13.62 (CH3, C-10).
n-Butylammonium decanoate (N4Dec)
T = 308.15 K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0499
.0999
.1999
.2486
.2988
.3490
.4001
.4528
.5013
.5492
.6000
.6482
.6992
.7519
.7967
.8464
.8918
.9408
0.802130
0.819327
0.841083
0.848367
0.854137
0.858885
0.862873
0.866318
0.868984
0.871397
0.873462
0.875398
1.7583
- 19.92 1.12
- 39.48 1.89
- 76.89 2.77
- 94.06 2.97
- 110.96 3.06
- 126.86 3.06
- 141.76 2.99
- 155.60 2.86
- 166.29 2.71
- 174.78 2.52
- 181.48 2.28
- 183.46 2.07
- 181.84 1.80
- 173.86 1.52
- 161.88 1.25
- 141.21 0.95
- 112.45 0.68
- 71.38 0.37
Reagents: n-Butylamine and decanoic acid. Reaction tem-
1
3.0173
7.2187
10.293
14.283
19.261
25.626
33.716
43.214
54.616
69.075
87.149
perature 20 °C and reaction time 24 h. H-NMR (CDCl3,
600 MHz, ppm): d 2.14 (2H, t, H-2), 1.55 (2H, m, H-3),
1.26(12H, m, from H-4 to H-9), 0.88(3H, t, H-10), 2.77
(
(
2H, t, H-11), 1.59 (2H, m, H-12), 1.36 (2H, m, H-13), 0.93
? 13
3H, t, H-14), 6.35 (3H, s, NH3 ); C-NMR (CDCl3,
1
2
2
2
3
50 MHz, ppm): d 181.05 (C, C-1), 37.69 (CH2, C-2),
6.52 (CH2, C-3), 30.78 (CH2, C-4), 29.70 (CH2, C-5),
9.59 (CH2, C-6), 29.36 (CH2, C-7), 26.07 (CH2, C-8),
2.56 (CH2, C-9), 14.19 (CH3, C-10), 39.47 (CH2, C-11),
1.82 (CH2, C-12), 19.76 (CH2, C-13), 13.54 (CH3, C-14).
0.877105 110.01
0.878703 139.91
0.879896 170.51
0.881094 211.87
0.882047 259.53
0.883076 320.99
Characterization in the liquid state
1
13
On analyzing the H-NMR and C-NMR spectra of the
synthesized IL (Figs. S19–S22) we observed that the
chemical displacements of the amino group of n-buty-
lamine was altered after the formation of n-butylammo-
nium ion. This shift was attributed to the protonation of the
amino group and the altered multiplicity of the amine
T = 313.15 K
.0499
0
0.797959
1.5855
- 14.90 1.12
123

S. S. Bittencourt et al.
Table 5 Coefficients A
j
of
3
/cm mol
-1
3
/cm mol
-1
3
/cm mol
-1
3
/cm mol
-1
3
/cm mol
-1
3
-1
T/K
A
0
A
1
A
2
A
3
A
4
r/cm mol
Eq. (6) and standard deviations,
r, for the excess molar volume
at different temperatures
x
1
n-butylammonium acetate ? (1 - x
1
) ethanol
- 0.83041
2
2
3
3
3
93.15 - 2.70585
1.73061
1.76457
1.81805
1.89360
1.97640
1.46692
1.53541
1.48978
1.46919
1.46540
- 1.38047
- 1.36152
- 1.48377
- 1.54672
- 1.57709
0.0078
0.0086
0.0084
0.0082
0.0084
98.15 - 2.78578
03.15 - 2.88641
08.15 - 2.97554
13.15 - 3.06536
- 0.89866
- 0.92710
- 0.94865
- 0.95850
) ethanol
x
2
2
3
3
3
1 1
n-butylammonium propanoate ? (1 - x
93.15 - 3.15032
98.15 - 3.22207
03.15 - 3.30431
08.15 - 3.37904
13.15 - 3.45156
1.82359
1.82390
1.87069
1.90601
2.00402
- 0.88930
- 0.91565
- 0.95853
- 0.93253
- 1.05737
1.43316
1.50991
1.47230
1.49952
1.45030
- 1.25757
- 1.34426
- 1.41216
- 1.54886
- 1.40736
0.0087
0.0093
0.0093
0.0097
0.0079
x
2
2
3
3
3
1
n-butylammonium hexanoate ? (1 - x
1
) ethanol
- 0.96175
93.15 - 3.04855
98.15 - 3.10360
03.15 - 3.17752
08.15 - 3.24418
13.15 - 3.29985
1.99649
2.01790
2.05627
2.10798
2.17710
1.50533
1.58651
1.54305
1.48917
1.44681
- 1.42738
- 1.26549
- 1.28316
- 1.36079
- 1.39641
0.0071
0.0071
0.0070
0.0070
0.0070
- 1.09068
- 1.17082
- 1.21211
- 1.23496
x
2
2
3
3
3
1 1
n-butylammonium decanoate ? (1 - x ) ethanol
93.15 - 2.72562
98.15 - 2.77803
03.15 - 2.85265
08.15 - 2.91055
13.15 - 2.95382
1.95927
1.96316
1.97739
2.02746
2.11501
- 1.41987
- 1.59226
- 1.68439
- 1.71502
- 1.81963
1.47802
1.59780
1.55755
1.50795
1.42783
- 0.73969
- 0.50659
- 0.59419
- 0.69286
- 0.59265
0.0110
0.0116
0.0118
0.0119
0.0120
Table 6 Coefficients A
j
of
-1
-1
-1
-1
-1
-1
T/K
A
0
/TPa
A
1
/TPa
A
2
/TPa
A
3
/TPa
4
A /TPa
r/TPa
Eq. (6) and standard deviations,
r, for the deviation in isentropic
compressibility at different
temperatures
x
1
n-butylammonium acetate ? (1 - x ) ethanol
1
293.15
298.15
303.15
308.15
313.15
- 522.21577
- 555.20595
- 588.39855
- 622.37084
- 657.60065
325.46699
339.37446
355.48740
373.59355
393.70919
- 156.77469
- 169.98714
- 182.20854
- 194.62783
- 206.79769
182.69973
192.37444
203.14710
215.28979
227.60469
- 149.41719
- 159.24878
- 171.41328
- 183.00608
- 195.84220
0.6612
0.6966
0.7341
0.7668
0.8085
1 1
x n-butylammonium propanoate ? (1 - x ) ethanol
293.15
298.15
303.15
308.15
313.15
- 521.51141
- 551.83455
- 582.97695
- 615.19916
- 648.97142
340.25180
353.90439
369.46755
386.66291
406.40829
- 171.32514
- 184.36682
- 197.40674
- 210.17513
- 223.57593
202.57570
210.37713
220.58748
232.88083
245.52183
- 161.14268
- 168.09037
- 176.95149
- 187.85552
- 199.57816
0.6222
0.6163
0.6350
0.6552
0.6919
x
1
n-butylammonium hexanoate ? (1 - x
1
) ethanol
- 224.18356
2
2
3
3
3
93.15
98.15
03.15
08.15
13.15
- 519.09937
- 548.41937
- 578.81022
- 610.35925
- 642.81383
373.01139
280.87580
297.87620
315.48439
334.28286
352.36596
- 235.44179
- 249.39912
- 263.25097
- 277.81464
- 292.19186
0.7893
0.8328
0.8785
0.9360
0.9623
389.43551
406.92154
425.43794
445.14824
- 235.73311
- 249.49524
- 264.19384
- 279.71860
1 1
x n-butylammonium decanoate ? (1 - x ) ethanol
293.15
298.15
303.15
308.15
313.15
- 578.61249
- 608.94323
- 640.63708
- 673.81820
- 708.74026
429.76619
- 298.52422
- 313.05731
- 328.21963
- 344.42495
- 361.56400
422.26794
447.26641
473.86116
501.73197
531.85933
- 358.89863
- 381.36572
- 405.35675
- 430.65659
- 457.05436
1.3270
1.4075
1.4849
1.5673
1.6661
450.44900
471.83210
494.44462
518.68243
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
-
2
hydrogen signal. Integration of hydrogens into the amine
and IL was confirmed by the presence of two and three
hydrogen signals in the spectra [27].
deviation in isentropic compressibility were 3 9 10
3
-1
-1
cm mol and 2.05 TPa , respectively. The temperature
was automatically kept constant with ± 0.02 K using the
Peltier device built in the densimeter. The viscosities of
pure components and their solutions were measured using a
viscometer manufactured by Anton Paar (Model SVM
3000/G2), which was calibrated with special oils. The
reproducibility in the viscosity measurements was ± 0.35%
and in the temperature measurements was ± 0.02 K. The
relative standard uncertainty in the viscosity measurements
was 0.09. The uncertainties in the deviation in viscosity
and excess Gibbs energy of activation of viscous were 16%
On comparing the signal of n-butylamine ion, it was
observed that the chemical displacement of the amino
group was 1.42 ppm in n-butylamine and in the range of
6
.35–7.52 ppm in ILs. The integrated signal of the amino
1
group in the H NMR spectrum also changed indicating the
presence of three hydrogens in ILs. It is also important to
highlight the presence of the signal on the carbonyl group
in the range of 178.55–182.22 ppm, representing an offset
due to the formation of the anion [6, 8, 28–30].
-
1
and 0.16 kJ mol , respectively.
Apparatus and procedures
The binary mixtures were prepared by weighting of the
pure components on a digital electronic analytical balance
(SHIMADZU AUY Series, Model AUY220) with preci-
sion of ± 0.0001 g. All the solutions were prepared in
The densities and speeds of sound of pure components and
their solutions were measured using a commercial density
and speed of sound analyzer manufactured by Anton Paar
3
10 cm stoppered glass bottles inside an inert atmosphere
(
Model DSA 5000), which was calibrated with air and
dry box and precautions were taken to minimize variations
in composition due to evaporation of alcohols or pickup of
water by ionic liquids. The uncertainty in mole fraction
was estimated to be ± 0.003.
high-purity water. The equipment measures the speed of
sound at a frequency of 3 MHz. The combined expanded
uncertainty in the density and speed of sound measure-
-
4
-3
-1
ments were ± 3 9 10 g cm and 2.01 m s , respec-
tively. The uncertainties in the excess molar volume and
j
Table 7 Coefficients A of
T/K
A
0
/mPa s
A
1
/mPa s
A
2
/mPa s
A
3
/mPa s
A
4
/mPa s
r/mPa s
Eq. (6) and standard deviations,
r, for the deviation in viscosity
at different temperatures
x
2
2
3
3
3
1
n-butylammonium acetate ? (1 - x
1
) ethanol
93.15 - 2005.88495 - 1533.87917 - 1021.22492 - 862.87365 - 536.13281 1.4875
98.15 - 1367.35121 - 1010.59788
- 643.62559 - 500.12504 - 293.57627 0.9135
- 420.91876 - 287.47330 - 143.34004 0.7036
03.15
08.15
13.15
- 954.23587
- 681.23650
- 495.30551
- 681.70405
- 467.45609
- 325.73683
- 272.50845 - 174.14117
- 180.80151 - 104.89028
- 84.41714 0.4334
- 44.61486 0.3498
x
1
n-butylammonium propanoate ? (1 - x
93.15 - 1717.55912 - 1249.03349
98.15 - 1227.39051 - 858.38631
03.15 - 892.72298 - 603.48031
08.15 - 659.84982
13.15 - 495.17757
1
) ethanol
2
2
3
3
3
- 762.95175 - 685.12274 - 488.07360 1.9205
- 484.20385 - 425.57032 - 319.98149 1.3556
- 328.29742 - 267.08661 - 191.43095 0.7985
- 219.13475 - 167.75426 - 120.98872 0.5462
- 429.26317
- 309.21510
- 148.24776 - 108.17945
1
) ethanol
- 78.78279 0.3624
x
2
2
3
3
3
1
n-butylammonium hexanoate ? (1 - x
93.15 - 1945.82626 - 1374.46053
- 837.41277 - 544.46792 - 255.83042 0.7015
- 562.21534 - 336.99805 - 145.02376 0.4731
98.15 - 1408.22393
03.15 - 1031.88757
- 963.49430
- 683.05522
- 488.66180
- 352.75252
- 382.64670 - 206.40079
- 260.18132 - 126.15350
- 75.29779 0.3459
- 38.27329 0.3196
- 17.91618 0.2624
08.15
13.15
- 765.15029
- 573.43681
- 178.46746
1
) ethanol
- 77.28695
x
2
2
3
3
3
1
n-butylammonium decanoate ? (1 - x
93.15 - 1787.97584 - 1206.55548
- 670.86619 - 450.88352 - 278.61079 1.1344
- 434.89571 - 267.58632 - 163.32458 0.7445
98.15 - 1267.34942
- 825.09895
- 575.01942
- 402.67839
- 284.74473
03.15
08.15
13.15
- 912.17741
- 664.61828
- 488.63760
- 294.63520 - 159.79548
- 87.95932 0.4441
- 52.48234 0.2802
- 24.83985 0.1794
- 197.99060
- 136.05415
- 99.66578
- 58.96118
123

S. S. Bittencourt et al.
Table 8 Coefficients A
j
of
-1
-1
-1
-1
-1
-1
T/K
A
0
/kJ mol
1
A /kJ mol
A
2
/kJ mol
A
3
/kJ mol
4
A /kJ mol
r/kJ mol
Eq. (6) and standard deviations,
r, for the excess Gibbs energy
of activation of viscous flow at
different temperatures
x
1
n-butylammonium acetate ? (1 - x
1
) ethanol
293.15
298.15
303.15
308.15
313.15
4.02468
4.38092
4.71034
4.99285
5.26664
- 2.68152
- 2.61657
- 2.56380
- 2.52243
- 2.45763
0.22488
- 0.76032
- 0.70926
- 0.63215
- 0.55948
- 0.50217
0.67772
0.67667
0.81189
0.72138
0.64107
0.0092
0.0085
0.0087
0.0095
0.0096
0.23102
0.19111
0.24074
0.27473
) ethanol
0.12733
0.45271
0.39754
0.45936
0.41239
x
2
2
3
3
3
1 1
n-butylammonium propanoate ? (1 - x
93.15
98.15
03.15
08.15
13.15
5.23302
5.45219
5.68350
5.89617
6.09689
- 2.89624
- 2.70779
- 2.62958
- 2.53007
- 2.41793
- 0.87784
- 0.76312
- 0.63859
- 0.56505
- 0.50208
0.41106
0.0087
0.0109
0.0077
0.0078
0.0081
- 0.17956
- 0.16002
- 0.20579
- 0.19222
x
1
n-butylammonium hexanoate ? (1 - x
1
) ethanol
1.33185
1.40631
1.34428
1.60226
1.63897
) ethanol
4.59459
4.68394
4.59570
4.40703
4.21383
2
2
3
3
3
93.15
98.15
03.15
08.15
13.15
8.07194
8.18838
8.32350
8.42579
8.54014
- 4.66447
- 4.53840
- 4.43010
- 4.35349
- 4.27193
- 0.90845
- 0.86270
- 0.81897
- 0.67406
- 0.59211
0.86694
0.74382
0.85298
0.39367
0.30088
0.0097
0.0097
0.0115
0.0092
0.0105
1 1
x n-butylammonium decanoate ? (1 - x
2
2
3
3
3
93.15
98.15
03.15
08.15
13.15
10.52484
10.62503
10.72633
10.83124
10.92411
- 7.42138
- 7.29619
- 7.25493
- 7.10381
- 6.97783
- 2.65535
- 2.65870
- 2.56614
- 2.68046
- 2.80377
0.59702
0.53813
0.67136
0.95254
1.36165
0.0148
0.0150
0.0144
0.0083
0.0086
Results and discussion
1
jS ¼
;
2
ð2Þ
q Á u
The experimental results for density, speed of sound,
excess molar volume and deviation in isentropic com-
pressibility as a function of the ionic liquid mole fraction
for the binary systems at different temperature are listed in
Table 3. The experimental results for viscosity, deviation
in viscosity and excess Gibbs energy of activation of vis-
cous flow are listed in Table 4. Figures S23–S34 show the
behavior of density, speed of sound and viscosity as a
function of mole fraction of ILs at different temperatures.
For all systems studied, the values of the properties
increase with increase in mole fraction of the ionic liquid
and decrease when the temperature increases.
in which q and u represents the density and speed of sound.
The deviations in isentropic compressibility (DjS) were
calculated using the following equation:
ꢀ
ꢁ
1
1
1
DjS ¼
À
x1
þ x2
;
ð3Þ
2
2
1
2
2
q Á u
q1 Á u
q2 Á u
in which x , q , and u represent the mole fractions, densities
i
i
i
and speed of sounds of pure components, respectively, q
and u are the density and speed of sound of mixture.
The deviations in viscosity were calculated using the
following equation:
E
m
Dg ¼ g À ðx1g þ x2g Þ;
ð4Þ
The excess molar volume (V ) was calculated using the
1
2
following equation:
in which x and g , represent the mole fractions and
i
i
E
V ¼ x1M1ð1=q À 1=q Þ þ x2M2ð1=q À 1=q Þ;
in which x , M and q represent the mole fraction, molar
ð1Þ
dynamic viscosities of pure components, respectively, g is
the dynamic viscosity of mixture.
m
1
2
i
i
i
The excess Gibbs energy of activation for viscous flow
*E
DG ) was calculated by:
masses and densities of the pure components, respectively,
(
and q is the density of liquid solution.
ÃE
DG =RT ¼ lnðg Á VÞ À x1 Á lnðg Á V1Þ À x2 Á lnðg Á V2Þ;
The isentropic compressibility (j ) was calculated using
1
2
S
the following equation:
ð5Þ
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
ꢂ
where N represents the number of data points and n is the
ꢃ
n
o
1=2
X
2
in which g represents the dynamic viscosity of mixture, g1
E
E
ðcalÞ
r ¼
Y
À Y
=ðN À nÞ
;
ð7Þ
ðexptÞ
and g are the dynamic viscosities of pure components, V is
2
the molar volume, R is the ideal gas constant and T is the
absolute temperature.
order of fitting polynomial.
The experimental results were fitted with a Redlich–
Kister type equation [31]:
E
m
ÃE
Figures 2–5 show the values of V , DjS, Dg, and DG
as a function of mole fraction of ionic liquids for the sys-
j¼n
X
E
m
j
tems studied at different temperatures. For all binary
mixtures, the values of VE and Dj are negative over the
Y ¼ x ð1 À x Þ
A ð2x À 1Þ ;
ð6Þ
1
1
j
1
S
j¼0
m
entire composition range at all investigated temperatures
and become more negative with increase in temperatures.
E
m
E
ÃE
in which Y represents V , Dj , Dg or DG , x is the mole
m
S
1
fraction of component 1, A is the adjustable coefficients
j
The results show asymmetrical curves with the minimum
E
obtained by least square method, and n is the degree of the
values between x = 0.30 and 0.35 for V , and x = 0.30
1
m
1
polynomial.
and 0.40 for Dj . The values of Dg are negative over the
S
E
m
ÃE
The coefficients A for V , DjS, Dg or DG are given in
j
entire composition range at all investigated temperatures
but become less negative with increase in temperatures.
The results show asymmetrical curves with the maximum
Tables 5–8, respectively, along with the corresponding
standard deviations calculated using the following
equation:
values between x = 0.65 and 0.70 for Dg.
1
a) 0.000
(b) 0.000
(
–
–
–
–
–
0.200
0.400
0.600
0.800
1.000
–
–
–
–
–
0.200
0.400
0.600
0.800
1.000
–1.200
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
c) 0.000
(d) 0.000
(
–
–
–
–
–
–
0.200
0.400
0.600
0.800
1.000
1.200
–
–
–
–
0.200
0.400
0.600
0.800
–1.000
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
Fig. 2 Excess molar volume as a function of mole fraction for the {x
ionic liquids ? (1 - x ) ethanol} binary mixtures at different tem-
peratures: square, 293.15 K; circle, 298.15 K; diamond, 303.15 K;
triangle, 308.15 K; cross, 313.15 K. Solid lines represent the
1
correlations using the Redlich–Kister equation. a n-butylammonium
acetate; b n-butylammonium propanoate; c n-butylammonium hex-
anoate; d n-butylammonium decanoate
1
123

S. S. Bittencourt et al.
0
0
–50
(a)
(b)
–
50
–
–
–
100
150
–100
–150
200
0
–200
0
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
(c)
(d)
–50
–50
–
–
–
100
150
200
–
–
–
100
150
200
–250
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
Fig. 3 Deviation in isentropic compressibility as a function of mole
fraction for the {x ionic liquids ? (1 - x ) ethanol} binary mixtures
at different temperatures: square, 293.15 K; circle, 298.15 K; dia-
mond, 303.15 K; triangle, 308.15 K; cross, 313.15 K. Solid lines
represent the correlations using the Redlich–Kister equation. a n-
butylammonium acetate; b n-butylammonium propanoate; c n-buty-
lammonium hexanoate; d n-butylammonium decanoate
1
1
ÃE
E
m
The values of DG are positive over the entire com-
position range at all investigated temperatures and become
negative values to V . Interstitial accommodation due to
the difference in molar volumes and free volume between
the components present in the mixtures should be another
more positive with increase in temperatures. The results
E
m
show asymmetrical curves with the maximum values
ÃE
effect that contributes to negative values of the V .
between x = 0.30 and 0.35 for DG .
Normally, specific interactions in mixtures, typically
hydrogen bond, decrease as the temperature increases,
while non-specific interactions can be neglected [33].
1
The behavior of the excess molar volume is a conse-
quence of the several opposing effects. The negative VE
m
E
m
values can result from strong chemical or specific inter-
actions between the compounds present in the mixtures or
structural effects arising from the geometrical fitting of one
component into the other due to differences in the molar
volume and free volume between the components. Protic
ionic liquids can form hydrogen bonds with proton
acceptors such as alcohols [32]. In the binary mixtures,
possibly there is a disruption of associated structure of the
pure liquid molecules through the breaking of hydrogen
bonds with subsequent formation of a complex interaction
between the ILs and ethanol. This fact should result in
Therefore, as the temperature increases, the V values also
increase due to a reduction in the hydrogen bond in the
mixtures. On the other hand, as the temperature increases,
the interactions of the pure components molecules are
reduced due to the increase in the kinetic energy. The
decrease interaction between pure compounds molecules
causes a greater packing efficiency between the molecules
of solute and solvent, so a contraction of the volume
E
E
m
increases. Consequently, V decreases. The decrease in V
m
with increasing temperature can be understood as a greater
accommodation of the molecules of ILs and ethanol when
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
0
100
200
300
400
500
600
700
0
100
200
300
400
500
(
a)
(b)
–
–
–
–
–
–
–
–
–
–
–
–
–600
0
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x
1
0
(
c)
(d)
–
–
–
–
–
–
–
100
200
300
400
500
600
700
–
–
–
–
–
100
200
300
400
500
–600
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
Fig. 4 Deviation in viscosity as a function of mole fraction for the {x
ionic liquids ? (1 - x ) ethanol} binary mixtures at different tem-
peratures: square, 293.15 K; circle, 298.15 K; diamond, 303.15 K;
triangle, 308.15 K; cross, 313.15 K. Solid lines represent the
1
correlations using the Redlich–Kister equation. a n-butylammonium
acetate; b n-butylammonium propanoate; c n-butylammonium hex-
anoate; d n-butylammonium decanoate
1
the complex is formed compared with the packing of the
molecules of the pure compounds. Consequently, there
would be a further reduction in the volume of the complex
formed when compared with the decrease in the molar
volume of the pure components.
the components present in the mixture regarding the hin-
drance that there would be under the pure compounds.
As we can observe in Fig. 4, the values of the Dg are
negative for all binary mixtures studied and become less
negative with increasing temperatures. The results reveal
that the viscosity of the mixture is lower than that of the
pure compounds and for this reason the fluidity of the
mixtures is higher. This indicates the predominance of
dispersion force in the mixtures studied.
The results of Dj are shown in Fig. 3. This properties
S
behavior in a similar way to the excess volume. Inter-
molecular interactions, differences in size and shapes of the
molecules of the compounds in the mixtures and fitting of
one component into the other structure lead to a more
compact structure, contributing to DjS negative. The
ÃE
Figure 5 indicates that DG values are positive and
they decrease as the temperature increases for all binary
magnitude of Dj decrease with increase in temperature
mixtures studied. According to other authors, the positive
ÃE
S
because the reduction in the volume of the complex formed
when compared with the decrease in the molar volume of
the pure components causes a great difficult to compress
DG values can be attributed to intermolecular interac-
tions and structural effects due to difference of the mole-
cules size present in the mixtures [34].
123

S. S. Bittencourt et al.
(
a) 1.60
(b) 1.80
1
1
1
0
0
0
0
0
.40
.20
.00
.80
.60
.40
.20
.00
1
.50
.20
1
0.90
0
.60
.30
0
0.00
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
(
c) 2.50
(d) 4.00
2
1
1
0
0
.00
.50
.00
.50
.00
3
2
1
.00
.00
.00
0.00
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x1
x1
Fig. 5 Excess Gibbs energy of activation of viscous flow as a
function of mole fraction for the {x ionic liquids ? (1 - x
ethanol} binary mixtures at different temperatures: square,
93.15 K; circle, 298.15 K; diamond, 303.15 K; triangle, 308.15 K;
cross, 313.15 K. Solid lines represent the correlations using the
Redlich–Kister equation. a n-butylammonium acetate; b n-butylam-
monium propanoate; c n-butylammonium hexanoate; d n-butylam-
monium decanoate
1
1
)
2
E
m
Conclusions
studied, the values of V , DjS and Dg were negative over
ÃE
the entire composition range, whereas DG values were
In this study, density, speed of sound and viscosity of
positive over the entire composition range. The thermo-
dynamic results suggest that the structural effects and
dispersion type interactions must outweigh other possible
effects present in the mixtures studied.
binary mixtures of ionic liquids (ILs) ? ethanol have been
measured as
a
function of composition at
T = (293.15–313.15) K and atmospheric pressure. The
ionic liquids studied were: {n-butylammonium acetate
Acknowledgements This work has been supported by the Funda c¸ a˜ o
Educacional Inaciana Padre Sab o´ ia de Medeiros (FEI), Universidade
Estadual de Campinas (UNICAMP), Funda c¸ a˜ o de Amparo a` Pesquisa
do Estado de S a˜ o Paulo (FAPESP) (Process No 2009/14556-5) and
Coordena c¸ a˜ o de Aperfei c¸ oamento de Pessoal de N ´ı vel Superior
(
N4Ace), n-butylammonium propanoate (N4Pro), n-buty-
lammonium hexanoate (N4Hex) and n-butylammonium
decanoate (N4Dec)). The ILs were synthesized by the
method of acid–base neutralization reaction using n-buty-
lamine and different acids (acetic acid, propanoic acid,
(CAPES). We thank Dr. Nivaldo Boralle for the NMR measurements
and Dr. Andreia Morandim-Giannetti for discussion of the results.
1
hexanoic acid, decanoic acid) and characterized using H-
1
NMR,
3
C-NMR and FTIR spectroscopy techniques.
E
Excess molar volume, V , deviation in isentropic com-
m
References
pressibility, Dj , deviation in viscosity, Dg, and excess
Gibbs energy of activation of viscous flow, DG , were
determined from experimental results and correlated with
S
ÃE
1. Cremer T. Ionic liquid bulk and interface properties. Basel:
Springer; 2013.
2
. Fang Z, Smith J, Qi RLX. Production of biofuels and chemicals
with ionic liquids. New York: Springer; 2014.
the Redlich–Kister polynomial equation. For all systems
1
23

Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with…
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