Static permittivities of n-propanol mixtures with ethanol, isomers of propanol, and butanol at temperature (288.15–308.15) K

Journal of Molecular Liquids 179 (2013) 72–77

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Static permittivities of n-propanol mixtures with ethanol, isomers of propanol, and butanol at temperature (288.15–308.15) K Dorota Chęcińska-Majak a, Adam Bald a,⁎, Ram Jeewan Sengwa b a b

Department of Physical Chemistry of Solutions, University of Łódź, 90-236 Łódź, Pomorska 163, Poland Dielectric Research Laboratory, Department of Physics, JNV University, Jodhpur 342 005, India

a r t i c l e

i n f o

Article history: Received 9 November 2012 Accepted 11 December 2012 Available online 27 December 2012 Keywords: Relative permittivity Alcohol–alcohol mixtures Molecular interactions in liquids

a b s t r a c t The relative static permittivities of six binary systems of n-propanol with ethanol, i-propanol, isomeric butanols are reported as a function of composition at temperatures 288.15 K; 293.15 K; 298.15 K; 303.15 K and 308.15 K. From the experimental results, the excess relative permittivity, εrE, the permittivity temperature coefficient, (∂lnεr / ∂T), and their excess values at the 298.15 K were calculated. The excess parameters have been fitted to the Redlich–Kister polynomial equation. The results on dielectric measurements were used in the analysis of the hydrogen bond intermolecular interactions occurring between the constituents of alcohol mixture, their dependence on the number of carbon atoms, and the position of the hydroxyl group in the structure of molecules (the type of alcohols). © 2012 Elsevier B.V. All rights reserved.

1. Introduction Dielectric studies of mixed solvents play an important role in the knowledge and understanding of intermolecular interactions in dipolar liquid mixtures. This applies to both, dipole–dipole interactions and hydrogen bonds formed in the mixture. The relative static permittivity, εr, and the calculated excess permittivity values can give information about the structural properties of polar solvents. The dependence of relative permittivity, εr, on temperature provides information about the dynamics of the microstructures [1]. Dipole moments of alcohol molecules depend on the polarity of the \OH group and the values for pure solvents are similar. Therefore, the changes in the dielectric permittivity as a function of the mixed solvent composition are mainly related to the intermolecular interactions. A review of the literature indicates that only a few works are devoted to the study of static dielectric of alcohol+alcohol mixtures [2–7]. In our previous papers we have presented the results of the systematic studies of the static relative permittivity of mixtures of methanol with aliphatic alcohols containing 2 to 4 carbon atoms in the molecule [5] and mixtures of four isomeric butanols [7]. This paper presents the results of the static permittivity mixtures propan-1-ol with other alcohols containing up to 4 carbon atoms in the molecule. Thus, this paper is a direct continuation of our previous works. In addition to research the relative static permittivity, some authors have used different methods for the research of the dielectric properties of mixtures of alcohol with an alcohol, such as time domain reflectometry (TDR) [8] or dielectric relaxation spectroscopy [9–11]. It should be emphasized, that these research

⁎ Corresponding author. Tel.: +48 0426355846. E-mail address: [email protected] (A. Bald). 0167-7322/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.molliq.2012.12.015

methods do not provide precise values of static permittivity, as shown in the work [5]. The purpose of this paper is to present the study of static permittivity of six binary mixtures of propan-1-ol (n-PrOH) with ethanol (EtOH), propan-2-ol (i-PrOH), butan-1-ol (n-BuOH), 2-methyl-propan-1-ol (i-BuOH), butan-2-ol (s-BuOH) and 2-methyl-propan-2-ol (t-BuOH) over the whole composition range at five temperatures (288.15– 308.15) K. 2. Experimental 2.1. Chemicals Analytical grade reagents purchased from Merck, Fluka, and Aldrich were used. All solvents were stored in dark bottles over molecular sieves (Sigma, 0.3–0.4 nm) to reduce water content. Before use, they were double distilled and degassed in an ultrasound bath. The purity of the alcohols were tested by a comparison of the densities, d, refractive indices, nD, relative permittivity, εr, and relative temperature coefficient, (∂lnεr / ∂T), at 298.15 K with their corresponding literature values (Table 1). The comparison shows a very reasonable agreement. 2.2. Measurements Measurements of relative permittivity were made by using a dielectrometer constructed in the Institute of Chemistry at the University of Łódź. For capacity measurement, a self-excited method was used. The method of the measurements and a detailed description of the apparatus are described in our previous paper [5]. The mixtures were prepared by weight with an accuracy of 0.0001 mol fraction.

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73

Table 1 Experimental and literature densities, d, refractive indices, nD, relative permittivity, εr, relative static permittivity temperature coefficient, (∂lnεr /∂T), for pure alcohols at 298.15 K. d /g · cm−3

Alcohol

εr

nD

Exp.

Lit.

Exp. a

EtOH

0.78510

0.78493 0.785095b 0.78517c

1.3594

n-PrOH

0.79960

1.3833

i-PrOH

0.78101

0.799770k 0.79962c 0.79957b 0.79960a 0.79975f 0.78089o 0.78126a

n-BuOH

0.80564

1.3974

i-BuOH

0.79774

s-BuOH

0.80214

t-BuOH

0.78077⁎

0.805737b 0.80575a 0.80582c 0.80589p 0.805901k 0.8060f 0.7978a 0.797874s 0.80241a 0.802487s 0.80237u 0.7812a 0.779479s⁎⁎

1.3751

1.3938 1.3953

1.3848⁎

Lit.

∂lnεr / ∂T

Exp. c

Lit.

Exp.

24.35

24.34 24.55h,a 24.35i

−0.00626

−0.00622j

20.45

20.33l 20.28n 20.45a 20.44i

−0.00670

−0.00650j −0.00674n

19.43

−0.00883

−0.00714j −0.00859n

1.39730f 1.39741a 1.3975r 1.39722k 1.3969c 1.3967l 1.39389a 1.3938t 1.39530a 1.3949t 1.39488u 1.3852a 1.3850t

17.58

19.41h 19.38n 19.92a 19.40i 17.51a,l 17.43i

−0.00782

−0.00771j

17.96

17.93h,a

−0.00829

−0.00860j

16.60

16.467w 16.56h,a 17.0i 12.47h,a

−0.01058

−0.00990v,x

−0.01637

−0.01460v,x

[12], b [13], c [14], d [15], e [16], f [17], g [18], h [19], i [20], j [21], k [22], l [23], m [24], n [4], o [25], p [26], r [27], s [28], t [29], ⁎ Values extrapolated from the dependence y = f(x2) for x2 = 1, where y are experimental densities or refractive indices. ⁎⁎ Value at 299.15 K.

a

Immediately before measuring the liquids were degassed in an ultrasonic cleaner and pre-heated to a temperature slightly higher than that used during the measurement. The uncertainty of the relative permittivity was estimated to be approximately ± 0.05. 3. Results and discussion The experimental values of relative permittivity for the investigated binary mixtures at (288.15, 293.15, 298.15, 303.15, and 308.15) K are reported in Table 2. From the experimental data of relative permittivity, the excess values, εrE, were calculated according to the following equation: E

εr ¼ εr −ðx1 ⋅ε r1 þ x2 ⋅εr2 Þ

ð1Þ

and afterwards they were fitted to the Redlich–Kister [34,35] equation to obtain the parameters ai:

E

εr ¼ x1 ⋅x2

n X

i

ai ðx2 −x1 Þ

ð2Þ

i¼0

where: x1, x2 — the mole fraction of components (1) and (2); εr1, εr2 — the static permittivity of components (1) and (2); and n — the degree of the polynomial. In order to determine these parameters the method of least squares was used. The adjustable parameters, ai, and the standard deviations, σ(εrE), are presented in Table 3. The values of εrE were used to determine the smooth values of relative permittivity, εr(s): E

εrðsÞ ¼ x1 ⋅εr1 þ x2 ⋅εr2 þ εr :

Lit.

1.3587 1.35922d 1.35931e 1.35941a,f 1.38310k 1.3827c 1.3831l 1.38370a,f 1.38283m 1.3752a,f 1.37444o

12.49⁎

g

ð3Þ

u

[30],

w

[31],

v

[32],

x

[33].

Fig. 1 shows the dependence of the relative permittivity as a function of the mole fraction for all six binary systems of alcohols at 298.15 K. The corresponding excess values, εrE, were presented in Fig. 2. The dependencies εr = f(x2) are monotonic, however, they show small deviations from the linearity, especially for mixtures n-PrOH+ MeOH (from Ref. [5]) and n-PrOH+t-BuOH. It is obvious that the decreasing or increasing character of curves is directly related to the value of εr for pure alcohol. The value of relative permittivity for the pure alcohols can be sorted in the order εr

EtOH

> εr > εr

nPrOH

tBuOH :

> εr

iPrOH

> εr

iBuOH

> εr

nBuOH

> εr

sBuOH

The εr values are therefore dependent on both the carbon chain length (becomes smaller with increasing chain length) and their type (the smallest for tertiary alcohol). Large and branched molecules have a reduced ability to form hydrogen bonds and the formation of intermolecular associates of linear type. The nature of changes of the relative permittivity in the function of the composition of the mixed solvent is more pronounced in the case of excess value of εr. As shown in Fig. 2, in the case of n-PrOH mixtures with alcohols of similar chain length the absolute εrE values are inconsiderable. This is particularly evident for mixtures of n-PrOH with i-PrOH for which εrE is practically comparable with an estimated uncertainty of εr. Slightly more negative values of excess εrE occur for mixtures of n-PrOH+ EtOH. However, the mixtures of n-PrOH with MeOH (from Ref. [5]) show clearly negative values of εrE. This is because the difference in the carbon chain length between the components of the mixture is considerable. A major impact in addition to the chain length is also a type of alcohol added to n-PrOH, which can be seen very well in the case of t-butanol. We note here the positive excess of εrE. This is probably due

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Table 2 Experimental values of relative permittivity, εr, for mixtures of alcohols in the function of the composition of the mixture. x2

εr

x2

T/K 288.15

T/K 293.15

298.15

308.15

288.15

298.15

303.15

308.15

19.78 19.98 20.16 20.31 20.48 20.66 20.82 20.97 21.11 21.27 21.43 21.58 21.74 21.93 22.12 22.32 22.52 22.78 23.00 23.32 23.60

19.13 19.33 19.53 19.68 19.85 20.01 20.18 20.30 20.45 20.58 20.74 20.87 21.02 21.19 21.37 21.58 21.77 22.03 22.25 22.59 22.87

0.0000 0.0523 0.0994 0.1474 0.2002 0.2511 0.3032 0.3498 0.4002 0.4496 0.5009 0.5506 0.5992 0.6525 0.7057 0.7512 0.8014 0.8500 0.9024 0.9515 1.0000

n-PrOH + i-BuOH 21.87 21.15 21.68 20.96 21.53 20.81 21.39 20.67 21.24 20.52 21.11 20.38 20.98 20.25 20.87 20.12 20.75 20.00 20.63 19.88 20.51 19.75 20.40 19.64 20.29 19.52 20.17 19.40 20.05 19.28 19.95 19.18 19.85 19.07 19.75 18.97 19.65 18.87 19.57 18.79 19.51 18.71

20.45 20.28 20.12 19.97 19.82 19.67 19.54 19.41 19.28 19.15 19.03 18.90 18.79 18.66 18.54 18.44 18.33 18.22 18.12 18.03 17.96

19.78 19.60 19.45 19.30 19.14 18.99 18.85 18.72 18.58 18.46 18.33 18.20 18.08 17.95 17.83 17.72 17.61 17.51 17.40 17.31 17.23

19.13 18.96 18.80 18.64 18.48 18.33 18.18 18.05 17.92 17.78 17.65 17.52 17.40 17.27 17.14 17.04 16.92 16.82 16.71 16.61 16.53

20.45 20.40 20.35 20.30 20.25 20.21 20.16 20.11 20.06 20.01 19.96 19.91 19.86 19.81 19.76 19.71 19.66 19.60 19.55 19.49 19.43

19.78 19.72 19.67 19.61 19.56 19.50 19.45 19.39 19.34 19.28 19.22 19.17 19.11 19.05 18.99 18.92 18.86 18.80 18.73 18.66 18.59

19.13 19.07 19.00 18.94 18.88 18.82 18.76 18.70 18.64 18.57 18.51 18.45 18.38 18.31 18.24 18.17 18.10 18.03 17.95 17.87 17.79

0.0000 0.0497 0.1013 0.1490 0.2000 0.2498 0.3000 0.3510 0.4021 0.4508 0.4984 0.5480 0.6010 0.6497 0.7015 0.7527 0.7997 0.8521 0.8920 0.9488 1.0000

n-PrOH + s-BuOH 21.87 21.15 21.66 20.93 21.45 20.71 21.27 20.53 21.07 20.32 20.89 20.14 20.71 19.96 20.54 19.77 20.37 19.60 20.22 19.43 20.07 19.27 19.92 19.10 19.76 18.93 19.61 18.77 19.46 18.59 19.31 18.42 19.16 18.26 18.99 18.07 18.85 17.91 18.66 17.70 18.47 17.51

20.45 20.23 20.01 19.80 19.60 19.41 19.23 19.03 18.85 18.67 18.50 18.32 18.13 17.95 17.76 17.57 17.39 17.18 17.03 16.80 16.60

19.78 19.55 19.32 19.12 18.91 18.72 18.52 18.32 18.13 17.95 17.77 17.58 17.37 17.18 16.97 16.76 16.57 16.35 16.18 15.95 15.75

19.13 18.90 18.65 18.45 18.24 18.04 17.84 17.64 17.44 17.25 17.06 16.86 16.64 16.43 16.21 15.99 15.78 15.55 15.38 15.14 14.94

20.45 20.28 20.11 19.94 19.79 19.62 19.47 19.32 19.17 19.02 18.88 18.74 18.59 18.47 18.33 18.20 18.07 17.95 17.82 17.70 17.58

19.78 19.61 19.44 19.28 19.12 18.96 18.80 18.66 18.51 18.36 18.22 18.07 17.93 17.80 17.66 17.53 17.40 17.28 17.15 17.03 16.91

19.13 18.96 18.80 18.63 18.47 18.32 18.17 18.01 17.87 17.71 17.58 17.42 17.28 17.16 17.01 16.88 16.75 16.63 16.49 16.39 16.26

0.0000 0.0504 0.1001 0.1489 0.1997 0.2503 0.3003 0.3497 0.4001 0.4499 0.4990 0.5501 0.6003 0.6498 0.7004 0.7499 0.8002 0.8498 0.9002 0.9501 1.0000

n-PrOH + t-BuOH 21.87 21.15 21.54 20.85 21.24 20.55 20.94 20.27 20.65 19.98 20.37 19.69 20.10 19.41 19.85 19.14 19.60 18.86 19.35 18.58 19.10 18.30 18.85 18.00 18.57 17.68 18.28 17.35 17.95 16.97 17.58 16.56 17.16 16.09 16.69 15.57 16.12 14.97 15.31⁎ 14.28 14.49⁎ 13.38⁎

20.45 20.18 19.90 19.63 19.34 19.06 18.77 18.49 18.19 17.89 17.58 17.25 16.90 16.53 16.12 15.67 15.17 14.62 13.99 13.28 12.49⁎

19.78 19.52 19.25 18.98 18.68 18.39 18.08 17.78 17.46 17.13 16.78 16.41 16.02 15.61 15.15 14.67 14.13 13.54 12.88 12.15 11.34

19.13 18.89 18.63 18.36 18.07 17.77 17.46 17.14 16.80 16.45 16.08 15.68 15.26 14.81 14.33 13.81 13.25 12.63 11.95 11.22 10.40

0.0000 0.0520 0.0995 0.1448 0.1966 0.2517 0.3042 0.3482 0.4017 0.4495 0.5027 0.5477 0.5978 0.6512 0.7016 0.7499 0.7999 0.8502 0.8979 0.9522 1.0000

n-PrOH + EtOH 21.87 21.15 22.02 21.33 22.19 21.49 22.33 21.64 22.52 21.82 22.70 22.00 22.90 22.18 23.06 22.34 23.26 22.52 23.45 22.70 23.66 22.89 23.84 23.06 24.05 23.26 24.28 23.47 24.50 23.68 24.72 23.89 24.95 24.11 25.18 24.36 25.42 24.58 25.68 24.87 25.92 25.12

20.45 20.64 20.81 20.96 21.15 21.32 21.49 21.63 21.82 21.97 22.15 22.30 22.50 22.69 22.89 23.09 23.31 23.54 23.80 24.08 24.35

0.0000 0.0513 0.1016 0.1535 0.1991 0.2510 0.3018 0.3500 0.4000 0.4514 0.5006 0.5494 0.5998 0.6510 0.6993 0.7499 0.7977 0.8502 0.9003 0.9493 1.0000

n-PrOH + i-PrOH 21.87 21.15 21.83 21.11 21.80 21.06 21.76 21.02 21.73 20.98 21.69 20.94 21.66 20.90 21.63 20.85 21.60 20.82 21.56 20.77 21.53 20.73 21.50 20.69 21.47 20.65 21.44 20.61 21.41 20.57 21.38 20.53 21.35 20.49 21.32 20.44 21.29 20.40 21.25 20.35 21.22 20.31

0.0000 0.0502 0.0998 0.1502 0.2001 0.2500 0.3004 0.3490 0.3988 0.4503 0.4988 0.5510 0.6005 0.6487 0.7003 0.7486 0.8006 0.8474 0.9011 0.9488 1.0000

n-PrOH + n-BuOH 21.87 21.15 21.69 20.97 21.52 20.80 21.35 20.64 21.19 20.47 21.03 20.32 20.87 20.16 20.72 20.01 20.58 19.86 20.43 19.71 20.29 19.57 20.14 19.43 20.01 19.29 19.88 19.16 19.75 19.03 19.62 18.90 19.49 18.77 19.38 18.65 19.25 18.52 19.13 18.40 19.01 18.28

⁎ Extrapolated value.

εr

303.15

293.15

D. Chęcińska-Majak et al. / Journal of Molecular Liquids 179 (2013) 72–77

1.50

Table 3 Coefficients of the Redlich–Kister equation and their standard deviations for excess relative permittivity, εrE, at 298.15 K. ai

n-PrOH + EtOH n-PrOH + i-PrOH n-PrOH + n-BuOH n-PrOH + i-BuOH n-PrOH + s-BuOH n-PrOH + t-BuOH

1.00

σ(εrE)

a0

a1

a2

−1.0399 0.0852 −0.5500 −0.7021 −0.1220 4.4345

−0.9025 0.0748 0.0373 −0.0349 0.4475 3.1474

−0.0026 0.0357 −0.0006 −0.3310 −0.1817 1.3412

0.007 0.003 0.004 0.006 0.005 0.003

0.50 0.00

ε rE

Mixture

75

-0.50 -1.00 -1.50 -2.00

to the steric barriers arising from the construction of t-butanol molecules and differences in the carbon chain length. In the case of t-butanol (solvent added to mixtures) the impact of competitive interactions of n-propanol+ t-butanol is negligible in comparison with the effects of interactions of n-propanol + n-propanol. In summary, for mixtures n-PrOH + t-BuOH, the values of εr are not additive and appear as a large maximum for the dependence εrE = f(x2). Further information about the intermolecular interactions provides analysis of changes of the relative permittivity temperature coefficient: ∂lnε r =∂T ¼ ∂εr =ðεr ∂T Þ:

ð4Þ

From the experimental values of εr, the relative values of the temperature coefficient, (∂lnεr / ∂T) (Table 4) and their excess values, (∂lnεr / ∂T)E, have been calculated. The Redlich–Kister procedure was used to calculate values of (∂lnεr / ∂T)E, in the same way as it was done previously (compare Eq. (2)):

E

ð∂ lnε r =∂T Þ ¼ x1 ⋅x2

n X

i

bi ðx2 −x1 Þ :

ð5Þ

i¼0

The coefficients of obtained polynomials and the standard deviations, σ(∂lnεr /∂T)E, were given in Table 5.

30.00

-2.50 0.0000

0.4000

0.6000

0.8000

1.0000

x2 Fig. 2. Excess relative permittivity, εrE, as a function of mole fraction for binary mixtures of alcohols at 298.15 K: —— n-PrOH + MeOH, bold – – – n-PrOH + EtOH, −∙∙ − n-PrOH + i-PrOH, bold —— n-PrOH + i-BuOH, −∙ − n-PrOH + n-BuOH, – – – n-PrOH + s-BuOH, ———— n-PrOH + t-BuOH. Plots were based on the coefficients given in Table 3.

Smooth values of the relative temperature coefficient can be calculated from the equation: E

ð∂lnεr =∂T Þs ¼ x1 ⋅ð∂lnεr =∂T Þ1 þ x2 ⋅ð∂lnεr =∂T Þ2 þ ð∂lnεr =∂T Þ :

ð6Þ

The plot of the relative temperature coefficient as a function of composition of the mixed solvent at the temperature 298.15 K is shown in Fig. 3. If the addition of the second component of the mixture does not cause drastic changes in the relative temperature coefficient, (∂lnεr /∂T), we can expect that the amount of hydrogen bonding between n-propanol (1) and the other alcohol (2) changes slightly. On the other hand, if the competitiveness of the interactions between 1 and 2 components in relation to 1–1 is smaller, the changes should be more visible and more different from linearity. Fig. 3 shows, that in the case of mixtures of n-propanol with other alcohols the deviations from additivity are dependent on the difference between the carbon chain length of mixed components and the type of the alcohol. The conclusions about deviations from additivity are more visible on the figure showing the excess values of the temperature coefficient, (∂lnεr / ∂T)E, as a function of the composition for the mixtures of alcohols at 298.15 K (Fig. 4). As can be seen, the excess of the temperature coefficient, also depends on the carbon chain length of mixed components. The dependencies are approximately the following: E

ð∂lnε r =∂T Þ

25.00

0.2000

E

MeOH E

E

nBuOH

and ð∂lnεr =∂T Þ

sBuOH

iPrOH :

εr

> ð∂lnεr =∂T Þ

> ð∂lnεr =∂T Þ

For mixtures of n-PrOH + EtOH, the concentration dependence of (∂lnεr / ∂T) E is a little more complex (present the minimum in EtOH rich-region and maximum in n-PrOH rich-region) and it is difficult to accurately classify this system. However, it is visible that the dependence is related to the location of the \OH group:

20.00

15.00

E

10.00 0.0000

ð∂lnεr =∂T Þ 0.2000

0.4000

0.6000

0.8000

E

tBuOH

> ð∂lnεr =∂T Þ

E

sBuOH

> ð∂lnεr =∂T Þ

nBuOH :

1.0000

x2 Fig. 1. Relative static permittivity, εr, as a function of the mole fraction for binary mixtures of alcohols at 298.15 K: —+— n-PrOH+MeOH, —◊— n-PrOH+EtOH, —□— n-PrOH+i-PrOH, —x— n-PrOH+i-BuOH, —▲—n-PrOH+n-BuOH, —○—n-PrOH+s-BuOH, —●—n-PrOH+ t-BuOH. The solid lines were obtained from the values calculated using Eq. (3).

Unfortunately, it is difficult to find here the right place for the system n-PrOH+ i-BuOH since the second component is a primary alcohol, but it has a branched carbon chain. One can only conclude that the branching of the carbon chain only slightly reduces the (∂lnεr / ∂T)E because (∂lnεr / ∂T) En-BuOH > (∂lnεr / ∂T) Ei-BuOH.

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Table 4 Values of relative temperature coefficient, (∂lnεr / ∂T), for each mixture at 298.15 K. n-PrOH + EtOH

n-PrOH + i-PrOH

n-PrOH + n-BuOH

n-PrOH + i-BuOH

n-PrOH + s-BuOH

n-PrOH + t-BuOH

x2

∂lnεr / ∂T · 103/K−1

x2

∂lnεr / ∂T · 103/K−1

x2

∂lnεr / ∂T · 103/K−1

x2

∂lnεr / ∂T · 103/K−1

x2

∂lnεr /∂T ·103/K−1

x2

∂lnεr /∂T · 103/K−1

0.0000 0.0520 0.0995 0.1448 0.1966 0.2517 0.3042 0.3482 0.4017 0.4495 0.5027 0.5477 0.5978 0.6512 0.7016 0.7499 0.7999 0.8502 0.8979 0.9522 1.0000

−6.69 −6.52 −6.39 −6.32 −6.32 −6.30 −6.32 −6.36 −6.44 −6.52 −6.59 −6.65 −6.74 −6.80 −6.83 −6.79 −6.82 −6.69 −6.66 −6.42 −6.26

0.0000 0.0513 0.1016 0.1535 0.1991 0.2510 0.3018 0.3500 0.4000 0.4514 0.5006 0.5494 0.5998 0.6510 0.6993 0.7499 0.7977 0.8502 0.9003 0.9493 1.0000

−6.69 −6.77 −6.86 −6.94 −7.03 −7.10 −7.19 −7.27 −7.37 −7.46 −7.56 −7.65 −7.77 −7.89 −8.01 −8.14 −8.26 −8.38 −8.53 −8.66 −8.82

0.0000 0.0502 0.0998 0.1502 0.2001 0.2500 0.3004 0.3490 0.3988 0.4503 0.4988 0.5510 0.6005 0.6487 0.7003 0.7486 0.8006 0.8474 0.9011 0.9488 1.0000

−6.69 −6.72 −6.76 −6.81 −6.86 −6.90 −6.94 −7.00 −7.06 −7.13 −7.16 −7.25 −7.33 −7.36 −7.47 −7.52 −7.58 −7.65 −7.73 −7.73 −7.81

0.0000 0.0523 0.0994 0.1474 0.2002 0.2511 0.3032 0.3498 0.4002 0.4496 0.5009 0.5506 0.5992 0.6525 0.7057 0.7512 0.8014 0.8500 0.9024 0.9515 1.0000

−6.69 −6.70 −6.78 −6.88 −6.96 −7.06 −7.16 −7.25 −7.34 −7.43 −7.50 −7.61 −7.68 −7.76 −7.84 −7.89 −7.98 −8.03 −8.10 −8.20 −8.28

0.0000 0.0497 0.1013 0.1490 0.2000 0.2498 0.3000 0.3510 0.4021 0.4508 0.4984 0.5480 0.6010 0.6497 0.7015 0.7527 0.7997 0.8521 0.8920 0.9488 1.0000

−6.69 −6.82 −6.98 −7.11 −7.21 −7.33 −7.46 −7.61 −7.77 −7.94 −8.12 −8.33 −8.59 −8.85 −9.13 −9.44 −9.71 −9.99 −10.17 −10.44 −10.60

0.0000 0.0504 0.1001 0.1489 0.1997 0.2503 0.3003 0.3497 0.4001 0.4499 0.4990 0.5501 0.6003 0.6498 0.7004 0.7499 0.8002 0.8498 0.9002 0.9501 1.0000

−6.69 −6.57 −6.55 −6.57 −6.68 −6.83 −7.05 −7.35 −7.71 −8.12 −8.62 −9.21 −9.82 −10.53 −11.28 −12.08 −12.94 −13.94 −14.98 −15.66 −16.57

Table 5 Coefficients of the Redlich–Kister equation and their standard deviations for relative temperature coefficient excess values, (∂lnεr / ∂T)E, at 298.15 K. Mixture

n-PrOH + EtOH n-PrOH + i-PrOH n-PrOH + n-BuOH n-PrOH + i-BuOH n-PrOH + s-BuOH n-PrOH + t-BuOH

E

3

σ(∂lnεr / ∂T) · 10 /K

bi b0 · 103

b1 · 103

b2 · 103

−0.523 0.776 0.227 −0.170 2.040 12.035

−3.844 0.208 −0.301 −0.443 −0.878 −2.438

0.437 −0.010 0.063 0.001 −2.254 −2.244

−1

0.025 0.010 0.017 0.019 0.021 0.070

4. Conclusions The relative static permittivity of the binary alcohol mixtures (n-propanol with ethanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, and tert-butanol) at five temperatures (every 5K in the interval from 288.15 K to 308.15 K) have been measured over the entire composition range. The relations of εr, εrE, (∂lnεr /∂T), (∂lnεr /∂T)E values as the function of the composition for the mixed solvents studied here at 298.15 K have been analyzed. It has been established that the above dielectric parameter values (directly connected with the H-bond interactions between molecules of different alcohols), depend on the molecular carbon chain length of the added component and the type of alcohol (primary, secondary, or tertiary).

-0.0050 0.0035

-0.0070

0.0025

(∂lnεr/∂T) E/K-1

(∂lnεr/∂T)/K-1

-0.0090

-0.0110

-0.0130

0.0015

0.0005 -0.0150

-0.0170 0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

x2 Fig. 3. Relative temperature coefficient, (∂lnεr /∂T), as a function of the mole fraction for mixtures of alcohols at 298.15 K: —+—n-PrOH+MeOH, —◊—n-PrOH+EtOH, —□— n-PrOH+i-PrOH, —x—n-PrOH+i-BuOH, —▲—n-PrOH+n-BuOH, —○—n-PrOH+s-BuOH, —●—n-PrOH+t-BuOH. The solid lines were obtained from the values calculated using Eq. (6).

-0.0005 0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

x2 Fig. 4. Excess values of the relative temperature coefficient, (∂lnεr / ∂T)E, as a function of the mole fraction for mixtures of alcohols at 298.15 K: —— n-PrOH + MeOH, bold – – – n-PrOH + EtOH, −∙∙ − n-PrOH + i-PrOH, bold —— n-PrOH + i-BuOH, −∙ − n-PrOH + n-BuOH, – – – n-PrOH + s-BuOH, ———— n-PrOH + t-BuOH. Plots were carried out using the coefficients contained in Table 5.

D. Chęcińska-Majak et al. / Journal of Molecular Liquids 179 (2013) 72–77

References [1] A. Catenaccio, C. Magallanes, Chemical Physics Letters 395 (2004) 196–198. [2] A. Ghanadzadeh, H. Ghanadzadeh, R. Sariri, L. Ebrahimi, The Journal of Chemical Thermodynamics 37 (2005) 357–362. [3] S. Taniewska-Osińska, A. Piekarska, A. Bald, A. Szejgis, Journal of the Chemical Society, Faraday Transactions 1 (85) (1989) 3709–3715. [4] S. Taniewska-Osińska, A. Piekarska, A. Bald, A. Szejgis, Physics and Chemistry of Liquids 21 (1990) 217–230. [5] A. Chmielewska, M. Żurada, K. Klimaszewski, A. Bald, Journal of Chemical & Engineering Data 54 (2009) 801–806. [6] R.J. Sengwa, S. Sankhla, N. Shinyashiki, Journal of Solution Chemistry 37 (2008) 137–153. [7] K. Klimaszewski, A. Boruń, A. Bald, R. Sengwa, Journal of Chemical & Engineering Data 57 (2012) 3164–3170. [8] B.G. Lone, P.B. Undre, S.S. Patil, P.W. Khirade, S.C. Mehrotra, Journal of Molecular Liquids 141 (2008) 47–53. [9] J. Lou, K. Paravastu, P.E. Laibinis, T.A. Hatton, Journal of Physical Chemistry A 101 (1997) 9892–9899. [10] D.J. Denney, R.H. Cole, Journal of Chemical Physics 23 (1955) 1767–1772. [11] N.H. Ayachit, M.T. Hosamani, D.K. Deshpande, Physics and Chemistry of Liquids 49 (2011) 639–647. [12] J.A. Riddick, W.B. Bunger, T.K. Sakano, Organic Solvents, 4th edition Wiley, New York, 1986. [13] H. Ogawa, S. Murakami, Journal of Solution Chemistry 16 (1987) 315–326. [14] H. Iloukhani, M. Fattahi, Journal of Molecular Liquids 171 (2012) 37–42. [15] M. Iglesias, B. Orge, M.M. Pineiro, B.E. Cominges, G. Marino, J. Tojo, Journal of Chemical & Engineering Data 43 (1998) 776–780. [16] L. Albuquerque, C. Ventura, R. Gonςalves, Journal of Chemical & Engineering Data 41 (1996) 685–688. [17] TRC Thermodynamic Tables; Thermodynamic Research Center, Texas A&M University, College Station, TX, 1994. [18] O.W. Kolling, Analytical Chemistry 58 (1986) 870–873. [19] W. Dannhauser III, Journal of Chemical Physics 40 (1964) 3058–3066.

77

[20] J.M.G. Barthel, H. Krienke, W. Kunz, Physical chemistry of electrolyte solutions: modern aspects, Topics in physical chemistry, vol. 5, Springer, 1998. [21] J.L.M. Abboud, R. Notario, Critical compilation of scales of solvent effects, report to IUPAC Commission on Phys. Org. Chem., from: Marcus, Y, The Properties of Solvents, John Wiley & Sons Ltd, New York, 1998. [22] L.F. Sanz, J.A. Gonzalez, I.G. De La Fuente, J.C. Cobos, Journal of Molecular Liquids 172 (2012) 26–33. [23] N.V. Sastry, M.K. Valand, Journal of Chemical & Engineering Data 43 (1998) 152–157. [24] M. Iglesias, B. Orge, J. Tojo, Journal of Chemical & Engineering Data 41 (1996) 218–221. [25] J. Canosa, A. Rodriguez, M. Iglesias, B. Orge, J. Tojo, The Journal of Chemical Thermodynamics 29 (1997) 907–920. [26] M. Iglesias, B. Orge, J.M. Canosa, A. Rodriguez, M. Dominguez, M.M. Pineiro, J. Tojo, Fluid Phase Equilibria 147 (1998) 285–300. [27] R. Francesconi, Journal of Chemical & Engineering Data 44 (1999) 44–47. [28] T. Okano, H. Ogawa, S. Murakami, Canadian Journal of Chemistry 66 (1988) 713–717. [29] J. Wisniak, A. Tamir, Journal of Chemical & Engineering Data 20 (1975) 388–391. [30] J. Canosa, A. Rodriguez, B. Orge, M. Iglesias, J. Tojo, Journal of Chemical & Engineering Data 42 (1997) 1121–1125. [31] A.G. Gilani, N. Paktinat, M. Moghadam, The Journal of Chemical Thermodynamics 43 (2011) 569–575. [32] A.A. Maryott, E.R. Smith, Tables of dielectric constants of pure liquids, NBS, Circular 514, Washington, D. C., 1951; from: Marcus, Y, The Properties of Solvents, John Wiley & Sons Ltd., New York, 1998. [33] F. Buckley, A.M. Maryott, Tables of dielectric dispersion data for pure liquids and dilute solutions, NBS, Circular 589, Washington, D. C., 1958; from: Marcus, Y, The Properties of Solvents, John Wiley & Sons Ltd., New York, 1998. [34] M. Iglesias, B. Orge, J. Tojo, Fluid Phase Equilibria 126 (1996) 203–223. [35] J. Polak, S. Murakami, V.T. Lam, H.D. Pflug, G.C. Benson, Canadian Journal of Chemistry 48 (1970) 2457–2465.