Excess Molar Enthalpies of Binary Mixtures Containing 1-Methyl-3

Article pubs.acs.org/jced

Excess Molar Enthalpies of Binary Mixtures Containing 1‑Methyl-3octyl-imidazolium Tetrafluoroborate and Alcohols at T = 298.15 K Dashuang Fan,† Handi Yin,† Dongxing Cai,† Zhencun Cui,† and Weiguo Shen*,†,‡ †

Department of Chemistry, Lanzhou University, Lanzhou 730000, China School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China

‡

ABSTRACT: An isothermal titration calorimeter was used to measure the excess molar enthalpies (HE) at T = 298.15 K for five binary systems: 1-methyl3-octyl-imidazolium tetrafluoroborate (OmimBF4) + alcohols (ethanol, 1propanol, 2-propanol, 1-butanol, and 1-pentanol). The values of HE were found to be all positive for the five systems and were fitted with the Redlich−Kister polynomial and the UNIQUAC mode. The magnitude order of HE for the five systems was explained by the balance between the magnitude orders of enthalpies of the alcohol/alcohol and the alcohol/OmimBF4 interactions.

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INTRODUCTION Knowledge of excess molar enthalpies HE for mixtures is valuable and fundamental information in designing and developing industrial processes and elucidating microscopic structures of the solutions and interactions among the components.1,2 Measurements of HE have been extended to the liquid mixtures containing ILs to investigate the molecular interactions between the components in the IL mixtures as well as to test and to develop new theories and models that are able to describe the behavior of IL mixtures.2,3 The mixtures of 1-methyl-3-octyl-imidazolium tetrafluoroborate (OmimBF4) with alcohols have been studied,4−6 and attention has been paid to the phase equilibrium, density, viscosity, refractive index, activity, osmotic coefficients, speed of sound, etc. However the enthalpy properties of mixing for those systems have not yet been found to be reported, which was required to understand the like-pair and unlike-pair interactions in the mixtures and their dependences on the length of the alcohol molecule and the position of the hydroxyl (OH) group in the alcohol molecule. In this work, excess molar enthalpies of five (OmimBF4 + alcohols) systems with different compositions are determined at T = 298.15 K by isothermal titration calorimetry (ITC), and fitted by the Redlich−Kister polynomial and the UNIQUAC mode.7,8 The effects of the chain length of the alcohol and the position of the OH group in the alcohol on HE and the molecular interactions between the components in the IL mixtures are discussed.

1-pentanol were dried over 0.4 nm molecular sieves before use. The water concentrations of OmimBF4 and alcohols were checked by the Karl Fischer titration using a Metrohm 831 KF Coulometer and found to be less than 200 ppm. Table 1 lists the suppliers and purities of the chemicals used in this work, and Figure 1 shows the chemical structure of OmimBF4. Table 1. Suppliers and Purities of the Chemicals chemical name

Chengjie Chemical

0.99

ethanol

Tianjin Chem. Ltd. Co. Alfa Aesar Alfa Aesar Alfa Aesar Alfa Aesar

dry and store method

water content (ppm)

0.997

dried under an oil-pump vacuum at 330 K for 2 weeks and then stored in a desiccator over P2O5 0.4 nm molecular sieves

140

0.999 0.999 0.999 0.999

0.4 0.4 0.4 0.4

110 120 116 105

nm nm nm nm

molecular molecular molecular molecular

sieves sieves sieves sieves

164

1-Methyl-3-octyl-imidazolium tetrafluoroborate.

Calorimetric Measurement. Excess molar enthalpies were determined by an isothermal titration microcalorimeter (TAM 2277-201, Thermometric, Sweden) at 298.15 K. The apparatus and titration procedure have been described in detail previously.9−11 The IL of 1.25 mL was placed in a 4 mL ampule and a Hamilton syringe was used to continuously inject

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EXPERIMENTAL SECTION Chemicals. The ionic liquid OmimBF4 was purified by high vacuum evaporation at 330 K for several days to remove the traces of water. Ethanol, 1-propanol, 2-propanol, 1-butanol, and © 2014 American Chemical Society

OmimBF4a

1-propanol 2-propanol 1-butanol 1-pentanol a

supplier

purity, mass fraction

Received: August 2, 2013 Accepted: February 12, 2014 Published: February 20, 2014 678

dx.doi.org/10.1021/je400709f | J. Chem. Eng. Data 2014, 59, 678−683

Journal of Chemical & Engineering Data

Article

Figure 1. Chemical structure of OmimBF4.

the alcohol into the ampule. Because the viscosity of OmimBF4 is very high, it could not be used to titrate alcohol loaded in the ampule through the Hamilton syringe; thus the measurements were limited in a concentration region with the mole fractions x1 of OmimBF4 varying from 0.12 to 0.98 during a process of continuous addition of about 2.4 mL of alcohol into the ampule. The stirring speed in the ampule and the titration speed of the syringe were set at 120 rpm and 1.0 μL·s−1, respectively. Integration of the jth heat flow peak yields the amount of the heat of mixing during the jth injection (δqi).The value of the excess molar enthalpy HEi at the concentration after the i-th injection may be readily calculated by:2,12

Figure 2. Experimental excess molar enthalpies (HE) and comparison with literature data for the test binary system: cyclohexane (1) with benzene (2). Symbols: □, ref 15; ○, ref 16; Δ, ref 17; ▽, ref 18; ◀, this work.

i

HiE

=

∑ j = 1 δqi

agreement better than 1 % over the entire range of mole fraction of cyclohexane. Because the uncertainties caused by vaporization or condensation are more significant for volatile liquids and the two components of the test mixture are more volatile than the liquids studied in this work, the uncertainties in measurements of HE for IL mixtures were believed to be within 1 % of the values. This precision was also confirmed by repeating the measurements of HE for (OmimBF4 + ethanol) and (OmimBF4 + 1-propanol), and the agreements were about 1 %, which are shown in Figure 3a,b.

i

n1 + ∑ j = 1 Δn2, j

(1)

where n1 is the number of moles of IL in the ampule and Δn2,j is the number of moles of alcohol injected during the jth titration. Mole fractions of OmimBF4 x1 were determined from the volumes of OmimBF4 in the ampule and the alcohol added from the syringe, and the densities of two components listed in Table 2.13,14 The uncertainty in x1 increased in the successive

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Table 2. Molecular Weight, MW, the Density, ρ, at 298.15 K, and the Structural Parameters, q, of Pure Components Used in Fitting with the Redlich−Kister Equation and the UNIQUAC Equation compound OmimBF4 ethanol 1-propanol 2-propanol 1-butanol 1-pentanol a

MW

ρ

g·mol−1

g·mL−1

282.13 46.07 60.10 60.10 74.12 88.15

a

1.10368 0.78540b 0.79991b 0.78093b 0.80596b 0.81097b

RESULTS AND DISCUSSION The experimental HE data are reported in Table 3 and shown in Figure 3a−e. The values of HE for the five systems are all positive. The maximum values of HE are 2604 J·mol−1 at x1 = 0.404 for (OmimBF4 + ethanol), 2659 J·mol−1 at x1 = 0.425 for (OmimBF4 + 1-propanol), 2862 J·mol−1 at x1 = 0.407 for (OmimBF4 + 2-propanol), 2557 J·mol−1 at x1 = 0.429 for (OmimBF4 + 1-butanol), and 2542 J·mol−1 at x1 = 0.471 for (OmimBF4 + 1-pentanol). The order of these maximum values of HE is 2-propanol > 1-propanol > ethanol > 1-butanol > 1pentanol. The experimental HE data were fitted to the Redlich−Kister equation:

q 8.519c 2.588c 3.128c 3.124c 3.668c 4.208c

From ref 13. bFrom ref 14. cFrom ref 6.

m

HE = x1(1 − x1) ∑ Ak (2x1 − 1)k k=0

dilution process due to accumulation of the uncertainties, which was estimated to be less than 0.001 for almost all experimental points except for a few most diluted IL concentrations. Measurement of the heat of mixing with ITC has the disadvantage that a vapor space exists in the calorimetric vessel. It causes uncertainties due to vaporization or condensation during the titration process and are difficult to be estimated. Therefore before investigation of IL mixtures, the calorimeter and the experiment method were checked by measurement of HE for the test mixture of cyclohexane + benzene, which is compared with the literature data15−18 in Figure 2, indicating an

(2)

where the parameters Ak were determined by the least-squares method, which are listed in Table 4 with the standard deviations δ of fitting defined by δ=

1 N−m

N E E ∑ (Hcal, i − Hexp , i) i=1

(3)

In eq 3, N and m are the number of data points and the number of coefficients Ak; HEcal,i and HEexp,i are the calculated and experimental values of HE, respectively. The values of HEcal,i and HEexp,iare compared in Figure 3a−e. 679



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Figure 3. Excess molar enthalpies (HE) for the system of (OmimBF4 + alcohol) at 298.15 K, (a) ethanol, (b) 1-propanol, (c) 2-propanol, (d) 1butanol, and (e) 1-pentanol. Symbols are experimental data: ▲, run 1; Δ, run 2; , calculated values by the Redlich−Kister equation; and ---, calculated values by the UNIQUAC model.

The excess molar enthalpy of a binary mixture (IL + alcohol) can be visualized as the sum of two positive contributions coming from the breaking of cohesion forces in pure ionic liquid and pure alcohol during the mixing process and one

negative contribution arising from the newly established unlikepair interactions.2,19 The positive values of HE for the all five (OmimBF4 + alcohol) systems indicate that the mixing processes are endothermic, and alcohols and OmimBF4 can 680



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Table 3. Excess Molar Enthalpy HE of Five Binary Systems of (OmimBF4 + alcohol) at T = 298.15 K and p = 0.1 MPa for Various Mole Fractions of OmimBF4 x1a HE x1

J·mol

HE −1

0.966 0.935 0.906 0.878 0.852 0.828 0.805 0.783 0.762 0.743 0.724 0.706 0.689 0.673 0.658 0.643 0.629 0.616 0.603 0.591

233 442 629 806 963 1112 1244 1368 1481 1584 1679 1766 1846 1918 1986 2046 2104 2154 2202 2245

0.974 0.949 0.925 0.902 0.881 0.860 0.841 0.822 0.804 0.787 0.771 0.755 0.740 0.725 0.711 0.698 0.685 0.672 0.660 0.649 0.638 0.627

199 383 547 705 847 985 1110 1227 1336 1437 1532 1620 1704 1779 1853 1918 1983 2040 2097 2146 2195 2239

0.974 0.950 0.927 0.904 0.883 0.863 0.844 0.825 0.808 0.791 0.775

201 382 559 717 870 1008 1141 1260 1376 1482 1582

x1

HE −1

J·mol

x1

HE −1

J·mol

OmimBF4 (1) + Ethanol (2) 0.579 2286 0.334 2557 0.567 2321 0.324 2542 0.556 2356 0.315 2524 0.546 2385 0.307 2502 0.536 2414 0.299 2479 0.526 2438 0.291 2453 0.517 2461 0.284 2424 0.507 2482 0.277 2394 0.499 2499 0.271 2363 0.490 2516 0.264 2331 0.470 2545 0.259 2300 0.452 2569 0.253 2268 0.435 2591 0.247 2235 0.419 2599 0.242 2203 0.404 2604 0.237 2171 0.390 2603 0.230 2134 0.377 2599 0.222 2099 0.365 2591 0.216 2065 0.354 2581 0.209 2034 0.344 2570 0.204 2004 OmimBF4 (1) + 1-Propanol (2) 0.616 2282 0.353 2595 0.606 2321 0.345 2568 0.596 2357 0.337 2539 0.587 2391 0.329 2511 0.578 2422 0.322 2479 0.569 2451 0.315 2449 0.560 2477 0.309 2416 0.552 2502 0.302 2383 0.532 2551 0.296 2351 0.513 2582 0.290 2318 0.496 2607 0.285 2285 0.480 2628 0.276 2236 0.465 2643 0.268 2187 0.451 2653 0.261 2139 0.437 2658 0.253 2093 0.425 2659 0.247 2048 0.413 2657 0.240 2005 0.401 2658 0.234 1964 0.391 2653 0.228 1925 0.381 2643 0.223 1888 0.371 2630 0.217 1854 0.362 2612 0.212 1818 OmimBF4 (1) + 2-Propanol (2) 0.622 2374 0.359 2784 0.612 2418 0.350 2753 0.602 2455 0.342 2719 0.593 2493 0.335 2684 0.584 2526 0.327 2647 0.575 2559 0.320 2610 0.566 2588 0.314 2571 0.558 2615 0.307 2534 0.538 2670 0.301 2496 0.519 2718 0.295 2458 0.502 2757 0.290 2419

x1

HE −1

x1

J·mol

0.198 0.193 0.188 0.183 0.178 0.174 0.170 0.166 0.162 0.159 0.155 0.152 0.149 0.146 0.143 0.140 0.137 0.135

1975 1948 1923 1898 1874 1850 1827 1804 1781 1760 1738 1718 1698 1677 1657 1636 1617 1597

0.208 0.203 0.199 0.194 0.190 0.187 0.183 0.179 0.176 0.173 0.169 0.166 0.163 0.159 0.156 0.152 0.149 0.146 0.144 0.141 0.138 0.136

1784 1752 1721 1691 1663 1637 1612 1588 1564 1541 1518 1497 1471 1445 1419 1394 1370 1347 1325 1303 1282 1263

0.212 0.207 0.202 0.198 0.194 0.190 0.186 0.183 0.179 0.176 0.173

1891 1863 1837 1812 1789 1766 1744 1722 1700 1680 1660

HE −1

J·mol

0.759 0.744 0.730 0.716 0.703 0.690 0.678 0.666 0.654 0.643 0.632

1676 1762 1844 1919 1991 2056 2119 2176 2232 2281 2331

0.978 0.958 0.938 0.919 0.900 0.883 0.866 0.850 0.834 0.819 0.804 0.790 0.777 0.764 0.751 0.739 0.727 0.715

172 333 477 624 754 870 968 1061 1149 1232 1311 1385 1455 1520 1582 1640 1695 1745

0.982 0.964 0.947 0.930 0.914 0.899 0.884 0.870 0.856 0.842 0.829 0.817 0.804 0.792 0.781 0.770 0.759 0.748 0.738 0.728

134 262 388 503 618 722 825 920 1013 1099 1182 1259 1334 1405 1472 1537 1597 1655 1709 1763

x1

J·mol

HE −1

x1

HE −1

J·mol

OmimBF4 (1) + 2-Propanol (2) 0.486 2788 0.281 2364 0.471 2813 0.273 2310 0.456 2832 0.265 2259 0.443 2845 0.258 2209 0.430 2853 0.251 2139 0.418 2858 0.244 2099 0.407 2862 0.238 2063 0.396 2858 0.232 2026 0.386 2849 0.227 1988 0.377 2834 0.221 1954 0.367 2811 0.216 1922 OmimBF4 (1) + 1-Butanol (2) 0.704 1794 0.451 2555 0.693 1855 0.440 2556 0.683 1903 0.429 2557 0.673 1943 0.419 2545 0.663 1982 0.410 2531 0.653 2018 0.400 2505 0.644 2052 0.392 2480 0.622 2138 0.383 2450 0.601 2220 0.371 2416 0.582 2282 0.359 2368 0.563 2344 0.348 2316 0.546 2388 0.337 2264 0.530 2433 0.328 2211 0.515 2463 0.318 2159 0.501 2493 0.309 2109 0.487 2512 0.301 2059 0.474 2533 0.293 2010 0.462 2542 0.286 1963 OmimBF4 (1) + 1-Pentanol (2) 0.718 1811 0.481 2537 0.708 1859 0.471 2542 0.699 1903 0.460 2539 0.690 1946 0.451 2529 0.681 1986 0.441 2512 0.673 2024 0.432 2489 0.664 2060 0.424 2461 0.656 2095 0.415 2432 0.648 2127 0.407 2402 0.640 2158 0.400 2371 0.622 2225 0.392 2339 0.604 2283 0.385 2308 0.587 2333 0.378 2278 0.572 2378 0.372 2247 0.557 2418 0.365 2217 0.542 2450 0.356 2175 0.529 2476 0.346 2132 0.516 2498 0.338 2091 0.504 2514 0.329 2052 0.492 2527 0.321 2013

x1

J·mol−1

0.170 0.165 0.162 0.158 0.154 0.151 0.148 0.144 0.142 0.139

1639 1613 1587 1559 1532 1506 1480 1456 1432 1410

0.279 0.272 0.266 0.259 0.254 0.248 0.243 0.238 0.233 0.228 0.223 0.219 0.214 0.209 0.204 0.200 0.195 0.191

1929 1895 1865 1833 1803 1777 1752 1727 1704 1681 1659 1638 1606 1575 1544 1515 1487 1460

0.314 0.306 0.300 0.293 0.287 0.281 0.275 0.269 0.264 0.259 0.254 0.249 0.244 0.240 0.234 0.229 0.223 0.218 0.213

1976 1941 1913 1883 1852 1822 1795 1768 1742 1716 1692 1667 1643 1624 1591 1559 1528 1497 1464

a

Standard uncertainties of T, HE, and x1 are u(T) = 0.01 K, u(HE) = 1 % HE, u(x1) = ± 0.001.

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region, the positive contribution to HE from disassociation of hydrogen bonds between the ethanol molecules dominates the magnitude order of HE of the five alcohols; while at the higher value of x1, i.e., in the OmimBF4 rich region, the negative contribution to HE from the cross-association between OmimBF4 and ethanol dominates the magnitude order of HE for the three alcohols, the shorter ethanol molecule has more negative contribution to HE, thus the lower total positive value of HE than 1-propanol and 2-propanol in the OmimBF4 rich region. HE can also be expressed by the UNIQUAC equation7,8

Table 4. Parameters of Redlich−Kister Equation and the Standard Deviation δ of Fitting for Five Binary Systems of (OmimBF4 + Alcohol) at T = 298.15 Ka A0 alcohol ethanol 1-propanol 2-propanol 1-butanol 1-pentanol a

A1 −1

J·mol

9992 10496 11114 9937 9932

A2 −1

J·mol

−3912 −3229 −3435 −2453 −655

J·mol

δ

A3 −1

822 −2172 −2458 −3412 −4430

−1

J·mol

−35 3127 3034 4831 2434

J·mol−1 23 20 41 35 32

⎞ ⎛ ⎞ ⎛ θ2 θ1 HE = q1x1⎜ ⎟τ12Δu12 ⎟τ21Δu 21 + q2x 2⎜ ⎝ θ2 + θ1τ12 ⎠ ⎝ θ1 + θ2τ21 ⎠

Standard uncertainties of T is u(T) = 0.01 K.

not easily break their like-pair interactions (or associations) to interact with each other or to form cross-association complexes.2,20,21 This phenomenon agrees well with other binary systems of IL and alcohol.2,22,23 As compared in Figure 4, the magnitude of HE for all the binary systems we studied follows the orders: (a) 1-propanol >

(4)

with τ21 = exp( −Δu 21/RT );

θ1 =

x1q1 x1q1 + x 2q2

;

τ12 = exp( −Δu12 /RT )

θ2 =

x 2q2 x1q1 + x 2q2

where qi is the structural parameter of each of the pure components (the subscript i = 1 or 2 refers to the OmimBF4 or the alcohol) and their values were taken from the literature6 and are listed in Table 2; Δu12 and Δu21 are the interaction energy parameters, Δu12 represents the energy differences between the alcohol/OmimBF4 interaction and alcohol/alcohol interaction, and Δu21 represents that between the alcohol/ OmimBF4 interaction and OmimBF4/OmimBF4 interaction. According to eq 4, in the alcohol rich region, the second term in the equation dominates the HE value because of the small value of x1; while in the OmimBF4 rich region the first term is dominant. Thus the accordance of the magnitude orders of Δu12 and Δu21 with the orders of HE observed experimentally in the alcohol rich and OmimBF4 rich regions, respectively, should be expected. The values of the parameters Δu12 and Δu21 were obtained by a nonlinear least-squares fitting of the HE data with eq 4 and together with δ are listed in Table 5. The fitting results with the

Figure 4. Comparison of excess molar enthalpies (HE) for five binary systems of (OmimBF4 + alcohol) at 298.15 K. Symbols: ■, ethanol; □, 1-propanol; ○, 2-propanol; ◊, 1-butanol; ●, 1-pentanol.

Table 5. Parameters of UNIQUAC Equation and the Standard Deviation, δ, for Five Binary Systems of (OmimBF4 + Alcohol) at 298.15 K

1-butanol > 1-pentanol in the whole composition range; (b) 2propanol > 1-propanol in the whole composition range; (c) ethanol > other alcohols at the low composition range of OmimBF4, while ethanol < 1-propanol < 2-propanol at the high composition range of OmimBF4. The magnitude order (a) indicates that HE decreases with the increase of the carbon chain of the alcohols, which may be attributed to the fact that the enthalpies for breaking of cohesion forces in pure alcohols decrease with the increase of the length of the alcohol molecules and dominate this magnitude order. The infrared spectroscopy evidenced that the self-association of the alcohol tends to decrease with the increase of the molecular weight of the alcohol,24 which is in accordance with the observation in our HE measurement. In addition, the magnitude order (b) may be interpreted by the fact that the interaction between OmimBF4 and alcohol molecules or the possible cross-association between OmimBF4 and alcohols results in the negative contribution to HE,5 and this contribution is possibly more significant to 1-propanol than 2-propanol due to the stronger steric hindrance of 2propanol.25 Finally, the magnitude order (c) may be interpreted by the fact that at a low value of x1, i.e., in the ethanol rich

Δu12 alcohol ethanol 1-propanol 2-propanol 1-butanol 1-pentanol

J·mol

Δu21

−1

2234 2375 2457 2014 1938

δ

−1

J·mol

1172 657 804 428 291

J·mol−1 65 108 125 110 115

UNIQUAC equation are compared with the experimental results in Figure 3a−e. The standard deviation of fitting the UNIQUAC equation is larger than that of the Redlich−Kister equation, which is not surprising because the numbers of adjusting parameters are 2 for the UNIQUAC equation and 4 for the Redlich−Kister equation. It may be seen in Table 5 that the value of Δu21 follows the magnitude order: ethanol > 2propanol > 1-propanol > 1-butanol > 1-pentanol; while the values of Δu12 follows the order: 2-propanol > 1-propanol > ethanol. It coincides with the experimental observations of the 682



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magnitude orders of HE in the ethanol rich region and the OmimBF4 rich region respectively.

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octylimidazolium Hexafluorophosphate and 1-Methyl-3-octylimidazolium Tetrafluoroborate. J. Chem. Eng. Data 2006, 51, 1161−1167. (14) Kulikov, D.; Verevkin, S. P.; Heintz, A. Enthalpies of vaporization of a series of aliphatic alcohols: Experimental results and values predicted by the ERAS-model. Fluid Phase Equilib. 2001, 192, 187−207. (15) Abello, L. Enthalpies d’excès des systèmes binaires constitués d’hydrocarbures benzéniques et du chloroforme ou du méthylchloroforme. J. Chim. Phys. Phys.-Chim. Biol. 1973, 70, 1355−1359. (16) Cabani, S.; Ceccanti, N. Thermodynamic properties of binary mixtures of cyclohexane with cyclic amines or cyclic ethers at 298.15 K. J. Chem. Thermodyn. 1973, 5, 9−20. (17) Stokes, R. H.; Marsh, K. N.; Tomlins, R. P. An isothermal displacement calorimeter for endothermic enthalpies of mixing. J. Chem. Thermodyn. 1969, 1, 211−221. (18) Gmehling, J. Excess Enthalpies for 1,1,1-Trichloroethane with Alkanes, Ketones, and Esters. J. Chem. Eng. Data 1993, 38, 143−146. (19) Li, S. H.; Yan, W. D. Excess Molar Enthalpies of Acetophenone + (Methanol, + Ethanol, + 1-Propanol, and + 2-Propanol) at Different Temperatures and Pressures. J. Chem. Eng. Data 2008, 53, 551−555. (20) Pires, J.; Timperman, L.; Jacquemin, J.; Balducci, A.; Anouti, M. Density, Conductivity, viscosity, and excess properties of (pyrrolidinium nitrate-based Protic Ionic Liquid + propylene carbonate) binary mixture. J. Chem. Thermodyn. 2013, 59, 10−19. (21) Li, S. Y.; Yan, W. D.; Dong, H. Determination of partial molar excess enthalpies at infinite dilution for the systems four alcohols + (bmim)PF6 at different temperatures by isothermal titration calorimeter. Fluid Phase Equilib. 2007, 261, 444−448. (22) Iglesias-Otero, M. A.; Troncoso, J.; Carballo, E.; Romaní, L. Densities and Excess Enthalpies for Ionic Liquids + Ethanol or + Nitromethane. J. Chem. Eng. Data 2008, 53, 1298−1301. (23) Gu, Z.; Brennecke, J. F. Volume Expansivities and Isothermal Compressibilities of Imidazolium and Pyridinium-Based Ionic Liquids. J. Chem. Eng. Data 2002, 47, 339−345. (24) Franks, F.; Ives, D. J. G. The structural properties of alcoholwater mixtures. Q. Rev. Chem. Soc. 1966, 20, 1−44. (25) Zarei, H.; Parvini, E.; Behroozi, M. Experimental study on the calorimetric data of cyclohexanol with alkanols (C1-C4) and correlation with the Wilson, NRTL and UNIQUAC models at T = 300 K. J. Chem. Thermodyn. 2012, 51, 139−143.

AUTHOR INFORMATION

Corresponding Author

*Phone: +86−21−64250804. Fax: +86−21−64252510. E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (Projects 20973061, 21173080, 21373085, and 21303055).

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REFERENCES

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