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Acta Phys. -Chim. Sin.  2018, Vol. 34 Issue (2): 194-200    DOI: 10.3866/PKU.WHXB201707262
ARTICLE     
Measurement of Vapor Pressure and Vaporization Enthalpy for Ionic Liquids 1-Hexyl-3-methylimidazolium Threonine Salt[C6mim][Thr]by Isothermogravimetric Analysis
Jing TONG*(),Ye QU,Liqiang JING,Lu LIU,Chunhui LIU
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Abstract  

The amino acid ionic liquid (AAIL) 1-hexyl-3-methylimidazolium threonine salt, [C6mim][Thr], was prepared by the neutralization method and its structure was confirmed by 1H and 13C NMR spectroscopy. Using benzoic acid as the reference material, the vapor pressure and evaporation enthalpy ΔglHm? (Tav) of [C6mim][Thr] were determined by isothermogravimetric analysis at the average temperature (Tav = 438.15 K) and DglHm? (Tav)was found to be (128.5 ± 6.0) kJ·mol-1. Using Verevkin's method, the difference between the heat capacities of the vapor and liquid phases, ΔglCpm?, was calculated to be -70.8 J·K-1·mol-1. Subsequently, the enthalpy of vaporization for AAIL [C6mim][Thr] at different temperatures was determined based on the reference enthalpy of vaporization at 298.15 K, ΔglHm? (298.15 K) = 138.4 kJ·mol-1. This value is 1.6 kJ·mol-1 higher than that predicted by our theoretical model and less than the experimental error (±3.0 kJ·mol-1) of the isothermogravimetric method. These results show that our theoretical model for determining the evaporation enthalpy of ILs is reasonable. In terms of the Clausius-Clapeyron equation, the hypothetical normal boiling point, Tb, was estimated to be 522.07 K. Thus, the evaporation entropy, ΔglSm? (T), and the evaporation Gibbs free energy, ΔglGm? (T), of [C6mim][Thr] could be determined for different temperatures. These results showed that DglGm? (T) decreases as the temperature increases, the evaporation entropy increases with increaseing temperature. Furthermore, the latter is the driving force in the evaporation process of the AAIL [C6mim][Thr].



Key wordsIonic liquid      Isothermogravimetrical analysis      Enthalpy of vaporization      Vapor pressure      Threonine     
Received: 16 June 2017      Published: 26 July 2017
MSC2000:  O642  
Fund:  the National Natural Science Foundation of China(21273003)
Corresponding Authors: Jing TONG     E-mail: tongjinglnu@sina.com
Cite this article:

Jing TONG,Ye QU,Liqiang JING,Lu LIU,Chunhui LIU. Measurement of Vapor Pressure and Vaporization Enthalpy for Ionic Liquids 1-Hexyl-3-methylimidazolium Threonine Salt[C6mim][Thr]by Isothermogravimetric Analysis. Acta Phys. -Chim. Sin., 2018, 34(2): 194-200.

URL:

http://www.whxb.pku.edu.cn/10.3866/PKU.WHXB201707262     OR     http://www.whxb.pku.edu.cn/Y2018/V34/I2/194

Material Source Method of purification Purity (x)
N-methylimidazole ACROS Reduced pressure distillation 0.998
DL-threonine National Pharmaceutical Group Chemical Recrystallization 0.999
1-Bromohexane National Pharmaceutical Group Chemical Distillation 0.996
Ethyl acetate National Pharmaceutical Group Chemical Distillation 0.99
Acetonitrile National Pharmaceutical Group Chemical Distillation 0.99
[C6mim][Thr] Synthesized Vacuum drying 0.99
Deionized water Self-made Quartz second boiling high pure water distiller
Benzoic acid National Institute of Metrology, China 0.999
Table 1 Source and purity of the materials.
Fig 1 Plots of (m0 -m) vs (t -t0) for IL [C6mim][Thr] and benzoic acid. (a) for IL [C6mim][Thr], x: (t -t0)/s; y: 106 (m0 -m)/kg. ■ 413.15 K: y = -7.77 × 10-10 + 1.15 × 10-10 x, r2 = 0.99449, standard deviation(SD) = 2.97 × 10-9; ● 423.15 K: y = -3.88 × 10-7 + 2.55 × 10-10 x, r2 = 0.99998, SD = 4.67 × 10-10; ▲ 433.15 K: y = -1.25 × 10-6 + 5.52 × 10-10 x, r2 = 0.99958, SD = 3.94 × 10-9; ▼ 443.15 K: y = -1.08 × 10-9 + 1.50 × 10-9 x, r2 = 0.99992, SD = 3.54 × 10-9; ◆453.15 K: y = -2.41 × 10-10 + 2.96 × 10-9 x, r2 = 0.99992, SD = 5.38 × 10-9; ? 463.15 K: y = 4.08 × 10-9 + 5.54 × 10-9 x, r2 = 0.99994, SD = 4.09 × 10-9. (b) for benzoic acid, x: (t -t0)/s; y: 107 (m0 -m)/kg. ■ 353.15K: y = -1.71 × 10-9 + 5.78 × 10-11 x, r2 = 0.99962, SD = 5.08 × 10-10; ●358.15K: y = -2.20×10-9 + 1.06 × 10-11 x, r2 = 0.99998, SD = 5.78 × 10-10; ▲363.15K: y = -5.97 × 10-9 + 1.70 × 10-10 x, r2 = 0.99950, SD = 1.34 × 10-9; ▼368.15K: y = -7.18 × 10-9 + 2.60 × 10-10 x, r2 = 0.99926, SD =1.85 × 10-9; ◆373.15K: y = -8.91 × 10-9 + 3.87 × 10-10 x, r2 = 0.99914, SD = 2.41 × 10-9; ? 378.15K: y = -1.09×10-8 +5.68×10-10 x, r2 = 0.99914, SD = 3.04 × 10-9; u 383.15K: y = -1.51 × 10-8 + 8.29 × 10-10 x, r2 = 0.99966, SD = 3.94 × 10-9.
Benzoic acid
T/K 1010(-dm/dt)/(kg·s-1) r2 (T/M)1/2/(K1/2·mol1/2·kg-1/2) p/Pa a 1010υ 10-10k
353.15 0.577 0.9996 53.78 51.69 31.02 1.667
358.15 1.060 0.9998 54.16 70.02 57.41 1.220
363.15 1.693 0.9993 54.53 94.04 92.31 1.019
368.15 2.576 0.9990 54.91 125.3 141.4 0.886
373.15 3.841 0.9988 55.28 165.7 212.3 0.780
378.15 5.625 0.9988 55.65 217.5 313.0 0.695
383.15 8.217 0.9990 56.01 283.4 460.2 0.616
[C6mim][Thr]
T/K 1010(-dm/dt)/(kg·s-1) r2 (T/M)1/2/(K1/2·mol1/2·kg-1/2) p/Pa b 1010υ ln[T1/2·(-dm/dt)/(K?kg·s-1)]
413.15 1.147 0.9999 39.02 44.02 4.477 -19.88
423.15 2.545 0.9999 39.49 98.81 10.05 -19.07
433.15 5.510 0.9999 39.95 216.4 22.01 -18.28
443.15 14.99 0.9998 40.41 595.6 60.58 -17.27
453.15 29.63 0.9999 40.86 1190 121.1 -16.58
463.15 56.52 0.9999 41.31 2295 233.5 -15.92
Table 2 Values of vapor pressure(p), -dm/dt, ln[T1/2·(-dm/dt)], and ν for AAIL [C6mim][Thr] at 413.15–463.15 K and for benzoic acid at 343.15–383.15 K.
Fig 2 Plot of ln ν vs 1/T for ILC6mim][Thr]. y = 18.18-1.548 × 104x, r2 = 0.998, SD = 0.08429. x: 1/T; y: ln ν.
T/K ΔglHm?(T)/(kJ?mol-1) ΔglSm?(T)/(J?K-1?mol-1) TΔglSm?(T)/(kJ?mol-1) ΔglGm?(T)/(kJ?mol-1) p(T)/Pa
298.15 138.4 274.4 81.82 56.58 4.045 × 10-6
320.15 136.8 269.4 86.25 50.60 2.352 × 10-4
340.15 135.4 265.1 90.18 45.26 5.756 × 10-3
360.15 134.0 261.1 94.02 40.00 9.522 × 10-2
380.15 132.6 257.2 97.79 34.81 1.133
400.15 131.2 253.6 101.5 29.71 10.19
420.15 129.8 250.2 105.1 24.67 72.05
440.15 128.4 246.9 108.7 19.70 4.141 × 102
460.15 126.9 243.7 112.2 14.79 1.987 × 103
480.15 125.5 240.7 115.6 9.948 8.144 × 103
500.15 124.1 237.8 118.9 5.163 2.905 × 104
522.07 122.6 234.8 122.6 0 1.013 × 105
Table 3 ΔglHm?(T), ΔglSm?(T), TΔglSm?(T), ΔglGm?(T) and vapor pressure of [C6mim][Thr] during the evaporation process at 298.15–500.15 K and at T = 522 K.
Fig 3 Plots of ΔglHm?(T), TΔglSm?(T), ΔglGm?(T) and p(T) vs T for [C6mim][Thr]. y = 159.44 ? 0.07061 x; r2 = 0.99996, SD = 0.02949;
x: T, y: ΔglHm?(T);
y = 28.323 + 0.18181 x; r2 = 0.99908, SD = 0.42178; x: T, y: TΔglSm?(T);
y = 131.16 ? 0.25249 x; r2 = 0.99954, SD = 0.41492; x: T, y: ΔglGm?(T);
x: T, ? y: p(T)
1 Zhang S. J. ; Liu X. M. Ionic Liquid: From Basic Research to Industrial Applications Science Press: Beijing, 2006.
1 张锁江; 吕兴梅. 离子液体:从基础研究到工业应用, 北京: 科学出版社, 2006.
2 Armand M. ; Endres F. ; MacFarlane D. R. ; Ohno H. ; Scrosati B. Nat. Mater. 2009, 8, 621.
3 Bu X. X. ; Fan B. H. ; Wei J. ; Xing N. N. ; Ma X. X. ; Guan W. Acta Phys. -Chim. Sin. 2016, 32, 267.
3 卜晓雪; 樊本汉; 魏杰; 邢楠楠; 马晓雪; 关伟.物理化学学报. 物理化学学报, 2016, 32, 267.
4 Tao G. H. ; He L. ; Liu W. S. ; Xu L. ; Xiong W. ; Wang T. ; Kou Y. Green Chem. 2006, 8, 639.
5 Fukumoto K. ; Yoshizawa M. ; Ohno H. J. Am. Chem. Soc. 2005, 127, 2398.
6 Zhang S. ; Wang J. ; Lu X. ; Zhou Q. Structures and Interactions of Ionic Liquids Springer: Heidelberg, 2014.
7 Fang D. W. ; Tong J. ; Guan W. ; Wang H. ; Yang J. Z. J. Phys. Chem. B 2010, 114, 13808.
8 Tong J. ; Song B. ; Wang C. X. ; Li L. ; Guan W. ; Fang D. W. ; Yang J. Z. Ind. Eng. Chem. Res. 2011, 50, 2418.
9 Earle M. J. ; Esperanc J. M. S. S. ; Gilea M. A. ; Lopes J. N. C. ; Rebelo L. P. N. ; Magee J. W. ; Seddon K. R. ; Widegren J. A. Nature 2006, 439, 831.
10 Deyko A. ; Lovelock K. R. ; Corfield J. A. ; Taylor A. W. ; Gooden P. N. ; Villar-Garcia I. J. ; Licence P. ; Jones R. G. ; Krasovskiy V. G. ; Chernikova E. A. ; et al Phys. Chem. Chem. Phys. 2009, 11, 8544.
11 Esperanc J. M. S. S. ; Lopes J. N. C. ; Tariq M. ; Santos L. M. N. B. F. ; Magee J. W. ; Rebelo L. P. N. J. Chem. Eng. Data 2010, 55, 3.
12 Zaitsau D. H. ; Kabo G. J. ; Strechan A. A. ; Paulechka Y. U. ; Tschersich A. ; Verevkin S. P. ; Heintz A. J. Chem. Phys. A 2006, 110, 7303.
13 Luo H. ; Baker G. A. ; Dai S. J. Chem. Phys. B 2008, 112, 10077.
14 Heym F. ; Etzold B. J. M. ; Kern C. ; Jess A. Green Chem. 2011, 13, 1453.
15 Verevkin S. P. ; Ralys R. V. ; Zaitsau D. H. ; Emel'yanenko V. N. ; Schick C. Thermochim. Acta 2012, 538, 55.
16 Tong J. ; Yang H. X. ; Liu R. J. ; Li C. ; Xia L. X. ; Yang J. Z J. Phys. Chem. B 2014, 118, 12972.
17 Hong M. ; Liu R. J. ; Yang H. X. ; Guan W. ; Tong J. ; Yang J. Z. J. Chem. Thermodyn. 2014, 70, 214.
18 Zaitsau D. H. ; Kabo G. J. ; Strechan A. A. ; Paulechka Y. U. ; Tschersich A. ; Verevkin S. P. ; Heintz A. J. Chem. Phys. A 2006, 110, 7303.
19 Tong J. ; Chen T. F. ; Zhang D. ; Wang L. F. ; Tong J. ; Yang J. Z. Acta Phys. -Chim. Sin. 2016, 32, 1161.
19 佟静; 陈滕飞; 张朵; 王林富; 佟健; 杨家振. 物理化学学报, 2016, 32, 1161.
20 Li C. ; Yang H. X. ; Liu R. J. ; Yang Q. ; Tong J. ; Yang J. Z. Acta Phys. -Chim. Sin. 2015, 31, 11.
20 李驰; 杨宏旭; 刘入境; 杨奇; 佟静; 杨家振. 物理化学学报, 2015, 31, 11.
21 Stewart, L. N. In Proceedings of the Third Toronto Symposium on Thermal Analysis; McAdie, H. G. Ed.; Chemical Institute of Canada: Toronto, 1969; p. 205.
22 Hinks D. ; Rafiq M. I. ; Price D. M. ; Montero G. A. ; Smith B. A. Color Technol. 2003, 119, 84.
23 Price D. M. Thermochim. Acta 2001, 253, 367.
24 Verevkin S. P. ; Zaitsau D. H. ; Emel'yanenko V. N. ; Yermalayeu A. V. J. Phys. Chem. B 2013, 117, 6473.
25 Zaitsau D. H. ; Yernalayeu A. V. ; Emel'yanenko V. N. ; Verevkin S. P. ; Welz-Biermann U. ; Schubert T. Sci. China Chem. 2012, 55, 1526.
26 Paulechka Y. U. ; Zaitsau D. H. ; Kabo G. J. J. Mol. Liq. 2004, 115, 105.
27 Zhang D. ; Qu Y. ; Gong Y. Y. ; Tong J. ; Fang D. W. ; Tong J. J. Chem. Thermodyn. Submitted.
28 Tong J. ; Liu L. ; Li H. ; Guan W. ; Chen X. J. Chem. Thermodyn. 2017, 112, 293.
29 Archer D. G. ; Widegren J. A. ; Kirklin D. R. ; Magee J. W. J. Chem. Eng. Data 2005, 50, 1484.
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