| 1. |
- Ahmad, Waqar, et al.
(författare)
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Thermophysical Study of Binary Systems of tert-Amyl Methyl Ether with n-Hexane and m-Xylene
- 2019
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 64:2, s. 459-470
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Tidskriftsartikel (refereegranskat)abstract
- This work presents the experimentally determined density (rho), viscosity (eta), speed of sound (u), and surface tension (sigma) data for tert-amyl methyl ether (TAME) + n-hexane and TAME + m-xylene systems at several temperatures (298.15, 308.15, 318.15, 323.15, and 328.15 K). These experimentally determined thermophysical data are utilized to compute various excess/deviation parameters such as molar volume (V-E), isentropic compressibility (K-s(E)), speed of sound (u(E)), deviation in viscosity (Delta In eta), isobaric thermal expansion coefficient (alpha(E)(P)), and surface tension (sigma(E)). The inspection of parameters response may interpret the existing specific molecular interactions as well as the mixing behavior of solutions. The critical analysis of observed parametric behavior have unveiled the strong and weak molecular interactions in TAME with m-xylene and TAME with n-hexane systems, respectively.
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| 2. |
- ARMENANTE, PM, et al.
(författare)
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Salting--Out Parameters for Organic Acids
- 1982
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 1520-5134 .- 0021-9568. ; 27:2, s. 155-156
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Baird, Zachariah Steven, et al.
(författare)
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Vapor-Liquid Equilibrium of Ionic Liquid 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium Acetate and Its Mixtures with Water
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2405-2421
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Tidskriftsartikel (refereegranskat)abstract
- Ionic liquids have the potential to be used forextracting valuable chemicals from raw materials. These processesoften involve water, and after extraction, the water or otherchemicals must be removed from the ionic liquid, so it can bereused. To help in designing such processes, we present data onthe vapor−liquid equilibrium of the system containing protic ionicliquid 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium acetate,water, acetic acid, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene. Earlier studies have only focused on mixtures of water and anionic liquid with a stoichiometric ratio of the ions. Here, we alsoinvestigated mixtures containing an excess of the acid or basecomponent because in real systems with protic ionic liquids, theamount of acid and base in the mixture can vary. We modeled thedata using both the ePC-SAFT and NRTL models, and we compared the performance of different modeling strategies. We alsoexperimentally determined the vapor composition for a few of the samples, but none of the modeling strategies tested couldaccurately predict the concentration of the acid and base components in the vapor phase.
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| 4. |
- Braun, NO, et al.
(författare)
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Densities and viscosities of mono(ethylene glycol) plus 2-amino-2-methyl-1-propanol plus Water
- 2001
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 1520-5134 .- 0021-9568. ; 46:4, s. 805-808
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Tidskriftsartikel (refereegranskat)abstract
- The densities and viscosities of ternary mixtures of mono(ethylene glycol) (MEG) + 2-amino-2-methyl-1-propanol (AMP) + water have been measured at temperatures of 25 to 40 degreesC. The water content varied in the range 1.4 to 15.6 mol %, and the amine concentration varied from 0 to 11.8 mol %. The excess volumes were calculated from the experimental data and fitted to a simple Redlich-Kister type polynomial relation. The equation of Grunberg and Nissan for the viscosity of liquid mixtures was used to correlate the viscosity data.
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| 5. |
- Brommer, Sandra, et al.
(författare)
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Determination of vapor pressures for organophosphate esters
- 2014
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 59:5, s. 1441-1447
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Tidskriftsartikel (refereegranskat)abstract
- Organophosphate compounds are ubiquitous in the environment and to better understand and predict their environmental transport and fate, well-defined physical-chemical properties are needed. The subcooled liquid-phase vapor pressures at 298.15 K (p298) were determined for 11 chlorinated and nonchlorinated phosphate flame retardants (PFRs) by the capillary gas chromatography retention time method (GC-RT). Values of log (p298/Pa) ranged from -5.22 to -1.32 and enthalpies of vaporization (δ l gH/kJ·mol-1) ranged from 82.0 to 109. Log (p298/Pa) by GC-RT showed good overall agreement with estimates using the Modified Grain Method (EpiSuite) and with the mean of experimental and in silico literature values, whereas values for the chlorinated PFRs appeared to be overestimated. SPARC modeling seriously underestimated p298, especially for the less volatile compounds. The Junge-Pankow adsorption model at 288.15 K predicted that most of the PFRs would be predominantly in the particulate phase in urban air and distributed between the particulate and gaseous phases in background air.
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| 6. |
- Brown, P. L., et al.
(författare)
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Dissociation Constants of alpha-D-Isosaccharinic Acid: "Composite" and "Intrinsic" Values
- 2010
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Ingår i: Journal of Chemical & Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:11, s. 5207-5213
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Tidskriftsartikel (refereegranskat)abstract
- The transformation of alpha-D-isosaccharinic acid into alpha-D-isosaccharino-1,4-lactone proceeds relatively slowly. Consequently, the transformation constant, K-L, has been determined kinetically in 1.0 mol center dot dm(-3) NaClO4 and at 23 degrees C. A previous determination in 0.1 mol center dot dm(-3) NaClO4 and at 23 degrees C has been reinterpreted. The values obtained have been coupled with other data in the literature to demonstrate that the magnitude of the transformation constant is independent of ionic strength, and its value was determined to be log K-L degrees = 0.80 +/- 0.02. Data from the literature for the dissociation of alpha-D-isosaccharinic acid have been re-evaluated to determine both the "intrinsic" and "composite" dissociation constants at zero ionic strength, namely, log K-u degrees = -4.04 +/- 0.06 and log K-c degrees = -4.90 +/- 0.07, respectively. The present data permit a much more thorough understanding of the aqueous chemistry of alpha-D-isosaccharinic acid to be ascertained than has previously been possible.
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| 7. |
- Burman, Åsa Ulrika, 1969, et al.
(författare)
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Vapor-Liquid Equilibrium for Mixtures of Ethylethylenediamine, Ethylenediamine, and Water
- 2013
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Ingår i: Journal of Chemical & Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 58:2, s. 257-263
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Tidskriftsartikel (refereegranskat)abstract
- he temperature and the composition of the vapor and liquid phases at equilibrium were measured at atmospheric pressure and (SO and 20) kPa for the binary mixtures: water (I) and ethylenediamine (2, EDA); water and ethylethylenediamine (3, EtEDA); and EDA and EtEDA. For the ternary mixture of water, EDA, and EtEDA, equilibrium conditions were measured at atmospheric pressure. The vapor pressure of EtEDA was measured in the temperature range from (358 to 402) K, and Antoine parameters were fitted to the data. Parameters for the universal quasichemical (UNIQUAC) equation are estimated from binary data and applied to the ternary mixture. It was shown that the mixture of EDA and EtEDA has a zeotropic pinch close to pure EDA. Furthermore, it was found that the ternary mixture has a saddle point azeotrope at a molar fraction of 0.24 of water, 0.62 of EDA, and 0.14 of EtEDA and a temperature of 392.6 K at atmospheric pressure. Thus, the volatility between EDA and EtEDA is reversed in the water-rich region, and EtEDA is the most volatile component close to the binary azeotrope between water and EDA. This is illustrated by univolatility lines in a ternary diagram.
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| 8. |
- Chen, Yifeng, et al.
(författare)
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Thermodynamic Study for Gas Absorption in Choline-2-pyrrolidine-carboxylic Acid + Polyethylene Glycol
- 2016
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 61:10, s. 3428-3437
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of pure CO2, CH4, and N2 in the mixture of choline-2-pyrrolidine carboxylic acid ([Cho][Pro]) and polyethylene glycol (PEG200) (mass ratio = 1:2) was measured experimentally at temperatures from 308.15 to 338.15 K and pressures up to 28 bar, in which [Cho][Pro] is an ionic liquid and PEG200 is a cosolvent with the purpose to decrease the viscosity. It was found that [Cho][Pro]/PEG200 showed a good selectivity for CO2/CH4 and CO2/N2 separation. The measured experimental data points from this work and others were further used to estimate the thermodynamic properties including the Henry's law constants for the gases in [Cho][Pro]/PEG200, the equilibrium constant for the reaction between CO2 and [Cho][Pro], the CO2 absorption enthalpy in [Cho][Pro]/PEG200, and so forth. The consistent results of the CO2 absorption enthalpy at infinite dilution prove the reliability of the thermodynamic properties obtained in this work. The thermodynamic properties of [Cho][Pro]/PEG200 were further compared with other three typical absorbents, and the absorption enthalpy is nearly half of that for 30 wt % MEA aqueous solution. At the same time, the theoretical amount of absorbents needed for [Cho][Pro]/PEG200 is much lower than that of H2O scrubbing. This shows that [Cho][Pro]/PEG200 is a promising absorbent
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| 9. |
- Cheuk, D., et al.
(författare)
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Solid Forms, Crystal Habits, and Solubility of Danthron
- 2015
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 60:7, s. 2110-2118
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Tidskriftsartikel (refereegranskat)abstract
- The polymorphism, crystal habits, and solubility of 1,8-dihydroxyanthraquinone (danthron) were investigated in acetic acid, acetone, acetonitrile, n-butanol, and toluene. The solubility was determined for the commercially available form (FI) from 293.15 K to 318.15 K. by the gravimetric method. The influence of solvents on crystal habit and polymorphic form has been investigated. Three different crystal habits of danthron were obtained from slow evaporation and cooling experiments. By evaporation, thin squares of FI were obtained from n-butanol and toluene solutions while both FT and fine needles of FIT were obtained from acetone and acetonitrile solutions. In addition, needle-shaped solvate crystals were obtained from acetic acid solutions and the structure of the solvate was solved by single crystal X-ray diffraction. From cooling crystallization experiments, mixtures of FI and FIT were often obtained from various solvents, but FT and FIT possess distinct habits which can be easily distinguished by visual comparison. Slurry conversion experiments have established that FT is the thermodynamically stable polymorph of danthron at ambient conditions. Differntial scanning calorimetry (DSC) and high-temperature powder X-ray diffraction (PXRD) have shown that both FI and FII will transform into a high-temperature form (FIV) around 435 K to 439 K before this form melts at 468.5 K. FI, FIT, and FIV have been characterized by transmission and high-temperature PXRD, scanning electron microscopy, infrared spectrometry, Raman spectrometry, thermogravimetric analysis, and DSC. The solubility of danthron FI in the pure organic solvents of the present work and in the temperature range investigated is below 4.3 % by weight and decreases in the order toluene, acetone, acetonitrile, and n-butanol.
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| 10. |
- Corkery, Robert W., 1967-, et al.
(författare)
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Emulsion inversion in the PIT range: Quantitative phase variations in a two-phase emulsion
- 2010
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:10, s. 4471-4475
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Tidskriftsartikel (refereegranskat)abstract
- The phase-inversion temperature (PIT) phenomenon is for the first time given a quantitative treatment for systems having a sufficiently small surfactant content to be limited to two phases at the PIT. The results show that the early opinion of a phase transfer of the surfactant as the major event in the transversal of the temperature range is not entirely correct; the major phenomenon is instead an expulsion of water from the low-temperature aqueous micellar solution. In addition, the results unexpectedly give an indication of the existence of three phases at temperatures beneath the PIT, in spite of the the fact that system consists of only two phases at the actual PIT.
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| 11. |
- Cunico, Larissa P., et al.
(författare)
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Density Measurements of CO2-Expanded Liquids
- 2017
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 62:10, s. 3525-3533
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Tidskriftsartikel (refereegranskat)abstract
- Novel experimental data of density for mixtures containing CO2 + ethanol, CO2 + ethyl lactate, CO2 + glycerol + ethanol, and CO2 + glycerol + ethyl lactate at low/moderate temperatures (308 and 323 K), pressures between 5 and 30 MPa, and high amounts of the organic solvent (molar fraction x = 0.5-0.9) are presented. The chosen organic solvents (ethanol, ethyl lactate, and glycerol) are green and applicable in food industry and present different polarizabilities. The density of CO2 + ethanol increased with the increment in the molar fraction of CO2, and the opposite was observed for the mixtures of CO2 + ethyl lactate. By adding a small amount of glycerol to the mixture of CO2 + ethanol and CO2 + ethyl lactate, it was possible to increase the density even a little further. The experimental data of density were well-correlated using the Peng-Robinson equation of state (PR-EOS) combined with Péneloux volume translation.
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| 12. |
- Ekberg, Christian, 1967, et al.
(författare)
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Thermodynamics of Dissolution for Bis(triazine)-Bipyridine-Class Ligands in Different Diluents and Its Reflection on Extraction
- 2010
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Ingår i: Journal of Chemical & Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:11, s. 5133-5137
-
Tidskriftsartikel (refereegranskat)abstract
- Hydrochemical separation processes are one of the methods used for the treatment of spent nuclear fuel. Solvent extraction is also used in many other non-nuclear applications like the mining industry. In the nuclear case, hydrochemical separation processes are already employed in the world today for the recovery of uranium and plutonium. The method is however also considered for future separation systems for use in combination with the transmutation of the minor actinides. In a hydrochemical separation process the two phases are the pregnant (usually) aqueous feed and the organic phase comprising a diluent together with one or more extractants. One such class of extractants developed for partitioning and transmutation purposes is the bis(triazine)-bipyridine-type (BTBP) molecules. When assessing the feasibility and loading properties of such an extraction system, the solubility of the ligands is of the outmost importance. The understanding of whether the dissolution is enthalpically or entropically driven will also help the understanding of the differences in extraction observed between various diluents and temperatures. In this paper the enthalpy and entropy of dissolution of the BTBP-class ligands have been determined for different diluents. It has also been shown that it is possible to predict the extraction behavior of these molecules in the selected diluent once the solubility is known.
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| 13. |
- Friberg, Stig E, et al.
(författare)
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Phase inversion temperature (PIT) emulsification process
- 2011
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 56:12, s. 4282-4290
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Tidskriftsartikel (refereegranskat)abstract
- A quantitative analysis is made of the phase changes during the phase inversion temperature (PIT) emulsification process of an aqueous hexadecane emulsion stabilized by a tetra-ethylene glycol dodecyl ether surfactant. The mechanical dispersion part of the process takes place at the PIT, at which temperature the emulsion contains three phases: (1) water, with only minute fractions of surfactant and hydrocarbon; (2) an inverse micellar solution, with modest fractions of solubilized water; and (3) a bicontinuous microemulsion, with large concurrent solubilization of both water and hydrocarbon. After the mechanical action at the PIT, the emulsion is immediately cooled to temperatures beneath the PIT range, reducing the number of phases in the emulsion to two, an oil/water (O/W) microemulsion with moderate surfactant and hydrocarbon content, and an inverse micellar hydrocarbon solution with a significantly greater surfactant fraction. The emulsion is characterized by its large fraction of extremely small oil drops, significantly smaller than expected from the mechanical process. These drops are commonly assumed to emanate from the hydrocarbon fraction of the original bicontinuous microemulsion, the small size of the oil drops being a rational consequence of the colloidal dispersion prior to the phase separation. The quantitative analysis of the phase fractions versus temperature revealed this assumption to be premature. The original water phase is not the final aqueous phase in the emulsion; this phase is instead formed from the microemulsion phase by absorbing the original water phase, gradually modifying its own structure to become water-continuous with the originally large hydrocarbon fraction reduced to modest levels. In the process, a part of the original microemulsion is separated, forming the small oil drops.
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| 14. |
- Ge, Xinlei, et al.
(författare)
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A Simple Two-Parameter Correlation Model for Aqueous Electrolyte Solutions across a Wide Range of Temperatures
- 2009
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 54:2, s. 179-186
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we focused on the correlation of the thermodynamic properties of aqueous solutions across a temperature range from (273.15 to 523.15) K by a simple two-parameter model. This model is based on the modified three-characteristic-parameter correlation (TCPC) model. The two parameters, b, distance of closest approach, and S, solvation parameter, represent the interactions between ions and ions-molecules, respectively. The results show that it can adequately correlate the activity coefficient and osmotic coefficient of the single electrolyte solutions. The set of two characteristic parameters for many electrolytes was obtained. We also obtained the temperature-dependent parameters for these electrolytes. In over 70 % of the cases, six to eight parameters are necessary for an electrolyte. Compared with the Pitzer model, our model also represented a good performance.
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| 15. |
- Ge, Xinlei, et al.
(författare)
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Correlation and prediction of activity and osmotic coefficients of aqueous electrolytes at 298.15 K by the modified TCPC model
- 2007
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 52:2, s. 538-547
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Tidskriftsartikel (refereegranskat)abstract
- The modification and extension of a three-characteristic-parameter correlation model for calculating the thermodynamic properties including osmotic and mean activity coefficients of aqueous electrolytes at 298.15 K have been presented in this paper. The model can be reduced with two parameters: b, the approaching parameter, and S, the solvation parameter. Although the model adequately describes the thermodynamics with these two parameters, the third parameter, n, which is related to the distance between an ion and a solvent molecule, also can be regarded as an adjustable parameter. The two sets of parameters for 283 single salts in aqueous solutions up to saturation have been obtained from the regression of experimental values. Mean activity or osmotic coefficients of RbNO2, MgCl2, Sm(ClO4)(3), and ZnSO4, with these two sets of parameters, have been compared with the smoothed experimental data, which show good agreement. When the model with three parameters is employed, it gives a more accurate result, especially in case of high concentration. The comparison with Pitzer and the original TCPC model also illustrates the excellent performance of this modified model.
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| 16. |
- Ge, Xinlei, et al.
(författare)
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Correlation and prediction of thermodynamic properties of nonaqueous electrolytes by the modified TCPC model
- 2008
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 53:1, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the modified three-characteristic-parameter correlation model was introduced to correlate and predict the thermodynamic properties, such as the mean activity coefficient, the osmotic coefficient, and the solvent activity, of different kinds of nonaqueous electrolyte solutions. Two sets of parameters, (b, S) and (b, S, n), for 46 single salts in. methanol, ethanol, and 2-propanol, etc., were regressed from literature data at 298.15 K. Results of standard deviations showed the good applicability of our model. The calculated results of the mean activity coefficient by our model and the Pitzer model have been compared with each other with good agreement. Smoothed experimental data of osmotic coefficients and solvent activities were calculated with the present model with three or two parameters, and the one with three parameters showed a better performance. We also extended this model for some nonaqueous systems at elevated temperatures, and we also found good consistency between the results calculated from our model and experimental data. Moreover, we further developed this model for calculating those in the mixed-solvent electrolyte systems. The results showed our modified model could adequately describe these complicated electrolyte solutions.
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| 17. |
- González Escobedo, José Luis, et al.
(författare)
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Hydrodeoxygenation Model Compounds γ-Heptalactone and γ-Nonalactone : Density from 293 to 473 K and H2 Solubility from 479 to 582 K
- 2020
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2764-2773
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Tidskriftsartikel (refereegranskat)abstract
- Determining the H2 solubility in model compounds that represent lignocellulose derivatives is valuable for the study of upgrading processes such as hydrodeoxygenation. In this work, γ-heptalactone and γ-nonalactone are studied as model compounds at conditions relevant to hydrodeoxygenation. The solubility of H2 in the lactones was determined in the range of 479 to 582 K and 3 to 10 MPa. The solubility measurements were performed in a continuous flow setup based on the visual observation of the bubble point. Furthermore, the densities of the lactones were measured in order to provide the necessary data for the solubility calculations. The density measurements were performed from 293 to 373 K and from 0.16 to 9.9 MPa in a vibrating tube density meter. Using the measurements, a model of the density as a function of temperature and pressure was developed, obtaining average relative deviations on the order of 0.1%. Similarly, the Peng-Robinson equation of state with the Boston-Mathias modification was used to predict the H2 solubility in the lactones. A temperature-dependent model of the symmetric binary parameter of the equation of state was regressed from the data in order to improve the predictions.
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| 18. |
- Gracin, Sandra, et al.
(författare)
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Solubility of Phenylacetic Acid, p-Hydroxyphenylacetic Acid, p-Aminophenylacetic Acid, p-Hydroxybenzoic Acid, and Ibuprofen in Pure Solvents
- 2002
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 47:6, s. 1379-1383
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of phenyl acetic acid, p-hydroxyphenylacetic acid, p-aminophenylacetic acid, p-hydroxybenzoic acid, and ibuprofen in water and in a range of organic solvents of relevance to industrial processing is reported. The solvents used are water, methanol, ethanol, 2-propanol, acetone, 4-methyl-2-pentanone, ethyl acetate, chloroform, and toluene. Solubility data are discussed from the standpoint of molecular aspects of solute-solvent interactions and by estimated solid-phase activity.
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| 19. |
- Granberg, R. A., et al.
(författare)
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Solubility of paracetamol in binary and ternary mixtures of water + acetone + toluene
- 2000
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 45:3, s. 478-483
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of paracetamol (4-hydroxyacetanilide) in binary mixtures of acetone + water and acetone + toluene and in ternary mixtures of water + acetone + toluene is reported. The temperature range is -5 to +30°C. In acetone + water the solubility increases to a maximum at approximately 25 mass % water before decreasing to a much lower value in pure water as compared to pure acetone. In acetone + toluene the solubility decreases monotonically with increasing toluene concentration. The water content has a strong influence also in ternary mixtures. Activity coefficients in the saturated solutions are estimated.
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| 20. |
- Granberg, R. A., et al.
(författare)
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Solubility of paracetamol in pure solvents
- 1999
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 44:6, s. 1391-1395
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Tidskriftsartikel (refereegranskat)
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| 21. |
- Huang, Mian-Mian, et al.
(författare)
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Static Relative Dielectric Permittivities of Ionic Liquids at 25 °C
- 2011
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 56:4, s. 1494-1499
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Tidskriftsartikel (refereegranskat)abstract
- For understanding solvation by ionic liquids, it is mandatory to characterize their static relative dielectric permittivities ε (“static dielectric constants”). Exploiting the definition of ε in terms of the zero-frequency limit of the frequency-dependent dielectric dispersion curve, the static dielectric constant of an electrically conducting liquid can be extrapolated from dielectric relaxation spectra in the microwave regime. On the basis of this method, we report dielectric constants of 42 ionic liquids at 25 °C.
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| 22. |
- Hull, A, et al.
(författare)
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Vapour-liquid equilibrium of binary mixtures. 1. Ethanol-1-butanol, ethanol + octane, 1-butanol + octane
- 2006
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Ingår i: Journal of Chemical and Engineering Data. - 0021-9568 .- 1520-5134. ; 51, s. 1996-2001
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Tidskriftsartikel (refereegranskat)abstract
- The activity coefficients of the binary mixtures ethanol + 1-butanol, ethanol + octane, and 1-butanol + octane were determined at temperatures of (308.15, 313.15, and 318.15) K. The determination of the vapor phase composition at equilibrium was carried out using headspace gas chromatography analysis. Multiple headspace extraction was used to calibrate the headspace gas chromatograph. Comparison of the phase diagrams produced using standard Legendre orthogonal polynomial techniques with phase diagrams from the literature showed good agreement. The composition of the azeotropes were reported, where applicable.
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| 23. |
- Hull, A, et al.
(författare)
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Vapour-liquid equilibrium of binary mixtures. 2. Ethanol + 2,2,4-trimethylpentane, 1-butanol + 2,2,4-trimethylpentane, and ethanol + o-xylene
- 2006
-
Ingår i: Journal of Chemical and Engineering Data. - 0021-9568 .- 1520-5134. ; 51, s. 2002-2008
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Tidskriftsartikel (refereegranskat)abstract
- The activity coefficients of the binary mixtures ethanol + 2,2,4-trimethylpentane, 1-butanol + 2,2,4-trimethylpentane, and ethanol + o-xylene were determined at temperatures of (308.15, 313.15, and 318.15) K. The determination of the vapor phase composition at equilibrium was carried out using headspace gas chromatography analysis. Multiple headspace extraction was used to calibrate the headspace gas chromatograph. Comparison of the experimental phase diagrams with phase diagrams from the literature shows good agreement. The composition of the azeotropes are reported, where they exist. The molar Gibbs energy of mixing is reported for all mixtures studied. The infinite dilution activity coefficients are reported for all components of all mixtures. Some thermodynamic models (those of Wilson, NRTL, UNIQUAC, and Flory-Scatchard) have been compared with regard to their suitability for modeling the experimental data.
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| 24. |
- Ji, Xiaoyan, et al.
(författare)
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Activity coefficients of HCl in the HCl + NH4Cl + H2O systems at 298.15 and 313.15 K
- 2000
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 45:1, s. 29-33
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Tidskriftsartikel (refereegranskat)abstract
- Using the ion-selective electrode method with a concentrated electrolyte solution added continuously, the mean activity coefficients of HCl in the HCl + NH4Cl + H2O system were experimentally measured at 298.15 and 313.15 K and at five molality fractions of NH4Cl (y2 = mNH4Cl/(mHCl + mNH4Cl) from 0.1 to 0.9. The measurements were made by an electrochemical cell using a H glass ion-selective electrode and a chloride solid-state ion-selective electrode. It was found that the influence of NH4+ on the H glass ion-selective electrode could be neglected up to 1.3 molkg-1, and this pair of ion-selective electrodes was suitable for determining the activity coefficients of HCl in the system. A new set of Pitzer mixing parameters, correlated from the experimental results, was used to calculate the activity coefficients for HCl in the system from 293.15 to 313.15 K up to 3.0 molkg-1.
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| 25. |
- Liu, Jing-fu, et al.
(författare)
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Ionic liquids/water distribution ratios of some polycyclic aromatic hydrocarbons
- 2004
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 1520-5134 .- 0021-9568. ; 49:5, s. 1422-1424
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Tidskriftsartikel (refereegranskat)abstract
- By using the shake-flask procedure, the distribution ratios (D) at infinite dilution and 298.1 K of 15 polycyclic aromatic hydrocarbons (PAHs) between room-temperature ionic liquids, 1-alkyl-3-methylimiazolium hexafluorophosphates ([CnMIM] [PF6], n = 4 and 8), and water were determined. The log D values are in the range of 3.34-4.36, which increased very slowly with the molar mass of PAHs.
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