| 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
-
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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| 26. |
- Lodeiro, Pablo, et al.
(författare)
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Solid–Liquid Equilibria in Aqueous Solutions of Tris, Tris-NaCl, Tris-TrisHCl, and Tris-(TrisH)2SO4 at Temperatures from 5 to 45 °C
- 2021
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 66:1, s. 437-455
-
Tidskriftsartikel (refereegranskat)abstract
- The substance Tris (or THAM, 2-amino-2-hydroxymethyl-1,3-propanediol) is used in the preparation of pH buffer solutions for applications in natural water chemistry, including seawater. The development of a chemical speciation model of buffer solutions containing Tris, TrisH+, and the major ions of seawater is desirable, so that the effects of changes in the composition and concentration of the medium on pH can be calculated. The Pitzer activity coefficient equations, commonly used in such speciation models, describe the thermodynamic properties of solutions in terms of interactions between dissolved ions and uncharged solute species. To determine some of these interactions, we have measured solubilities of Tris(s) in water and aqueous solutions of NaCl, TrisHCl, and (TrisH)2SO4 and the solubility of NaCl(s) in aqueous Tris(aq), from 5 to 45 °C. We report measurements of the water activities of Tris solutions at 293.5 K to high supersaturation with respect to the solid. Using the Pitzer equations, we compare our results to literature data yielding stoichiometric dissociation constants of TrisH+ in aqueous NaCl, and to electromotive forces of cells containing dissolved Tris, TrisHCl, and NaCl. Values of parameters for the interactions of Tris with the ions TrisH+, Na+, and SO42– at 25 °C are determined.
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| 27. |
- Lützenkirchen, Johannes, et al.
(författare)
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Comparison of various models to describe the charge−pH dependence of Poly(acrylic acid)
- 2011
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 56:4, s. 1602-1612
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Tidskriftsartikel (refereegranskat)abstract
- The charge of poly(acrylic acid) (PAA) in dilute aqueous solutions depends on pH and ionic strength. We report new experimental data and test various models to describe the deprotonation of PAA in three different NaCl concentrations. A simple surface complexation approach is found to be very successful: the constant capacitance model requires one pKa value and one capacitance for excellent fits to the data, with both parameters depending on ionic strength. The use of a self-consistent set of diffuse double layer parameters with one pKa for flat, spherical, and cylindrical geometry does not result in a satisfactory description of the data, and a number of adjustments to that model were tested to improve the fit. The basic Stern model (BSM) was tested with both plate and cylinder geometry. The cylinder geometry along with strong electrolyte binding was found to be superior to a similar approach involving weak electrolyte binding both in terms of goodness of fit and self-consistency of the parameters. The third approach, the non-ideal competitive consistent adsorption-Donnan (NICCA-Donnan) model, involving one functional group, allows an excellent description of the experimental data. Finally, the polyacid chain was modeled using a mechanistically more realistic self-consistent field (SCF) approach, which allows for radially inhomogeneous distributions of the charges and radial variations in the polymer density and electrostatic potential, while the functional groups can be in protonated, deprotonated, or complexed states. One functional group was insufficient for a satisfactory description of the data. With two segments (one monoprotic, the other diprotic) a reasonable description of the data, including the ionic strength dependence, is achieved, and the tendency of the size of the macro-ion with pH and ionic strength is as expected. This model has the fewest adjustable parameters and is considered the most realistic and comprehensive among the models tested.
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| 28. |
- Ma, Chunyan, et al.
(författare)
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Molar Enthalpy of Mixing for Choline Chloride/Urea Deep EutecticSolvent + Water System
- 2016
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 61:12, s. 4172-4177
-
Tidskriftsartikel (refereegranskat)abstract
- The molar enthalpies of mixing for binary systems of choline chloride (chcl)/urea deep eutectic solvents (mole ratios of 1:1.5, 1:2, and 1:2.5) with water were measured at 308.15 and 318.15 K under atmospheric pressure with an isothermal calorimeter. The binary mixture of (chcl/urea (1:2.5) + water) showed endothermic behavior over the entire range of compositions, while the binary mixtures of (chcl/urea (1:1.5) + water) and (chcl/urea (1:2) + water) showed endothermic behavior first and then was changed to be exothermic with increasing content of deep eutectic solvents. The Redlich–Kister (RK) equation and the nonrandom two-liquid (NRTL) model were used to fit experimental molar enthalpies of mixing. The NRTL model with the fitted parameters was further used to predict the vapor pressure for the three systems and was compared with the experimental data from literature. For the binary mixtures of (chcl/urea (1:2) + water), the predicted vapor pressure agreed well with the experimental data only when the temperature was lower than 333.15 K and the mole fraction of chcl/urea (1:2) was lower than 0.1. Otherwise, the deviation increased greatly with an increase of the amount of chcl/urea (1:2).
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| 29. |
- Maher, Anthony, et al.
(författare)
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Solubility of form III piracetam in a range of solvents
- 2010
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:11, s. 5314-5318
-
Tidskriftsartikel (refereegranskat)abstract
- The polymorph known as Form III of 2-oxo-1-pyrrolidine acetamide (piracetam) was isolated by cooling crystallization from methanol and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Form III is the thermodynamically stable polymorph of piracetam in the range of this solubility study. The solubility of Form III was determined by gravimetrically measuring the amount of Form III which was contained in a volume of saturated solution over the temperature range (278 to 323) K, following evaporation of the solvent. Five solvents were examined: methanol, ethanol, 2-propanol, acetone, and 1,4-dioxane. The results showed that the solubility values correlated positively with solvent polar characteristics from a qualitative point of view; an increase in solubility of Form 111 was observed with increasing solvent polarity and solvent acidity. As the number of carbons in the n-alcohols increases, the polarity of the solvent and its hydrogen donation ability decreases and so does the solubility of Form III in the solvent. 1,4-Dioxane and acetone are relatively nonpolar and non-hydrogen bond donating solvents compared to the n-alcohols, and accordingly Form III is much less soluble in these.
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| 30. |
- Maher, A., et al.
(författare)
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Solubility of the metastable polymorph of piracetam (Form II) in a range of solvents
- 2012
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 57:12, s. 3525-3531
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Tidskriftsartikel (refereegranskat)abstract
- The solid-liquid solubility of the polymorph known as Form II of 2-oxo-1-pyrolidine acetamide (Piracetam) has been determined gravimetrically in different solvents. Form II is the metastable polymorph of piracetam at ambient conditions and has been isolated and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Monitoring the solution concentration and the polymorphic composition of the solid phase displayed that this metastable form has a sufficient lifetime when in contact with the solvents to allow measurement of its solubility over the temperature range (278 to 323) K. Four solvents are included: ethanol, 2-propanol, acetone, and 1,4-dioxane. The results show that the solubility of Form II increases with increasing solvent polarity and solvent acidity. Form II has a slightly higher solubility than the stable Form III in all solvents at all temperatures, but the solubility difference is very small. Since Form II is known to transform to Form I below its melting point, a set of regression equations which can be used to extrapolate solubility data to the melting point of Form II were applied to the collected data.
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| 31. |
- Matsushita, Taishi, et al.
(författare)
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Studies of the Thermophysical Properties of Commercial CMSX-4 Alloy
- 2009
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 54:9, s. 2584-2592
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, measurements of the heat capacities and thermal diffusivities of commercial CMSX-4 nickel-based superalloy are described, and the results are presented. Since the as-received commercial alloy sample is not at the thermodynamic equilibrium state, the phases present in the alloy undergo transformations toward equilibrium state as the measurements are made at temperatures above which the rate of transformation can be significant. The microstructures of the as-received sample as well as heat treated samples were observed, and the relation with the properties was discussed. The results are discussed considering the phase changes Occurring with the thermodynamic equilibrium state as the reference. The results are of great relevance in the performance of these alloys in industrial applications.
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| 32. |
- Mikola, M., et al.
(författare)
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Liquid-Liquid Equilibria for the n-Pentyl acetate, n-Hexyl acetate, n-Pentanol, or n-Hexanol + Furfural + Water Systems at 298 and 323 K
- 2021
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 210-221
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, four ternary liquid-liquid equilibrium systems containing a solvent, furfural, and water were investigated by performing liquid-liquid equilibrium measurements at two different temperatures. The solvents were n-pentyl acetate, n-hexyl acetate, n-pentanol, and n-hexanol. The measurements were compared to the literature data and modeled with the UNIQUAC (universal quasi-chemical) activity coefficient model by taking into account also the vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibrium behaviors if present. n-Hexyl acetate showed the smallest solubility in water both in binary and ternary measurements. All four ternary systems showed similar magnitude distribution coefficients but furfural had the highest selectivity to n-hexyl acetate. Among the four systems investigated in this work, n-hexyl acetate was observed to have the best characteristics as a solvent for the extraction of furfural from water. © 2020 American Chemical Society.
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| 33. |
- Monteserin, Maria, et al.
(författare)
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Multicomponent Interdiffusion and Self-Diffusion of the Cationic Poly{[9,9-bis(6 '-N,N,N-trimethylammonium)hexyl]fluorene-phenylene} Dibromide in a Dimethyl Sulfoxide plus Water Solution
- 2010
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 1520-5134 .- 0021-9568. ; 55:5, s. 1860-1866
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Tidskriftsartikel (refereegranskat)abstract
- The diffusion behavior of the conjugated polyelectrolyte poly{[9,9-bis(6'-N,N,N-trimethylammonium)hexyl]fluorene-phenylene) bromide (HTMA-PFP) with different molecular weights has been studied in dimethyl sulfoxide (DMSO) + water solutions. Samples of HTMA-PFP with various molecular weights were obtained by synthesis of poly[9,9-bis(6'-bromohexyl)fluorene-phenylene] via a Suzuki coupling reaction, characterized by size exclusion chromatography (SEC), and quaternized with trimethylamine. Multicomponent chemical interdiffusion coefficients (mutual diffusion coefficients) were determined for solutions of HTMA-PFP and DMSO in water using the Taylor dispersion method. The results suggest specific interactions between the DMSO and the polymer. In addition, these systems were studied by pulse-field gradient nuclear magnetic resonance spectroscopy (PFG-NMR), and the corresponding self-diffusion coefficients were obtained. These were modeled using the Kirkwood-Riseman model, and a good fit to the observed behavior was obtained using literature data for molecular dimensions.
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| 34. |
- Nordström, Fredrik, et al.
(författare)
-
Solubility and Melting Properties of Salicylamide
- 2006
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 51:5, s. 1775-1777
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of salicylamide in methanol, acetonitrile, acetic acid, acetone, water, and ethyl acetate has been determined between (10 to 50) degrees C. The onset melting temperature and enthalpy of fusion has been determined by differential scanning calorimetry to 138.7 degrees C and 29.0 kJ center dot mol(-1), respectively. Only the monoclinic structure of salicylamide was observed at crystallization.
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| 35. |
- Nordström, Fredrik, et al.
(författare)
-
Solubility and Melting Properties of Salicylic acid
- 2006
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 51:5, s. 1668-1671
-
Tidskriftsartikel (refereegranskat)abstract
- The solubility of salicylic acid has been investigated in methanol, acetonitrile, acetic acid, acetone, water, and ethyl acetate from (10 to 50) degrees C. No new polymorphs or solvates of salicylic acid were found. The melting properties of salicylic acid were determined by differential scanning calorimetry. A correlation was observed between the solubility and the van't Hoff enthalpy of solution. A higher solubility was related to a lower van't Hoff enthalpy of solution. Water differed from the organic solvents in terms of solubility and its correlation to the van't Hoff enthalpy of solution. In addition, the morphology of salicylic acid crystals recrystallized from water differed from the other solvents.
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| 36. |
- Okeme, Joseph, et al.
(författare)
-
Gas chromatographic estimation of vapor pressures and octanol-air partition coefficients of semivolatile organic compounds of emerging concern
- 2020
-
Ingår i: Journal of Chemical and Engineering Data. - Washington, DC, USA : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2467-2475
-
Tidskriftsartikel (refereegranskat)abstract
- The subcooled liquid-phase vapor pressures (pL298/Pa) and octanol–air partition coefficients (KOA298) at T/K = 298, enthalpies of vaporization (ΔVAPH/kJ·mol–1), and internal energies of phase transfer from octanol to air (ΔOAU/kJ·mol–1) were estimated for synthetic musks, novel brominated flame retardants (N-BFR), organophosphate esters, and ultraviolet filters using the capillary gas chromatographic retention time (GC-RT) method. These compounds, which spanned approximately six and three orders of magnitude for pL298/Pa and KOA298, respectively, were co-chromatographed with one of three reference compounds to give initial estimates of properties at T/K = 298. The initial GC-RT property estimates were subsequently calibrated using 18 compounds that spanned 6 log units for pL298/Pa and 13 compounds covering 4 log units for KOA298. The calibrated log10pL298/Pa values estimated here ranged from 0.14 ± 0.19 to −9.19 ± 0.29 for cyclopentadecanone to syn-dechlorane plus (syn-DDC-CO), respectively, while the range of log10KOA298 values was 6.59 ± 0.26 to 11.40 ± 0.23 for cyclopentadecanone to 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99), respectively. The calibrated GC-RT-derived values were highly correlated with, and were within an average of 0.70 log units of, the literature data for compounds with well-established pL298/Pa and KOA298 measured or derived using non-GC-RT methods. Nonpolar compounds were used in this study to estimate the target polar compound data, which may introduce systematic errors. However, the comparison of our GC-RT results against the literature non-GC-RT values shows that the GC-RT methods performed similarly well for estimating both polar and nonpolar target compounds studied in this work.
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| 37. |
- Panagopoulos, Dimitri, et al.
(författare)
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Evaluating the salting-out effect on the organic carbon/water partition ratios (KOC and KDOC) of linear and cyclic volatile methylsiloxanes : Measurements and polyparameter linear free energy relationships
- 2016
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 61:9, s. 3098-3108
-
Tidskriftsartikel (refereegranskat)abstract
- Dissolved inorganic salts influence the partitioning of organic chemicals between water and sorbents. We present new measurements of the salting-out constants (Ks) for partition ratios between water and organic carbon (KOC) and between water and dissolved organic carbon (KDOC) of three cyclic volatile methylsiloxanes (cVMS), two linear volatile methylsiloxanes (lVMS), three polychlorinated biphenyls (PCBs), and α-hexachlorocyclohexane (α-HCH). Ks, KOC, and KDOC were derived from volatilization rates of the chemicals from mixtures of water and organic carbon with varying concentrations of sodium chloride in a purge-and-trap system. KOC and KDOC values at different salinities were determined by fitting their values to reproduce observed volatilization rates using a fugacity-based multimedia model and assuming first-order kinetics for volatilization. The Ks values of cVMS and lVMS ranged from 0.16–0.76. The log KOC of cVMS and lVMS in fresh water interpolated from our measurements ranged from 5.20 to 7.36 and the log KDOC values from 5.04 to 6.72. Polyparameter linear free energy relationships (PP-LFERs) trained with data sets without measurements for siloxanes failed to accurately describe the log KOC and log KDOC of cVMS and lVMS. Including our measurements for cVMS and lVMS substantially improved the fit. PP-LFERs trained with data for Ks from solubility measurements do not describe our new measurements well regardless of whether or not they are included in the training set, which may reflect differences in the salting-out effect on partitioning to organic carbon versus on solubility.
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| 38. |
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| 39. |
- Qasim, Ali, et al.
(författare)
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Effect of Hydrogen Bonding Energy and Freezing Point Depression of Quaternary Ammonium Salts on the Thermodynamic Gas Hydrate Inhibition
- 2023
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 68:8, s. 1856-1864
-
Tidskriftsartikel (refereegranskat)abstract
- Theeffects of the hydrogen bonding energy interactionand freezingpoint depression on five quaternary ammonium salts (QAS) of gas hydratesystems are discussed in this study. Tetramethylammonium bromide,tetraethylammonium bromide, tetramethylammonium acetate, tetraethylammoniumacetate tetrahydrate, and tetramethylammonium iodide were among theQAS studied. Methane (CH4) and carbon dioxide (CO2), frequently encountered in flow assurance pipelines, are includedin the considered hydrate system. The experimental temperature rangeis 274-285 K, with 3.40-8.30 and 2.0-4.0 as thecorresponding pipeline pressures for CH4 and CO2. For different mass concentrations (1, 5, and 10 wt.%), the thermodynamicinfluence, i.e., average suppression temperature (& UDelta; T ), of the studied system was reported, and itsrelationship with the hydrogen bonding energy (E (HB)) interaction and freezing point temperature (T (f)) of QAS was investigated. The structural impact of QAS(in the form of alkyl chain variation) and anions on thermodynamichydrate inhibition (THI) behavior via hydrogen bonding energy interactionsand freezing point is also covered in the research. According to thefindings, the increase in the alkyl chain length of QAS reduced thedecrease in E (HB) bonding ability. On theother hand, the presence of an anion had a significant impact on QAS.The E (HB) and QAS freezing T (f) are concentration-dependent phenomena; higher QAS concentrationin the system resulted in lower T (f) temperaturesand higher E (HB) energies, which influencedhydrate mitigation positively. The work is novel as it establishesthe relationship between E (HB) and averagesuppression temperature and also between depression in freezing pointwith average suppression temperature. Since QAS are considered amongpotential THI inhibitors, further development is required for a generalizedcorrelation based on the E (HB) interactionand T (f).
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| 40. |
- Sarmad, Shokat, 1976-, et al.
(författare)
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Measurement and correlation of phase equilibria for poly(ethylene glycol) methacrylate + alcohol systems at 298.15 K
- 2005
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 50:1, s. 283-287
-
Tidskriftsartikel (refereegranskat)abstract
- The activities of methanol, ethanol, 2-propanol, and 1-butanol in poly(ethylene glycol) methacrylate (Mn = 360) solutions have been measured by the isopiestic method at 298.15 K. Sodium iodide and calcium chloride were used as the isopiestic standards for the calculation of activities. The original equation of Flory−Huggins and the modified Flory−Huggins equation with concentration-dependent interaction parameters have been used for the correlation of the experimental solvent activity data. The strength of interaction between different alcohols and the polymer was discussed on the basis of the obtained Flory−Huggins interaction parameters. The reliability of the two local-composition models, NRTL and NRF, were also assessed by fitting the experimental activity data to these models. All of these models satisfactorily present the obtained experimental activity data
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| 41. |
- Ström, Krister, 1956, et al.
(författare)
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Density for Water + Ethylenediamine at Temperatures between 283 and 353 K
- 2008
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Ingår i: Journal of Chemical & Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 53:10, s. 2307-2310
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Tidskriftsartikel (refereegranskat)abstract
- The density for mixtures of ethylenediamine (EDA) and water at 0.2 MPa was measured with a vibrating tube densitometer in the temperature range of 283 K to 353 K at intervals of 10 K. The entire composition range was covered with intervals of molar fractions of 10 %. The excess volume has a minimum at a molar fraction of water of 59 %, corresponding to a maximum at 69 % in the departure from additivity in density. The variation with temperature in excess volume is small, but for density it is complex. The temperature dependence in density is well described by combining a Redlich-Kister model for excess volume without temperature dependent parameters with models for the pure component densities.
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| 42. |
- Svärd, Michael, et al.
(författare)
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Calorimetric Properties and Solubility in Five Pure Organic Solvents of N-Methyl-D-Glucamine (Meglumine)
- 2016
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 61:3, s. 1199-1204
-
Tidskriftsartikel (refereegranskat)abstract
- The solid liquid solubility of the title compound has been measured by a gravimetric method in five pure organic solvents over the temperature range (283 to 323) K. The melting temperature and associated enthalpy of fusion have been determined by differential scanning calorimetry (DSC), and the heat capacity of the solid and the melt have been determined over a range of temperatures by means of temperature-modulated DSC. Melting data and the extrapolated difference in heat capacity between the melt and the solid have been used to calculate the Gibbs energy, enthalpy, and entropy of fusion and the ideal solubility from below ambient temperature to the melting point. On the basis of estimated activity coefficients at equilibrium, solutions in all the five solvents are shown to exhibit positive deviation from Raoult's law. The highest mole fraction solubility is observed in methanol, and all van't Hoff solubility curves are nonlinear. Solubility data is well correlated by a recently proposed semiempirical regression model.
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| 43. |
- Thati, Jyothi, et al.
(författare)
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Solubility of Benzoic Acid in Pure Solvents and Binary Mixtures
- 2010
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:11, s. 5124-5127
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of benzoic acid has been determined in ethanol, toluene, heptane, cyclohexane, pentane, and chloroform and in binary mixtures of ethanol + heptane and ethanol toluene, in the temperature range of (278.15 to 323.15) K. The solubility is high in ethanol, reasonably high in chloroform, lower in toluene, and quite low in the remaining three pure solvents. In the binary mixtures the solubility of benzoic acid increases with increasing concentration of ethanol. The solubility of benzoic acid increases with increasing temperature.
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| 44. |
- Touronen, J, et al.
(författare)
-
Application of GaInSn Liquid Metal Alloy Replacing Mercury in a Phase Equilibrium Cell: Vapor Pressures of Toluene, Hexylbenzene, and 2-Ethylnaphthalene
- 2020
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:7, s. 3270-3276
-
Tidskriftsartikel (refereegranskat)abstract
- Mercury has been applied as a sealing and pressure transmission fluid in many experimental phase equilibrium studies employing the synthetic visual method as well as a moving piston in analytical isobaric and/or isothermal methods. However, mercury is highly toxic and therefore its use is restricted by authorities such as those of the European Union. A new apparatus employing nontoxic GaInSn liquid metal alloy as a sealing, moving piston, and pressure transmission fluid for phase equilibrium measurements with a nonvisual variable volume method is presented. The vapor pressures of toluene, hexylbenzene, and 2-ethylnaphtalene are provided within the applied temperature range of 400-620 K. New values for the parameters of the DIPPR 101 and Wagner equations, and PC-SAFT equation of state were regressed. The results demonstrate that GaInSn can be used in phase equilibrium cells as a very convenient substitute for mercury, especially at high temperatures.
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| 45. |
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| 46. |
- Vielma, T., et al.
(författare)
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A Volumetric Pitzer Model for Aqueous Solutions of Zinc Sulfate up to Near-Saturation Concentrations at Temperatures from 293.15 to 393.15 K and Pressures up to 10 MPa
- 2021
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 58-64
-
Tidskriftsartikel (refereegranskat)abstract
- Literature data for the volumetric properties of aqueous solutions of zinc sulfate have been compiled and compared with extensive recently available measurements. A semi-empirical Pitzer model has been derived from these data that reproduces the apparent molar volumes and compressibilities of zinc sulfate solutions with good accuracy to near-saturation concentrations (m 3.0 mol·kg-1) over the temperature range 293.15 ≤ T/K ≤ 393.15 and at pressures up to 10 MPa, using standard volumes, V°, obtained by additivity of ionic values from the literature. By including the dependence of V° on the compressibility of pure water, the model was able to predict apparent molar volumes with good accuracy even up to 100 MPa at 298 K. Of potential use for engineering applications, imposition of the inequality (-2Vφ/-T2)p,m < 0 to the Pitzer model has created the possibility of physically reasonable extrapolations to temperatures well beyond the parameterization range. © 2020 American Chemical Society.
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| 47. |
- Vielma, T., et al.
(författare)
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Volumetric Properties of Aqueous Solutions of Zinc Sulfate at Temperatures from 298.15 to 393.15 K and Pressures up to 10 MPa
- 2021
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society. - 0021-9568 .- 1520-5134. ; 66:1, s. 45-57
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Tidskriftsartikel (refereegranskat)abstract
- Densities of aqueous solutions of zinc sulfate at molalities ranging from 0.1 to 3.0 mol·kg-1 were measured with a commercial vibrating tube densimeter at temperatures from 298.15 to 393.15 K and at pressures up to 10 MPa. Comparison between the present values and literature data showed a good agreement in general; however, a direct comparison could be made only at 298.15 K. Isothermal compressibilities derived from the density measurements as a function of pressure also compared favorably with literature values based on speed-of-sound measurements. ©
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| 48. |
- Wang, Yanxin, et al.
(författare)
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Thermodynamic Study of Choline Chloride-Based Deep Eutectic Solvents with Water and Methanol
- 2020
-
Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 65:5, s. 2446-2457
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Tidskriftsartikel (refereegranskat)abstract
- To study the effects of type and content of cosolvent as well as temperature on the properties of two well-known deep eutectic solvents (DESs), i.e., ChCl/EG (choline chloride + ethylene glycol at a molar ratio of 1:2) and ChCl/Gly (choline chloride and glycerol at a molar ratio of 1:2), the density and viscosity of the mixtures of ChCl/EG or ChCl/Gly with methanol (MeOH) and water (H2O) over the whole compositional range at temperatures from 288.15 to 323.15 K as well as the molar enthalpy of mixing for the mixtures of ChCl/EG or ChCl/Gly + MeOH were experimentally measured. The excess molar volume, viscosity deviation, and excess molar Gibbs energy of activation were further calculated to study the effects of temperature, types of cosolvent and DES, and their contents on the nonideal behavior of these pseudobinary systems. The molar enthalpy of mixing measured in this work was further compared with those with H2O as the cosolvent reported in the literature. It shows that the mixing of these two DESs with MeOH is exothermic, which is opposite compared to those mixed with H2O. Additionally, the nonrandom two-liquid model and Gibbs–Helmholtz equation were combined to represent the experimental results of the enthalpy of mixing.
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| 49. |
- Xie, Yujiao, et al.
(författare)
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Effect of Water on the Density, Viscosity, and CO2 Solubility in Choline Chloride/Urea
- 2014
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 59:11, s. 3344-3352
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Tidskriftsartikel (refereegranskat)abstract
- To study the effect of water on the properties of choline chloride (ChCl)/urea mixtures (1:2 on a molar basis), the density and viscosity of ChCl/urea (1:2) with water were measured at temperatures from 298.15 K to 333.15 K at atmospheric pressure, the CO2 solubility in ChCl/urea (1:2) with water was determined at 308.2 K, 318.2 K, and 328.2 K and at pressures up to 4.5 MPa. The results show that the addition of water significantly decreases the viscosity of ChCl/urea (1:2), whereas the effects on their density and CO2 solubility are much weaker. The CO2 solubility in ChCl/urea (1:2) with water was represented with the Nonrandom-Two-Liquid Redlich–Kwong (NRTL-RK) model. The excess molar volume and excess molar activation energy were further determined. The CO2 absorption enthalpy was calculated and dominated by the CO2 dissolution enthalpy, and the magnitude of the CO2 dissolution enthalpy decreases with the increase of water content.
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| 50. |
- Yang, Huaiyu, et al.
(författare)
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Solubility of Butyl Paraben in Methanol, Ethanol, Propanol, Ethyl Acetate, Acetone, and Acetonitrile
- 2010
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 55:11, s. 5091-5093
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of butyl paraben (butyl 4-hydroxybenzoate) have been determined in methanol, ethanol, propanol, acetone, ethyl acetate, and acetonitrile in the temperature range of (10 to 50) C by the gravimetric method. The order of the solubility of butyl paraben in the different solvents as mass fraction at 20 C is: methanol > ethanol > acetone > propanol > ethyl acetate > acetonitrile. In terms of mole fraction solubility, the corresponding order is acetone > propanol > ethanol > ethyl acetate > methanol > acetonitrile, which shows that both nonpolar and polar groups of the paraben molecule influence the solubility in the different solvents.
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