Effects of hydration on the thermodynamic properties of aqueous ethylene glycol ether solutions

Schrödle, Simon; Hefter, Glenn; Buchner, Richard

doi:10.1016/j.jct.2004.10.006

Cited by 24 publications

(29 citation statements)

References 40 publications

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“…Beyond these compilations a large number of recent papers presenting the heat-capacity data of several classes of compounds and of individual molecules of any kind as well as their temperature dependence have been published up to the present. Special mention shall be given to the hydrocarbons [49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65], halogenated hydrocarbons [66,67,68,69,70,71], unsubstituted and substituted alcohols and polyols including sugar derivatives [72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107], phenol derivatives [108,109], carboxylic acids […”

Section: Resultsmentioning

confidence: 99%

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their “True” Molecular Volume

Naef

2019

Molecules

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A universally applicable method for the prediction of the isobaric heat capacities of the liquid and solid phase of molecules at 298.15 K is presented, derived from their “true” volume. The molecules’ “true” volume in A3 is calculated on the basis of their geometry-optimized structure and the Van-der-Waals radii of their constituting atoms by means of a fast numerical algorithm. Good linear correlations of the “true” volume of a large number of compounds encompassing all classes and sizes with their experimental liquid and solid heat capacities over a large range have been found, although noticeably distorted by intermolecular hydrogen-bond effects. To account for these effects, the total amount of 1303 compounds with known experimental liquid heat capacities has been subdivided into three subsets consisting of 1102 hydroxy-group-free compounds, 164 monoalcohols/monoacids, and 36 polyalcohols/polyacids. The standard deviations for Cp(liq,298) were 20.7 J/mol/K for the OH-free compunds, 22.91 J/mol/K for the monoalcohols/monoacids and 16.03 J/mol/K for the polyols/polyacids. Analogously, 797 compounds with known solid heat capacities have been separated into a subset of 555 OH-free compounds, 123 monoalcohols/monoacids and 119 polyols/polyacids. The standard deviations for Cp(sol,298) were calculated to 23.14 J/mol/K for the first, 21.62 J/mol/K for the second, and 19.75 J/mol/K for the last subset. A discussion of structural and intermolecular effects influencing the heat capacities as well as of some special classes, in particular hydrocarbons, ionic liquids, siloxanes and metallocenes, has been given. In addition, the present method has successfully been extended to enable the prediction of the temperature dependence of the solid and liquid heat capacities in the range between 250 and 350 K.

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Section: Resultsmentioning

confidence: 99%

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their “True” Molecular Volume

Naef

2019

Molecules

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“…Concentrations are thus accurate to four digits. Densities were taken from the literature 12 and checked by vibrating tube densitometry (Anton Paar DMA 60/602 system).…”

Section: Experimental Details and Data Processingmentioning

confidence: 99%

Dielectric Spectroscopy of Hydrogen Bond Dynamics and Microheterogenity of Water + Dioxane Mixtures

2007

Self Cite

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Mixtures of water or D2O + 1,4-dioxane (DX) have been studied at 25 degrees C by dielectric relaxation spectroscopy over a wide range of frequencies (0.2 < or = nu/GHz < or = 89) for DX mole fractions 0 < or = x2 < or = 0.67. The spectra were best fitted by the sum of two Debye terms. The slower process was assigned to the cooperative relaxation of the hydrogen-bond network of water, whereas the faster mode reflects the dynamics of H2O molecules in a DX-rich environment. Analysis of the relaxation parameters revealed a largely microheterogeneous structure of the mixtures. The marked slowing-down of the cooperative mode on addition of DX is ascribed to the reduction of available H-bond acceptor sites and geometrical constraints on the H2O molecules in the water-rich regions.

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“…The graphical illustration of the fits of the thermal data is shown in Figures 3 and 4. As seen in Figure 3 for the (water + G3) system, the H E (x 1 ) and C p E (x 1 ) data selected for the correlation, measured at 298.15 K accurately by Birošet al 12 and Schrodle et al, 15 respectively, are captured perfectly. On the other hand, the C p E data of Mundhwa et al 25 (not involved in the correlation database) are seen to be appreciably deviating from both Schrodle et al's data and the fit and also considerably scattered.…”

Section: Simultaneous Correlation Of Activity and Calorimetricmentioning

confidence: 72%

“…Apart from the present water activity data obtained at two temperatures, the databases for the correlations comprised classical excess enthalpy data H E (x 1 ) covering the whole composition range, 12,13 dissolution enthalpies of glymes at infinite dilution in water Δ sol H 2 ∞ obtained by specialized calorimetric measurements, 14 and in case of G3, also excess heat capacity data C p E . 15 The adjustable parameters of the model were evaluated by the weighted least squares method minimizing the objective function…”

Section: Simultaneous Correlation Of Activity and Calorimetricmentioning

confidence: 99%

Phase Equilibria in Binary Mixtures of Water with Triglyme and Tetraglyme: Experimental Determination and Thermodynamic Modeling

Kolín

Dohnal

2020

J. Chem. Eng. Data

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Because of their many favorable properties and specifically balanced amphiphilic nature, glymes (oligomeric ethylene glycol diethers) are of great technological and theoretical interest. This study focuses on the phase equilibria and energetics of aqueous solutions of two important members of the glyme series, triglyme (triethylene glycol dimethyl ether) and tetraglyme (tetraethylene glycol dimethyl ether). For these systems, we carried out accurate measurements of water activity at two temperatures (298.15 and 313.15 or 318.15 K) in the whole composition range, boiling temperatures at three pressures (50, 70, and 90 kPa), and freezing temperatures in the water-rich region. The melting temperature and melting enthalpy of the neat glymes were also determined. We correlated our water activity data simultaneously with some related thermal data from the literature using an extended SSF-type excess Gibbs energy (G E ) model. The established model descriptions provided not only particularly good fit of the underlying data but, as proven by due comparisons to other results from both the literature and this work, showed a superior performance, extrapolating very well to both higher and lower temperatures. The high-fidelity global modeling also enabled us to present a clear picture of the energetics of the two aqueous glymes. At near-ambient temperatures, both systems exhibit nonmonotonous activity coefficient courses with composition, large exothermic effects, and remarkably deep drops of the entropy accompanying the mixing, their positive G E being entropy-driven. On increasing the temperature, the former features gradually decline while G E keeps about the same magnitude and becomes enthalpy-driven. Although both systems show a great tendency to phase splitting above the normal boiling temperature of water, our model calculations predicted the lower critical solution temperature behavior only for the aqueous solution of triglyme. The observed pattern of the energetic behavior has been well elucidated in terms of competitive water−water and water−ether H-bonding.

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Effects of hydration on the thermodynamic properties of aqueous ethylene glycol ether solutions

Cited by 24 publications

References 40 publications

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their “True” Molecular Volume

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their “True” Molecular Volume

Dielectric Spectroscopy of Hydrogen Bond Dynamics and Microheterogenity of Water + Dioxane Mixtures

Phase Equilibria in Binary Mixtures of Water with Triglyme and Tetraglyme: Experimental Determination and Thermodynamic Modeling

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