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Yizhak Marcus - One of the best experts on this subject based on the ideXlab platform.

  • relationships between the internal pressure the Cohesive Energy and the surface tension of liquids
    Physics and Chemistry of Liquids, 2017
    Co-Authors: Yizhak Marcus
    Abstract:

    ABSTRACTThe relationship between the internal pressure Pint on the one hand and the Cohesive Energy Density ced on the other and the ratio of the surface tension to the cube root of the molar volume σ/V1/3 (also called the Gordon parameter) was examined for a large number of liquids. These consisted of four classes: molecular liquids, liquid metals, room temperature ionic liquids (RTILs), and molten salts. Linear dependences, rather than proportionalities suggested by theory, were obtained in all cases, their slopes being independent of the type of the liquid (the exceptions being noted), but differ for Pint and ced.

  • the internal pressure and Cohesive Energy Density of liquid metallic elements
    International Journal of Thermophysics, 2017
    Co-Authors: Yizhak Marcus
    Abstract:

    The internal pressures, \(P_{\mathrm{int}}\), of practically all the liquid metallic elements in the periodic table up to plutonium (except highly radioactive ones) at their melting points were calculated from data in the literature. They are compared with the respective Cohesive Energy densities, ced, obtained from the literature data too. The ratios \(P_{\mathrm{int}}{/}ced\) for various liquids are ranked as follows: molten salts < polar/hydrogen-bonded molecular solvents \(\sim \) liquid metals < room temperature ionic liquids < nonpolar molecular solvents, and the reverse of this list reflects the relative strengths of the mutual interactions of the particles constituting these liquids.

  • the internal pressure and Cohesive Energy Density of two inorganic liquids bromine and carbon disulfide
    The Journal of Chemical Thermodynamics, 2016
    Co-Authors: Yizhak Marcus
    Abstract:

    The internal pressures, Pint, of two inorganic liquids: bromine and carbon disulfide were calculated from data in the literature and compared with their Cohesive Energy densities, ced. The values are in the ranges obtained for common organic liquids, but the ratio of ced/Pint for bromine is larger than might be expected for this non-polar but polarizable substance.

  • surface tension and Cohesive Energy Density of molten salts
    Thermochimica Acta, 2013
    Co-Authors: Yizhak Marcus
    Abstract:

    Abstract The surface tensions σ of a large number of molten salts are known as (decreasing) linear functions of the temperature. They may be compared at a so-called “corresponding temperature”, of which 1.1Tm is a good choice (Tm/K is the melting temperature). It is shown that for highly ionic molten salts of the 1:1, 1:2, and 2:1 charge types σ is a linear function of the Cohesive Energy Density, ced. Molten salts with pronounced partial covalent bonding have generally much smaller surface tension values than highly ionic ones having similar values of the ced. The correlation between σ and ced is rationalized and compared with correlations in the literature, but the latter pertain only to the alkali metal halides.

Andrew S Paluch - One of the best experts on this subject based on the ideXlab platform.

  • predicting limiting activity coefficients and phase behavior from molecular structure expanding mosced to alkanediols using group contribution methods and electronic structure calculations
    Journal of Chemical & Engineering Data, 2018
    Co-Authors: Pratik Dhakal, Sydnee N Roese, Maria A Lucas, Andrew S Paluch
    Abstract:

    The modified separation of Cohesive Energy Density (MOSCED) is a powerful tool for early stage process conceptualization and design. It is capable of making quantitative phase-equilibrium calculations, and more importantly may be used to qualitatively understand the underlying molecular level details of a system for intuitive process design. Unfortunately, its use is limited in that parameters must first be known before predictions may be made. Here we explore the use of group contribution methods (GC-MOSCED) and electronic structure calculations in the solvation model based on Density (SMD) and SM8 continuum solvation models to calculate missing parameters. We demonstrate the use of GC-MOSCED to expand MOSCED using limited data, and the ability of electronic structure calculations to calculate parameters devoid of experimental data. While GC-MOSCED performs best, we demonstrate that good predictions may be made using electronic structure calculations with the SMD continuum solvation model. Application is...

  • application of mosced to predict limiting activity coefficients hydration free energies henry s constants octanol water partition coefficients and isobaric azeotropic vapor liquid equilibrium
    Journal of Chemical & Engineering Data, 2018
    Co-Authors: Pratik Dhakal, Sydnee N Roese, Andrew S Paluch, Erin M Stalcup
    Abstract:

    Modified Separation of Cohesive Energy Density (MOSCED) is a solubility parameter-based method to predict limiting activity coefficients. In addition to making quantitative predictions, MOSCED may additionally be used to understand the underlying molecular-level driving forces for intuitive solvent selection and formulation. A major improvement of MOSCED over similar solubility parameter methods is that it splits the association term. We show by example how this change allows MOSCED to better model the molecular interactions of associating fluids. While parametrized to predict limiting activity coefficients, we demonstrate the ability to predict hydration-free energies, Henry’s constants in water, and octanol/water partition coefficients. We focus on water as MOSCED was previously found to perform substantially worse when water was the solvent. Comparison is made to molecular simulation and mod-UNIFAC, and we find for the studied reference set that predictions with MOSCED were in better agreement with exp...

  • Predicting Limiting Activity Coefficients and Phase Behavior from Molecular Structure: Expanding MOSCED to Alkanediols Using Group Contribution Methods and Electronic Structure Calculations
    2018
    Co-Authors: Pratik Dhakal, Sydnee N Roese, Maria A Lucas, Andrew S Paluch
    Abstract:

    The modified separation of Cohesive Energy Density (MOSCED) is a powerful tool for early stage process conceptualization and design. It is capable of making quantitative phase-equilibrium calculations, and more importantly may be used to qualitatively understand the underlying molecular level details of a system for intuitive process design. Unfortunately, its use is limited in that parameters must first be known before predictions may be made. Here we explore the use of group contribution methods (GC-MOSCED) and electronic structure calculations in the solvation model based on Density (SMD) and SM8 continuum solvation models to calculate missing parameters. We demonstrate the use of GC-MOSCED to expand MOSCED using limited data, and the ability of electronic structure calculations to calculate parameters devoid of experimental data. While GC-MOSCED performs best, we demonstrate that good predictions may be made using electronic structure calculations with the SMD continuum solvation model. Application is demonstrated for limiting activity coefficients and binary isobaric azeotropic vapor–liquid equilibrium with 1,2-ethanediol

  • developing a predictive form of mosced for nonelectrolyte solids using molecular simulation application to acetanilide acetaminophen and phenacetin
    Industrial & Engineering Chemistry Research, 2016
    Co-Authors: Ryan T Ley, Georgia B Fuerst, Bryce N Redeker, Andrew S Paluch
    Abstract:

    The Modified Separation of Cohesive Energy Density Model (MOSCED) is an efficient, analytic method to predict infinite dilution activity coefficients over a range of temperatures. Its predictability makes MOSCED an attractive engineering design tool. However, its use is limited. When trying to model a novel compound, reference data must first be available to regress the necessary MOSCED parameters. Here, we propose the use of molecular simulation to generate the reference dataset. In this fashion, MOSCED can be made a truly predictive engineering design tool. This combines the predictive strength of molecular simulation with the efficiency of MOSCED to create a powerful new tool. Here, we use molecular simulation to generate MOSCED parameters for the nonelectrolyte solid solutes acetanilide, acetaminophen, and phenacetin. Adopting the melting point temperature and enthalpy of fusion of these compounds from available experimental data, we are able to predict equilibrium solubilities. Predictions using the ...

  • Developing a Predictive Form of MOSCED for Nonelectrolyte Solids Using Molecular Simulation: Application to Acetanilide, Acetaminophen, and Phenacetin
    2016
    Co-Authors: Ryan T Ley, Georgia B Fuerst, Bryce N Redeker, Andrew S Paluch
    Abstract:

    The Modified Separation of Cohesive Energy Density Model (MOSCED) is an efficient, analytic method to predict infinite dilution activity coefficients over a range of temperatures. Its predictability makes MOSCED an attractive engineering design tool. However, its use is limited. When trying to model a novel compound, reference data must first be available to regress the necessary MOSCED parameters. Here, we propose the use of molecular simulation to generate the reference dataset. In this fashion, MOSCED can be made a truly predictive engineering design tool. This combines the predictive strength of molecular simulation with the efficiency of MOSCED to create a powerful new tool. Here, we use molecular simulation to generate MOSCED parameters for the nonelectrolyte solid solutes acetanilide, acetaminophen, and phenacetin. Adopting the melting point temperature and enthalpy of fusion of these compounds from available experimental data, we are able to predict equilibrium solubilities. Predictions using the new predictive MOSCED are in good agreement with available experimental solubility data for acetaminophen in nonaqueous solvents

Arvind Kumar - One of the best experts on this subject based on the ideXlab platform.

  • static dielectric constant of room temperature ionic liquids internal pressure and Cohesive Energy Density approach
    Journal of Physical Chemistry B, 2008
    Co-Authors: Tejwant Singh, Arvind Kumar
    Abstract:

    Measurements of the static dielectric constant (e) of ionic liquids (ILs) are very difficult because of the decay of field by the ionic conductivity of ILs. Herein, we describe an easy method for the prediction of e of various imidazolium-based ILs [Cnmim] from n, i.e. the ratio of internal pressure (Pi) and Cohesive Energy Density (ced). A calibration curve of n vs e for conventional organic solvents (mainly the linear alcohols) has been used to estimate the e of the ILs. Estimated e values for ILs having the anions [Cl]−, [BF4]−, [PF6]−, [TfO]−, and [Tf2N]− showed a very good comparison with the literature results, whereas ILs having the anions [CnOSO3]− tend to deviate from such correlation. Also, for a series of ILs having a common anion, the e is shown to follow a very good correlation with the molecular volumes. Predicted values show that both the nature of the anion and alkyl chain length of the cation contribute significantly to the e of the ILs. The method developed makes use of properties which ...

  • static dielectric constant of room temperature ionic liquids internal pressure and Cohesive Energy Density approach
    Journal of Physical Chemistry B, 2008
    Co-Authors: Tejwant Singh, Arvind Kumar
    Abstract:

    Measurements of the static dielectric constant (epsilon) of ionic liquids (ILs) are very difficult because of the decay of field by the ionic conductivity of ILs. Herein, we describe an easy method for the prediction of epsilon of various imidazolium-based ILs [C_n mim] from n, i.e. the ratio of internal pressure (P_i) and Cohesive Energy Density (ced). A calibration curve of n vs epsilon for conventional organic solvents (mainly the linear alcohols) has been used to estimate the epsilon of the ILs. Estimated epsilon values for ILs having the anions [Cl]-, [BF 4]-, [PF 6]-, [TfO]-, and [Tf 2N]- showed a very good comparison with the literature results, whereas ILs having the anions [C_n OSO3]- tend to deviate from such correlation. Also, for a series of ILs having a common anion, the epsilon is shown to follow a very good correlation with the molecular volumes. Predicted values show that both the nature of the anion and alkyl chain length of the cation contribute significantly to the epsilon of the ILs. The method developed makes use of properties which can be either experimentally determined or estimated with good accuracy and can be extended to the other categories of ILs with ease and reasonable accuracy.

Tejwant Singh - One of the best experts on this subject based on the ideXlab platform.

  • static dielectric constant of room temperature ionic liquids internal pressure and Cohesive Energy Density approach
    Journal of Physical Chemistry B, 2008
    Co-Authors: Tejwant Singh, Arvind Kumar
    Abstract:

    Measurements of the static dielectric constant (e) of ionic liquids (ILs) are very difficult because of the decay of field by the ionic conductivity of ILs. Herein, we describe an easy method for the prediction of e of various imidazolium-based ILs [Cnmim] from n, i.e. the ratio of internal pressure (Pi) and Cohesive Energy Density (ced). A calibration curve of n vs e for conventional organic solvents (mainly the linear alcohols) has been used to estimate the e of the ILs. Estimated e values for ILs having the anions [Cl]−, [BF4]−, [PF6]−, [TfO]−, and [Tf2N]− showed a very good comparison with the literature results, whereas ILs having the anions [CnOSO3]− tend to deviate from such correlation. Also, for a series of ILs having a common anion, the e is shown to follow a very good correlation with the molecular volumes. Predicted values show that both the nature of the anion and alkyl chain length of the cation contribute significantly to the e of the ILs. The method developed makes use of properties which ...

  • static dielectric constant of room temperature ionic liquids internal pressure and Cohesive Energy Density approach
    Journal of Physical Chemistry B, 2008
    Co-Authors: Tejwant Singh, Arvind Kumar
    Abstract:

    Measurements of the static dielectric constant (epsilon) of ionic liquids (ILs) are very difficult because of the decay of field by the ionic conductivity of ILs. Herein, we describe an easy method for the prediction of epsilon of various imidazolium-based ILs [C_n mim] from n, i.e. the ratio of internal pressure (P_i) and Cohesive Energy Density (ced). A calibration curve of n vs epsilon for conventional organic solvents (mainly the linear alcohols) has been used to estimate the epsilon of the ILs. Estimated epsilon values for ILs having the anions [Cl]-, [BF 4]-, [PF 6]-, [TfO]-, and [Tf 2N]- showed a very good comparison with the literature results, whereas ILs having the anions [C_n OSO3]- tend to deviate from such correlation. Also, for a series of ILs having a common anion, the epsilon is shown to follow a very good correlation with the molecular volumes. Predicted values show that both the nature of the anion and alkyl chain length of the cation contribute significantly to the epsilon of the ILs. The method developed makes use of properties which can be either experimentally determined or estimated with good accuracy and can be extended to the other categories of ILs with ease and reasonable accuracy.

Bryan B Sauer - One of the best experts on this subject based on the ideXlab platform.

  • the Cohesive Energy Density of polymers and its relationship to surface tension bulk thermodynamic properties and chain structure
    Journal of Applied Polymer Science, 2017
    Co-Authors: Bryan B Sauer
    Abstract:

    The Cohesive Energy Density (CED) and the internal pressure (Pi) have similar values for most liquids at low pressures. For most polymers CED cannot be directly measured, unlike Pi which is readily obtained in the melt from PVT or other related data. Directly measured CED are available for the oligomer linear alkane series over a moderate molecular weight (MW) range. Scaling CED with measured surface tensions (ɣ) leads to separation into two universal scaling curves, which provides a measure of surface configurational entropy, as does the MW dependence of experimental surface tensions for two polymer series. A novel polymer scaling curve based on CED is shown to provide improved accuracy in the prediction of ɣ for any polymer or solvent. For polymers that interact predominately through Van der Waals forces, correlations between the average interchain separation distances and the magnitude of CED (or Pi), are shown to give a universal derivation of CED. In contrast, polymers like P4VP having strong polar interactions provide dramatic evidence of the different physical basis of CED and Pi. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44431.

  • surface tension and melt Cohesive Energy Density of polymer melts including high melting and high glass transition polymers
    Macromolecules, 2002
    Co-Authors: Bryan B Sauer
    Abstract:

    Melt surface tensions and pressure−volume−temperature (PVT) data were obtained for many hydrophobic and hydrophilic polymers including high melting polyesters and polyamides such as poly(ethylene terephthalate) and nylon 66. A model is developed that uses surface tension to convert PVT data (from which the thermodynamic quantity “internal pressure” is calculated) into another thermodynamic bulk property, the Cohesive Energy Density (CED). The errors inherent in assuming that the CED has the same proportionality factor to internal pressure independent of chemical structure are discussed. The results emphasize the difference between internal pressure and CED, where only internal pressure can be directly obtained from PVT data. The CED is the quantity that must be used for calculations of surface tension, and examples of the determination of melt surface tension are given for several polar or hydrogen-bonding polymers and semicrystalline or amorphous polymers of different molecular weights. Poly(2-vinyl pyri...