Excess Thermodynamic Properties Research Articles

Temperature-dependent thermophysical characterisation of N,N-Dimethylbenzylamine binary mixtures with acetophenone derivatives (propiophenone, p-chloroacetophenone and p-methyl acetophenone)

ABSTRACT This study reports the density (ρ), speed of sound (u), and viscosity (η) of N,N-dimethyl benzyl amine (DMBA) binary mixtures with propiophenone, p-methylacetophenone, and p-chloroacetophenone in a temperature range of 303.15–313.15 K for various compositions. Excess thermodynamic properties (excess molar volume, V E ; excess isentropic compressibility, κ s E ; viscosity deviation, Δη; and excess Gibbs free energy of activation of viscous flow, ΔG *E ) were derived from the experimental data. The analysis focused on understanding intermolecular interactions, particularly the influence of the inductive effect on hydrogen bonding and dipole–dipole interactions within the mixtures. The Jouyban-Acree model was employed to predict the densities, speeds of sound, and viscosities. The model’s accuracy was assessed using the mean relative deviations (MRDs) and individual relative deviations (IRDs) between the calculated and experimental values. To further support these findings, Fourier Transform Infrared (FT-IR) spectroscopy was conducted to provide complementary insights into the intermolecular interactions within the mixtures.

Thermodynamic modeling of liquid binary alloys of the Al–Er system

The paper presents the results of a study of the thermochemical properties of the Al–Er system. The thermodynamic characteristics were evaluated (△fH0298, S0298, (H0298−H00), Cp(T) and Cp(liq)) for the intermetallic compounds Al3Er, Al2Er, AlEr, Al2Er3, AlEr2. The values of△fH0298 calculated based on the semiempirical Miedema model adapted for the group of Al–REM alloys were taken for calculations and amounted to –47.7, –58.4, –63, –55.2, –46.8 kJ/mol∙at, respectively. The mixing characteristics of liquid alloys of this system were evaluated by Terra software package for modeling the equilibrium states of heterogeneous inorganic systems with an extensive database of properties of individual substances. The model of ideal solutions of interaction products was used as a computational model. Modeling of equilibrium composition and properties of melts was carried out in the temperature range of 1900–2100 K, in an argon atmosphere at a total pressure of 0.1 MPa in the system. Comparison of the obtained results with the simulation results in the approximation of an ideal solution, allowed us to determine the excess integral thermodynamic properties of liquid alloys (Gibbs energy, enthalpy, and entropy). It is shown that in the studied temperature range, with an increase of temperature, there is a natural, though not significant, decrease in the values of these parameters by absolute value. It is established that the formation of liquid alloys of the Al–Er system is accompanied by significant heat release: the value of the integral enthalpy of mixing at a temperature T = 2100 K is –58.9 kJ/ mol∙at. When comparing the thermochemical properties of the Al–Er system with the binary systems Al–Y and Al–Sc studied by the same methods, it is shown that all energy curves pass through the extremum at XSc,Y,Er ≈ 0.5. The strongest interaction of the components is observed in the Al–Y system, (ΔHmix = –58.9 kJ/mol∙at), which is close enough to the maximum modulo value of the enthalpy of mixing in the Al–Er system. The weakest interaction is observed in the Al–Sc system (ΔHmix = –44.8 kJ/mol·at). The results obtained in this work provide a theoretical basis for further experimental study of erbium–containing aluminum alloys.

Excess Thermodynamic Properties and FTIR Studies of Binary Mixtures of Toluene with 2-Propanol or 2-Methyl-1-Propanol

Physical properties of the binary solutions, toluene with 2-propanol and 2-methyl-1-propanol, were measured at T = 293.15, 298.15, 303.15, 308.15, and 313.15 K and P = 100 kPa. The experimental density values were tested with the Emmerling et al. and Gonzalez-Olmos–Iglesias equations. The results indicate that the equation by Emmerling et al. is the best to correlate the density for toluene + 2-methyl-1-propanol system, while for toluene + 2-propanol, both proposed equations are proper to correlate the density with composition and temperature. The viscosity results were verified with different models containing two adjustable parameters. The values of viscosity deviation (∆η), excess molar volume (VE), excess Gibbs energy (ΔG*E), partial molar volumes (V1¯ and V2¯), and apparent molar volume (Vφ,1 and Vφ,2) were calculated. The values of the excess molar volume were positive for both systems, while negative values were obtained for the viscosity deviation and the excess Gibbs energy. The excess properties of the mixtures were adjusted to the Redlich–Kister equation. The values of thermodynamic functions of activation of viscous flow were computed and analyzed. Additionally, the Prigogine–Flory–Patterson (PFP) theory was applied to calculate VE and then compared with experimental values. The values of the percentage absolute average deviation obtained suggest the validity of this theory. The Fourier transform infrared spectroscopy (FTIR) spectra of the binary solutions studied in this work allowed for the understanding of the interactions between the molecules of these systems.

Experimental and computational insight in molecular interactions of imidazolium based deep eutectic solvent with selected alcohols (C1 and C2)

The experimental thermophysical properties (densities (ρ), speed of sound (u) and refractive (nD) indices) of binary mixtures containing 1:3 mol ratio of [1-butyl-3-dimethylimidazolium chloride to ethylene glycol] [BMIM]Cl: EG], deep eutectic solvent (DES), with selected alcohols (methanol and ethanol) were measured. The measurements of the binary mixtures and the pure solvents were conducted at temperatures ranging from (293.15 to 313.15) K in the interval of 5 K and at ambient pressure using an Anton Paar densitometer. Thermodynamic properties such as excess molar volumes (VmE), intermolecular free length (Lf), isentropic compressibilities (ks), deviation in isentropic compressibilities (Δks) and deviation in refractive indices (ΔnD) were computed from the measured data of physical properties. These excess thermodynamic properties are utilized to investigate the intermolecular interactions occurring between imidazolium DES and methanol or ethanol. Geometry optimization calculations were undertaken using Density Functional Theory (DFT) to model the structure of DES with a 1:1 mol ratio employing the B3LYP-D3 functional and a basis set of 6–31G++**. The DFT results revealed that the interaction energies within the DES in the presence of solvent favoured the formation of the complex. Furthermore, interrogation of the optimized structures at molecular level showed that the interactions were mediated by the electrostatic ionic bonding with the co-solvent playing a significant role in solubility. The excess molar volumes of binary mixtures were correlated using the Lorentz-Lorenz equation, and the densities and refractive indices were predicted using the Lorentz-Lorenz equation. The interaction energies and electrostatic interactions between the different solvents were predicted using quantum mechanics. The experimental data was found to be in good agreement with the theoretical data for the measured properties as well as the computational predictions of the stability of the systems.

Thermodynamic excess properties of the methyl tert-butyl ether + benzene + cyclohexane ternary system and its binary subsystems at temperature T = (293.15, 298.15, 303.15, and 313.15) K and ambient pressure

ABSTRACT This work reports for the first time, the experimental densities and sound speeds for the ternary system {methyl tert-butyl ether + benzene + cyclohexane} within the temperature range (293.15 to 313.15) K and under ambient pressure conditions. The related binary subsystems have also been reported. Experimental data were used to derive excess molar volumes and excess isentropic compressibilities. Redlich-Kister and Cibulka’s equations correlated the binary and ternary excess properties, respectively, with standard deviations falling below the estimated uncertainties of the corresponding properties. The results have been interpreted in terms of molecular interactions between mixtures’ components and structural effects. Additionally, two symmetric (Kohler and Muggianu) and two asymmetric (Hillert and Toop) binary contribution models have been tested for their ability to predict the excess properties of the ternary excess properties.

Pre-screening of an eco-friendly solvent for separating industrial mixtures: A useful tool for solvent selection

In this work, gas liquid chromatography was used to obtain the retention data of volatile organic solvents (here referred as solutes) at different temperatures, T = (313.15 - 353.15) K and at atmospheric pressure. The retention data obtained was used to compute the activity coefficients at infinite dilution. The solvent was prepared by the combination of 1‑butyl‑2,3-dimethylimidazolium chloride and diethylene glycol at 1:2 molar ratio and was used as a stationary phase to evaluate intermolecular interactions of various volatile organic solvents, including (aromatic hydrocarbons, ketones, alkanes, alkenes, alkynes, alcohols, thiophene, acetonitrile and tetrahydrofuran). Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were utilized to determine any possible shifts when the two compounds were assorted. TGA/DSC 1 was also utilized to determine the thermal stability of the investigated solvent and to confirm that there will be no bleeding on the column loading when operated at T = (313.15 - 353.15) K. The excess thermodynamic properties at infinite dilution including enthalpies, Gibbs free energies and entropy term were computed to further explain the types of interactions occurring between the systems. The activity coefficients at infinite dilution data were used to calculate the separation parameters (selectivity and capacity) to evaluate the feasibility of the solvent in separating the industrial mixtures. Values pertaining to selectiveness and capacity were evaluated and compared to other extracting solvents found in literature for the separation of azeotropic mixtures. The attained activity coefficients at infinite dilution data reveals that the investigated solvent better separate solutes at low temperatures and this is an added advantage when using 1‑butyl‑2,3-dimethylimidazolium chloride to diethylene glycol. In addition, the investigated solvent was found suitable for the extraction of azeotropic mixtures comprising alkanes and alcohols.

Improved solution thermodynamics modeling in pervaporation

The current work features a system-level design of pervaporation processes (typically utilized to break azeotropes) that is solution thermodynamics-based (inclusive of validated excess thermodynamic properties). Unlike the standard pervaporation modeling methodology in the literature, the current method (referred to here as PervapS3) deconstructs the membrane module into its constituent units, and the material and energy flows were mathematically validated. These amendments to the previous methodology (i.e., leaf-wise modeling, mathematical validation, and inclusion of excess thermodynamic properties) revealed significant deviations in key parameter values. For a given large-scale pervaporation process dehydrating aqueous isopropanol, the total membrane area and energy requirement calculated were up to 22% and 19% less than the values calculated using the previous methodology. Moreover, due to the inclusion of excess thermodynamic properties in the PervapS3 method, the minimum separation work and the second law (thermodynamic) efficiency were up to 94% and 78% less. In other words, the previous pervaporation modeling methodology overestimated membrane area, energy requirement, minimum separation work, and second law efficiency. Considering a conventional azeotropic distillation process for comparison with pervaporation, it was observed that the simulation-based distillation models from the literature were inclusive of the system non-idealities. Per the previous method, the non-ideal second law efficiency of azeotropic distillation would be compared against the ideal second law efficiency of pervaporation, overestimating the latter. The non-ideal second law efficiency must be employed to facilitate a fairer and more accurate comparison of disparate separation technologies.

Molecular interactions and thermodynamic modelling of N,N-dimethyl benzyl amine-alkoxy ethanol mixtures: an FT-IR spectroscopy and Jouyban–Acree model approach

ABSTRACT This study examines intermolecular interactions in binary mixtures of N,N-dimethyl benzyl amine (DMBA) with short-chain alkoxy ethanols (2-methoxy ethanol (ME), 2-ethoxy ethanol (EE) and 2-butoxy ethanol (BE)). Densities (ρ), speeds of sound (u) and viscosities (η) were measured from 303.15 K to 313.15 K at atmospheric pressure for all compositions. These data were used to determine excess thermodynamic and transport properties: excess molar volume (V E ), excess isentropic compressibility (κs E ), viscosity deviation (Δη) and excess Gibbs free energy of activation (ΔG *E ). Partial and infinite dilution molar partial properties were also calculated. Results focus on complex formation driven by chemical forces. The Jouyban–Acree model predicted these properties, with accuracy assessed using mean relative deviations (MRDs) and individual relative deviations (IRDs). FTIR spectroscopy provided additional insights into intermolecular interactions.

قياس ونمذجة الخواص الزائدة للمخاليط الثنائية والثلاثية من سيكلوهكسان و بيوتانول العادي 1-أوكتانول عند درجات حرارة مختلفة

This study aims to correlate the excess thermodynamic properties for new desirable mixtures. The density, refractive index, and viscosity of pure components and mixtures were measured over the entire composition range at atmospheric pressure and different temperatures. The results of measuring the density, viscosity, and refractive index were used to calculate the excess molar volumes, viscosity deviation, excess refractive index, and excess activation energies of viscous flow were reported for binary and ternary mixtures of cyclohexane, n-butanol, and 1-octanol at temperatures 20, 30, 40, and 50oC and over the whole mole fraction range. For all of the binary and ternary mixtures the computed excess molar volumes were correlated by applying the Redlich–Kister equation. and Prigogine–Flory–Patterson (PFP) theory. The correlations of excess molar volume, viscosity deviation, excess refractive index and excess activation energy to understand the effect of polar and nonpolar and temperature increase in the systems. Many works carried out to predict the excess thermodynamic properties, but the mixtures of this work have not been studied so far at such conditions. It is hoped that the present work will help in the availability of experimental data for some unknown mixtures to understand their behavior in the chemical processes, petrochemical industries and design processes. Keywords: Correlations, Excess properties, Density, Viscosity, cyclohexane and Alcohols, Binary and Ternary mixtures

Excess Thermodynamic Properties of Binary Liquid System Containing (Cyclic Ether + Octan-1-Ol) At Different Temperature

The ultrasonic velocity (u), density (ρ), and viscosity ( ) for the binary mixture 1,4-Dioxane (1) + Octan-1-ol (2) were measured over the whole composition range at temperature T = (298.15, 303.15 and 305.15) K. The experimental data have been used to calculate excess molar volume (VE), excess adiabatic compressibility ( ), excess viscosity ( ), excess intermolecular free length ( and excess internal pressure (PiE) over the entire composition range. These results have been fitted to the Redlich-Kister polynomial equation. Excess molar volume (VE), excess adiabatic compressibility ( ), excess viscosity ( ), excess intermolecular free length ( and excess internal pressure (PiE) were found to be negative for all temperatures. The results obtained have been discussed and interpreted in terms of the type and nature of the specific intermolecular interactions between the components.

A study on thermophysical properties of binary mixtures of n-hexane with benzene and some alkyl-substituted benzenes within temperature range (293.15–323.15) K: Experimental and modeling approach

The current work reports densities and sound speeds, and related thermodynamic excess properties, namely excess molar volumes and excess isentropic compressibilities, measured at temperatures from (293.15 to 323.15) K and under atmospheric pressure conditions for binary mixtures of n-hexane with benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Redlich-Kister polynomial correlated the thermodynamic excess properties to test the quality of experimental data. Excess properties contributed to understanding molecular interactions between involved molecules and the peculiarities of their packing in the mixture. The Jouyban-Acree model was used to correlate the mixtures' experimental densities, sound speeds, and their related derived properties, namely isobaric thermal expansivities and isentropic compressibilities. The average absolute percentage deviation of the correlated values from the experimental ones was better than 0.036 %, 0.058 %, 0.040 %, and 0.146 % for density, sound speed, isobaric thermal expansivity, and isentropic compressibility, respectively, attesting to the robustness of the Jouyban-Acree correlations. Additionally, the Perturbed Chain Statistical Associating Fluid Theory Equation of State modeled the densities of the current mixtures. Schaaff's Collision Factor Theory and Nomoto's relation were compared for their ability to model the sound speeds of the mixtures. The efficacy of these models was tested by computing the average absolute percentage deviations between experimental and computed values. The modeled densities are reasonably concordant with experimental data, with an overall deviation of 0.02 %. Notably, Nomoto's relation exhibited superior performance over Schaaff's theory in modeling sound speeds of current mixtures, with an overall deviation of 0.33 %. The current findings underline the efficacy and versatility of the used models for thermodynamic modeling in systems of varying complexity.

A simple model for density anomaly and excess thermodynamic properties of alcohol-like in water-like mixture

ABSTRACT Molecular dynamics simulations were employed to gain insights into the density anomaly and excess thermodynamic properties of a binary mixture composed of a solvent resembling water and a solute resembling alcohol. In our model, both fluids were represented by spherical particles interacting through effective potentials: a two-length scale potential for the solvent–solvent interaction while purely repulsive potentials were used for the solute–solute and solute–solvent interactions. The temperature of maximum density (TMD) present in the pure solvent system is also observed in our mixture. The TMD exhibits a positive deviation in the mixture when compared to the pure solvent fluid under high-pressure conditions, while it shows a negative deviation under low-pressure conditions what is consistent with experiments. The excess volume, enthalpy and isobaric heat capacity show extreme values at x ≈ 0.4 . Using the radial distribution function and the translational order parameter we suggest that this behaviour can be explained in terms of solute particles caged in solvent network.

FT-IR studies and excess thermodynamic properties of binary mixtures at various temperatures and correlation with the Jouyban–Acree model

ABSTRACT Densities (ρ), speeds of sound (u), and viscosities (η) for three binary mixtures of 4-Hydroxy-4-methyl-pentan-2-one with 3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol, and 1-amino propan-2-ol were calculated at temperatures ranging from 303.15 to 313.15 K and atmospheric pressure over the entire composition range. Experimental measurements were used to calculate the excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of the activation of viscous flow. Partial molar properties and infinite dilution molar partial properties are also calculated for each binary system. Heteroassociates molecules forming complexes and chemical forces with specific interactions can be discussed from the results. The Prigogine–Flory–Patterson theory is used to identify the most important interaction. The results of the Jouyban–Acree model are discussed in terms of the mean relative deviation and individual relative between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies confirm the experimental findings of the investigated mixtures.

FT-IR studies and excess thermodynamic properties of binary mixtures of propargyl alcohol and amino alcohols at different temperatures and correlation with the Jouyban–Acree model

ABSTRACT Densities (ρ), speeds of sound (u), and viscosities (η) for three binary mixtures of propargyl alcohol with 3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol, and 1-amino propan-2-ol were calculated at temperatures ranging from 303.15 to 313.15 K and atmospheric pressure over the entire composition range. Experimental measurements are used to calculate the excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of the activation of viscous flow. Partial molar properties and infinite dilution molar partial properties are also calculated for each binary system. The Prigogine-Flory-Patterson theory is used to identify the most important interaction. The results of the Jouyban-Acree model are discussed in terms of the mean relative deviation and individual relative between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies have also been added to confirm the experimental findings of the investigated mixtures.

Elucidation of hydrogen bond strength of benzylalcohol with alkyl Acetoacetates: The confirmation study by excess thermodynamic Properties, FTIR and DFT analysis

In this study, density of pure liquids and their binary mixtures of benzylalcohol (BA) with methyl acetoacetate (MAA), ethyl acetoacetate (EAA) and allyl acetoacetate (AAA) were measured experimentally at T=(298.15–313.15) K and P = 0.1 MPa by using Rudolph Research Analytical digital densitometer. Experimental data was correlate by applying Jouyban–Acree theoretical equation. Furthermore, the speed of sound of all studied pure and their binary solutions were measured at T= (298.15 and 308.15) K at atmospheric pressure at 2 MHz. The experimental density and speed of sound data further were used to calculate the excess molar volume (VmE), isentropic compressibility (κs), excess isentropic compressibility (κsE) and excess speed of sound (uE) at all compositions and temperature ranges. The calculated VmE, κsE, uE and experimental speed of sound were compared with theoretical models such as Redlich-Kister, Hwang, CFT and FLT equations. The obtained data were analyzed in terms of intermolecular interactions such as hydrogen bond formation between two atoms of benzylalcohol and acetoacetates. Among all the three systems, BA + MAA showed highest negative excess molar volume magnitude due to the change of molecular geometry through the keto-enol tautomerism. The negative magnitude of VmE data confirms the formation of H-bond between the –OH---O- groups of component molecules. Similarly, BA + EAA system showed highest negative magnitude of κSE owing to the more compressible than resultant ideal solutions. The deviation in κSE magnitude in binary systems due to the geometrical fitting and specific interactions in atoms of the benzylalcohol and acetoacetates. Furthermore, the existence of hydrogen bond and its strength in binary mixtures were confirmed by experimental FTIR spectroscopy and theoretical density functional theory (DFT) calculations.

Phase Equilibrium Properties of Binary Systems (Furfural + Ethanol or Butan-2-ol) at Several Temperatures

The vapor pressures of the binary mixtures (furfural + ethanol) and (furfural + butan-2-ol) along with the pure component ethanol were measured using the static apparatus for VLE measurements (static device) between temperatures of 283 and 363 K. The generated results from this work were correlated using semi-empirical correlations as described by the Antoine equation. The excess Gibbs function was computed at assorted constant temperatures and applied to fit a fourth-order Redlich–Kister equation utilizing the Barker’s technique, as these two systems in study exhibited positive deviations in GE at all temperatures studied over the whole composition range. The Modified UNIFAC (Do) model, UNIQUAC model, and the NRTL model together with the Peng-Robinson-Sheng-Lu equation of state (PRSL EoS) were also employed, and excellent results were observed in the modeling of the total pressure. The Redlich–Kister equation was applied successfully for modeling the thermodynamic excess properties.

Geometrical and temperature impact on elucidation of intermolecular interactions for the binary mixtures of morpholine with aliphatic esters by thermodynamic, FTIR and DFT study

Abstract In this investigation, the binary solutions of morpholine (MP) with tert-butyl acetate (TBA), iso-butyl acetate (IBA), butyl acetate (BA) and butyl acrylate (BAC) were prepared for the densities (ρ) and speeds of sound (u) measurements at T = (303.15, 308.15, 313.15 and 318.15) K over the entire composition range and at atmospheric pressure (P = 0.1 MPa). From these data, excess thermodynamic properties such as excess molar volume ( V m E ${V}_{m}^{E}$ ), excess isentropic compressibility ( κ S E ${\kappa }_{S}^{E}$ ) and excess speeds of sound ( u E ${u}^{E}$ ) were calculated to elucidate the strength and types of intermolecular interactions between the component molecules. Redlich-Kister (RK) equation and Prigogine–Flory–Patterson (PFP) theory was applied to correlate the excess parameters and excess volumes, respectively. Further, intermolecular free length theory and collision frequency theory were used to correlate the speed of sound data. Shifting of bands (δν), bond length and hydrogen bond strength between the atoms were calculated from the experimental FTIR and DFT theoretical studies. The systematic increasing order of the intermolecular hydrogen bond strength between the two atoms in the studied binary systems as follows: TBA > IBA > BA > BAC.

Separation Performance of Ethaline: Infinite Dilution Activity Coefficients and the Excess Thermodynamic Properties

Separation Performance of Ethaline: Infinite Dilution Activity Coefficients and the Excess Thermodynamic Properties

Thermodynamic Properties of Ethanol + Pyridine, Ethanol + Benzene, and Pyridine + Benzene Mixtures at Temperature 298.15 K and Under Atmospheric Pressure

Experimental densities, viscosities, refractive indices, and sound speeds at temperature 298.15 K and atmospheric pressure are reported for the binary liquid mixtures of ethanol + benzene, ethanol + pyridine, and benzene + pyridine. From these experimental data, various thermodynamic excess and deviation properties were calculated and fitted by the Redlich-Kister polynomial to determine the adjustable coefficients and the standard deviations. The number of Redlich-Kister coefficients for significantly representing each thermodynamic property was optimized by applying the F-test. The variation of thermodynamic excess and deviation properties with composition has been interpreted in terms of molecular interactions between components of the mixture and structural effects. Furthermore, several theoretical and semi-empirical models were used to predict the refractive indices and sound speeds of the investigated mixtures. The predicting ability of each model was ascertained in terms of mean absolute percentage deviation between experimental and calculated data.

Thermodynamic excess properties of binary mixtures of methanol + pyridine, methanol + benzene, and pyridine + benzene at several temperatures and atmospheric pressure

ABSTRACT This work reports experimental densities and sound speeds at (293.15, 298.15, 303.15, 308.15, and 313.15) K and viscosities at 298.15 K for the binary liquid mixtures methanol + pyridine, methanol + benzene, and pyridine + benzene over the entire range of compositions and atmospheric pressure. The excess properties, namely the excess molar volume , excess isentropic compressibility , and excess Gibbs energy for activation of viscous flow G* E were calculated from experimental data and are fitted to Redlich-Kister polynomials. The results obtained were discussed in terms of molecular interactions between the mixing components and structural effects.