Excess Thermodynamic Properties Research Articles

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.

Universality of grain boundary phases in fcc metals: Case study on high-angle [111] symmetric tilt grain boundaries

Grain boundaries often exhibit ordered atomic structures. Increasing amounts of evidence have been provided by transmission electron microscopy and atomistic computer simulations that different stable and metastable grain boundary structures can occur. Meanwhile, theories to treat them thermodynamically as grain boundary phases have been developed. Whereas atomic structures were identified at particular grain boundaries for particular materials, it remains an open question if these structures and their thermodynamic excess properties are material specific or generalizable to, e.g., all fcc metals. In order to elucidate that question, we use atomistic simulations with classical interatomic potentials to investigate a range of high-angle [111] symmetric tilt grain boundaries in Ni, Cu, Pd, Ag, Au, Al, and Pb. We could indeed find two families of grain boundary phases in all of the investigated grain boundaries, which cover most of the standard fcc materials. Where possible, we compared the atomic structures to atomic-resolution electron microscopy images and found that the structures match. This poses the question if the grain boundary phases are simply the result of sphere-packing geometry or if material-specific bonding physics play a role. We tested this using simple model pair potentials and found that medium-ranged interactions are required to reproduce the atomic structures, while the more realistic material models mostly affect the grain boundary (free) energy. In addition to the structural investigation, we also report the thermodynamic excess properties of the grain boundaries, explore how they influence the thermodynamic stability of the grain boundary phases, and detail the commonalities and differences between the materials.

Excess Thermodynamic Properties of Solutions in Ln-Ru (Ln = Nd, Gd, Dy) Binary Systems Based on Quadratic, Exponential and Combined Models Supported by Ab-Initio Calculations

Excess Thermodynamic Properties of Solutions in Ln-Ru (Ln = Nd, Gd, Dy) Binary Systems Based on Quadratic, Exponential and Combined Models Supported by Ab-Initio Calculations

Optical and thermodynamic studies on binary mixtures composed of two-isothiocyanato liquid crystals

Phase diagram and optical properties of the nematic mixtures containing two-isothiocyanatobenzen liquid crystal (7CHBT and 9CHBT) were studied by refractometry and DSC measurements. The thermodynamic and optical properties of the eutectic mixture (E79) composed of 7CHBT and 9CHBT were identified and studied. The phase diagram of the eutectic system was compared with the Schroder–van Laar calculation. The excess thermodynamic properties of the eutectic mixture were calculated and interpreted in terms of intermolecular interactions. The modified four-parameter model was used to fit the temperature dependence of the nematogen parameters on the refractive index. In addition, the temperature gradient of the ordinary refractive index (dno/dT) of the nematogens was analyzed in a convenient framework. The order parameters and polarizabilities of the nematic compounds, which are important parameters, were calculated through different methods based on birefringence measurements. Finally, the eutectic mixture and one of the constituent component (7CHBT) display crossover temperatures (TCO), which is very important liquid crystal parameter for specific applications such as optical devices and nonlinear optics.

Excess Thermodynamic Properties of Binary Mixtures of Dimethyl Malonate with some Branched Alkanols

The intermolecular hydrogen bond interactions in the dimethyl malonate with some branched alkanols (2-methyl-1-propanol, 2-propanol, and 2-butanol) binary mixture have been studied experimentally and theoretically. The ultrasonic velocities U, densities ρ of binary mixtures of dimethyl malonate with 2-methyl-1-propanol, 2-propanol, 2-butanol from 303.15 K to 318.15 K were measured. Excess molar volume (VE), deviation in adiabatic compressibility (Δβad) and excess intermolecular free length ( LEf) have been calculated from the measured experimental data. It is observed that the order of interactions in dimethyl malonate – branched alkanols mixtures is 2-methyl-1-propanol > 2-propanol > 2-butanol.

Binary Liquid Mixtures Nonanol and Decanol with their Thermodynamic and Transport Behavior: A Review

The extensive knowledge about structural phenomena of mixtures is of indispensable importance in the development of theories in liquid state. The information about structural and molecular interactions of liquid mixtures is quite vital from both fundamental and engineering point of view and can be utilized for further studies. For a better understanding of the non-ideal behavior of complex systems, fundamental thermodynamic and thermo-physical properties are the varied sources in which information is required. The excess thermodynamic properties are very sensitive to variables such as size, shape, composition, temperature and pressure, therefore an important information about the differences in the intermolecular interactions was obtained using these binary liquid mixtures under a range of physiochemical conditions. By using thermodynamics quantities, we can calculate the deviation of thermodynamics properties from those of an ideal mixture. These properties are necessary for the development of thermodynamic models required in optimized processes of the chemical, petrochemical, pharmaceutical and other industries. Along with diverse industrial applications, binary liquid mixtures can have hazardous effects such as pollutants causing air, water and soil contamination and some of them may have cancerous features. Their organic compounds and derivatives prepared from them are employed in a range of industrial and consumer applications such as perfumes, cosmetics, paints, varnishes, drugs, fuels, explosives, fats, dyes, waxes, resins, plastics, rubber, detergents, DDT etc. making them commercially important.

Structure-property relationships in actinide containing molten salts – A review: Understanding and modelling the chemistry of nuclear fuel salts

Molten salts have recently received increased attention worldwide as key materials for sustainable and low-carbon energy supply technologies (e.g. thermal energy storage, concentrated solar power technologies, fission and fusion nuclear reactors) thanks to their appealing thermo-physical properties. In particular, they are used as fuel and coolant in the Molten Salt Reactor (MSR), considered a breakthrough technology for the next generation of nuclear fission reactors. This review focuses on the thermochemical and thermo-physical properties of actinide bearing fluoride and chloride salts, used as nuclear fuel in MSRs, and more specifically on the structure–property relationships. In the last 15 years, the knowledge on the structural properties of actinide containing salts has grown quite significantly thanks to the development of dedicated high temperature in situ X-ray Absorption Spectroscopy measurements, and to the advancement of atomistic simulations. These have evidenced the formation of short-range order in the liquid, which contributes to storing energy in the salt and directly influences transport and thermodynamic excess properties. This interrelationship is illustrated in the present article, which covers both experimental and computational information, as well as most recent developments in the modelling methods at the mesoscale of the structural, thermodynamic, density and viscosity properties using the CALPHAD methodology.

Thermodynamic analysis of H2O − 3-aminopropyl tributyl phosphonium glycinate as a working pair for absorption refrigeration system

In this paper, A hydrophilic dual amino-functionalized ionic liquid 3-aminopropyl tributyl phosphonium glycinate ([aP4443][Gly]) with high thermal stability was used as absorbent and the refrigerant was water for the absorption refrigeration system (ARS). The heat capacities of the system were estimated by the differential scanning calorimetry (DSC) with various water mass fractions (w1) (0.004 to 0.6993) and temperatures (285 K to 365 K), and a polynomial equation on temperature and mass fraction of ionic liquid (w2) was associated. Between the experimental and estimated values, the average relative deviation (ARD) was 0.66%. The vapor–liquid equilibrium (VLE) data of the H2O–[aP4443][Gly] binary mixture was correlated using the electrolyte nonrandom two-liquid (eNRTL) model, and the binary mixture's excess thermodynamic properties were simulated. The first and second laws of thermodynamics were used to simulate the performance of a single-effect ARS with a solution heat exchanger (SHE). The ARS simulation results show that the coefficient of performance (COP) of the system with H2O–[aP4443][Gly] as the working pair is higher than that of the conventional working pair NH3-H2O but slightly lower than that of H2O-LiBr. Furthermore, the effect of generator temperature (Tg) on ARS is investigated; simulation results show that the ARS of the novel working pair has a higher COP value at higher generator temperature, indicating that H2O–[aP4443][Gly] has the potential to be a new type of absorption refrigeration working pair.

Thermodynamic Excess Properties of Binary Mixtures of Acetyl acetone and Ethyl Acetate

The density (ρ), viscosity (η), surface tension (σ), and refractive index (R) of binary mixtures of acetylacetone (acac) with ethyl acetate (Etac) were determined at atmospheric pressure over the entire composition range of mixtures. The values of mixtures and pure liquids have been used to calculate the excess volume (VE), deviation in viscosity (Δη), and deviation in surface tension. The computed results were fitted to the Redlich–Kister polynomial equation. The excess molar volume (VE) for the binary system investigated exhibits a positive deviation at 298.15 K, and the positive deviation at 303.15 K becomes too negative as the mole fraction Xacac increases. The deviation in viscosity (Δη) and deviation in surface tension (Δσ) show negative values from the ideality at 303.15 The negative magnitude suggests the presence of strong intermolecular interactions between unlike molecules in the binary mixtures.

Study on Interaction Capabilities of Ternary Liquid Mixtures by Thermodynamic Parameters at 308.15 K

Thermodynamic properties provide a deep and significant insight of the various interactions taking place multi component liquid mixtures especially in the field of petrochemical and reservoir engineering. The density, viscosity and ultrasonic velocity were measured experimentally for diethylmalonate (DEM) +1,4-dioxane with nitrobenzene (TM-1) and diethylmalonate (DEM) +1,4-dioxane + toluene (TM-2) at the temperature of 308.15K and atmospheric pressure over the entire range of mole fraction. The excess thermodynamic properties such as excess volume (VE), excess adiabatic compressibility (ΔKs), excess viscosity (Δɳ), excess free volume (ΔVF), excess free length (ΔLF), excess isothermal compressibility (ΔβΤ), were calculated from measured values and applied to Redlich - Kister polynomial equation to determine the appropriate coefficients. The excess or deviation properties were found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures. The deviations of the ternary mixtures from its ideal behaviour were determined in order to investigate the molecular interaction between the components of ternary liquid mixtures.

Molecular interaction studies based on thermophysical and excess thermodynamic properties of cinnamaldehyde with 1-butanol, isobutanol, 1-pentanol, isopentanol at different temperatures

In the present study, densities (ρ) and speeds of sound (u) of binary mixtures of trans-cinnamaldehyde (trans-CA) with 1-butanol (1-BuOH), isobutanol (i-BuOH), 1-pentanol (1-PtOH), isopentanol (i-PtOH) covering the entire composition range, at temperatures of (298.15, 303.15, 308.15 and 313.15) K and atmospheric pressure have been reported. Experimental densities and speeds of sound have been used to determine the excess volumes (VE), isentropic compressibilities (κS), excess isentropic compressibilities (κSE), excess speeds of sound (uE), excess intermolecular free length (LfE), and excess acoustic impedance (ZE) at four different temperatures. The values of VE and uE are found to be positive for all mixtures at each temperature studied. The value of κSE and LfE are negative over the wide range of composition for all the binary mixtures. The results have been used to understand the nature and extent of interactions like hydrogen bonding, dipole–dipole interactions, dispersive forces and interstitial accommodation ensuing between component molecules in the mixtures. Further, the investigated excess properties have been fitted by a Redlich-Kister equation to derive the adjustable parameters and the corresponding standard deviations are computed.