Isobaric Expansion Research Articles

Volumetric properties of the water + tetramethylurea mixture over the temperature range from 274.15 to 333.15 K at atmospheric pressure

The densities of the binary mixture {water (1) + tetramethylurea (2)} have been measured in the entire composition range in the temperature range from 274.15 K to 333.15 K at atmosphere pressure. Excess molar volumes and molar isobaric thermal expansions of the mixture, apparent and partial molar volumes, partial molar isobaric expansions of water and tetramethylurea (TMU), including their limiting values, are calculated. It is shown that the formation of the water + tetramethylurea mixture occurs with a decrease in the volume of the mixture at all temperatures, and the partial molar volumes of water and TMU increase with increasing temperature. The temperature dependences of the limiting partial molar isobaric thermal expansions of both components are characterized by the presence of the extremum. The obtained results are discussed in terms of solute-solvent and solute-solute interactions.

Viscosity, Electrical Conductivity, Density and Surface Tension of Methyltriphenylphosphonium Carboxylate Ionic Liquids

Abstract In this paper, three new kinds of phosphonium-based room temperature ionic liquids (ILs) [Ph3PCH3][CH3(CH2)8COO] (MTPP-D), [Ph3PCH3][CH3(CH2)10COO] (MTPP-L), and [Ph3PCH3][CH3(CH2)12COO] (MTPP-M) were synthesized using triphenylphosphine, dimethyl carbonate and carboxylic acids as raw materials. The viscosity, electrical conductivity, density and surface tension of the synthesized ILs were measured in the temperature range from 298.15 K to 333.15 K under ambient pressure. Meanwhile, the effects of temperature and alkyl chain length on their viscosity, electrical conductivity, density and surface tension were also investigated. The molecular volume, standard entropy, lattice energy and isobaric expansivity of the three ILs were calculated at 298.15 K. Experimental results indicate that the viscosity, density and surface tension of the three ILs decrease significantly with the increase of temperature, while the electrical conductivity shows an opposite trend. The longer the alkyl chain, the higher the viscosity, the lower the electrical conductivity, density and surface tension of the ILs. The experimental dynamic viscosity can be well correlated by the Vogel-Fulcher-Tammann (VFT) equation and simple linear equation. The temperature dependence of electrical conductivity can be well fitted by Arrhenius equation and VFT equation. The molecular volume, standard entropy and isobaric expansivity increase with increasing alkyl chain length, while the lattice energy decreases.

Thermodynamics of binary mixtures 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (HFE-7200) + 2-propanol: High pressure density, speed of sound and derivative properties

Awareness about environmental impact of greenhouse gas emissions has lead to search for other alternatives which can cover the same utility range of wellknown CFCs, HCFCs and PFCs but without their undesirable effects on the planet. Since Hydrofluoroether fluids (HFEs) have emerged as a good alternative, it is necessary to characterize their thermophysical properties in order to bring reliable data to the industry. Density and speed of sound are two of the most important physical properties because of the amount of information that they provide in the design of the machinery involved in the utilization of these fluids as well as data for the parametrization of equations of state. This paper reports a set of new data concerning high pressure density, ρ, for the binary mixture x HFE-7200 + (1 − x) 2-propanol in a broad range of pressures (0.1–140 MPa), and at several temperatures (from 293.15 to 393.15 K). Density values were correlated by employing a Tait-like equation in the same p, T ranges, and the derivative properties, that is, the isothermal compressibility κT, and the isobaric expansion αP, were determined. Excess molar volumes VE, which bring information about the change in volume observed in the mixture were also calculated for the eight mole fractions investigated. Speeds of sound, c, at 0.1 MPa were measured experimentally in the temperature range (293.15–333.15 K). By using the Laplace equation, isentropic compressibilities, κS, were calculated from density and sound velocity values.

Ab initio inspection of thermophysical experiments for molybdenum near melting

We present quantum molecular dynamics calculations of thermophysical properties of solid and liquid molybdenum in the vicinity of melting. Detailed analysis of available experimental isobaric expansion data and extensive comparison over a wide set of properties with results of first-principle calculations is presented, possible reasons of contradictions are discussed. Accurate calculation of zero isobar confirms the density of solid Mo measured by electrostatic levitation technique and the lowest density of molten Mo observed in pulse heating experiments, that gives a substantial volume change on melting of about 5.5%.

Determination of the Temperature Dependence of the Isobaric Volumetric Expansion Coefficient for Certain Molecular Crystals of Nitro Compounds

This paper presents the form of the equations of state of molecular crystals of nitro compounds constructed on the basis of dividing Helmholtz free energy into an intramolecular and an intermolecular components. This division enabled us to determine the form of the Gruneisen equation for molecular crystals, the volume dependence of the Gruneisen coefficient, and the temperature dependence on the volumetric expansion coefficient. Comparative analysis of the calculated and experimental values of volumes of elementary cells of triaminotrinitrobenzene crystals depending on the temperature has shown their fair agreement.

Densities and Apparent Molar Volumes of Aqueous Solutions of K4Fe(CN)6, K3Fe(CN)6, K3Co(CN)6, K2Ni(CN)4, and KAg(CN)2 at 293 to 343 K

Densities of aqueous solutions of K4Fe(CN)6, K3Fe(CN)6, K3Co(CN)6, K2Ni(CN)4, and KAg(CN)2 have been measured with a vibrating-tube densimeter at temperatures from 293.15 to 343.15 at 5 K intervals over the approximate concentration range 0.02 to 0.4 mol·kg–1. Apparent molar volumes, Vϕ, calculated from these data were fitted with an extended form of the Redlich–Rosenfeld–Meyer equation to obtain the standard partial molar quantities, V°. The Vϕ and V° values for all the salts are in reasonable agreement with literature data at all temperatures. Deviations of the Vϕ values from the Debye–Huckel limiting law were found to increase considerably with increasing anion charge. Values of V° for the cyanometallate anions were obtained using an appropriate extrathermodynamic assumption and were found to increase with increasing crystallographic size or ionic charge except for Fe(CN)64–, which shows a remarkable contraction of more than 35 cm3·mol–1 relative to Fe(CN)63–. The origins of this anomaly are unclear. Isobaric expansivities, α, of all the salt solutions show the greatest increase with solute concentration, but the smallest dependence on the nature of the anion, at lower temperatures. These effects are consistent with the dissolved ions changing from water-structure breaking to net structure making with increasing temperature.

Limit of Relativistic Quantum Brayton Engine of Massless Boson Trapped 1 Dimensional Potential Well

A quantum Brayton engine using a massless Boson trapped in a one-dimensional potential well as a working substance has been constructed to be studied. We used a modified analogical model by the first law of thermodynamics for a quantum system implementation. The system was built with Klein Gordon equation, relativistic quantum mechanics Hamiltonian, without the mass term of the Hamiltonian and it was trapped in a one-dimensional potential well. Then, it underwent the quantum ideal Brayton cycle process. The quantum Brayton process consisted of adiabatic compression, isobaric expansion, adiabatic expansion, and isobaric compression processes. This relativistic quantum mechanics Brayton engine has found that the efficiency formulation was similar to the classical one. This study obtained the conformity results between the quantum relativistic and classical Brayton engines. By this cycle process, we also invented that the ratio of heat capacity under constant pressure and volume of the system was 2. It could indicate that the efficiency of quantum relativistic Brayton engine is higher than the classical one.

A volumetric and acoustic study of pseudo-binary mixtures of (water + 1,3-propanediol + 3-butoxypropan-1-amine) from T = (283.15 to 303.15) K

Due to the relevant role that polyols play either as solvents or additives in many industries thermodynamic properties of aqueous mixtures of these compounds have been largely studied. In this work we aim to study the effect of adding a small amount of 3-butoxypropan-1-amine on the volumetric properties of the binary (water + 1,3-propanediol) mixture. Densities and speeds of sound of the ternary (pseudo-binary) mixture, (water + 1,3-propanediol + 3-butoxypropan-1-amine), were measured at five different temperatures ranging from T = (283.15 to 303.15) K. Excess molar, volumes, isobaric expansions and isentropic compressions of the system, as well as the excess partial molar, volumes and isentropic compressions for water and 1,3-propanediol were derived. Some functions of transference of the 1,3-propanediol and water from the binary{water + 1,3-propanediol} to the ternary mixtures were estimated. The interpretation of the results was made in terms of changes in aggregation patterns and hydration.

The NADES glyceline as a potential Green Solvent: A comprehensive study of its thermophysical properties and effect of water inclusion

Abstract In this paper, two Natural Deep Eutectic Solvents, glyceline (Gly) and glyceline-water (GlyW), containing choline chloride as acceptor H-bond compound and glycerol as donor H-bond group are studied. For glyceline the mole relation is 1 (choline chloride): 2 (glycerol) and for glyceline-water the mole relation is 1 (choline chloride): 1.99 (glycerol): 1.02 water. The ternary NADES has been synthetized and characterized chemically by NMR techniques for this work. Several thermophysical properties in a wide range of temperature (278.15–338.15) K and at atmospheric pressure (0.1 MPa) have been measured for both compounds: density, ρ , speed of sound, u , refractive index, n D , surface tension, σ , isobaric molar heat capacity, C p , m , kinematic viscosity, ν , and electric conductivity, κ . Furthermore, some related properties have been also calculated: isobaric expansibility, α p , isentropic compressibility, κ S , molar refraction, R m , entropy and enthalpy of surface formationper unit surface area ( Δ S s and Δ H s ), and dynamic viscosity, η , and viscous flow and electrical conductivity activation energies. The results have been discussed in terms of the effect of temperature and the inclusion of water. We conclude that the compound containing water into the structure has a higher molar volume and a higher fluidity. The binary NADES (Gly) is a more structured liquid than ternary one (GlyW).

On the volumetric properties of 2-hydroxy ethylammonium formate ionic liquid under high-pressures: Measurement and molecular dynamics

This work aims to report not only the new measurement for densities of 2-hydroxy ethylammonium formate (2-HEAF) ionic liquid under high-pressures but also molecular dynamics considerations of nanoscopic characterization for physicochemical properties in the pressure range studied. High-pressure densities of 2-HEAF showed smooth trends with temperature and pressure variations. Measurements were carried out at temperatures T = (298.15 to 333.15) K and at pressures P = (0.1 to 40) MPa. The high-pressure densities of 2-HEAF have also been correlated by the use of Tait equation with AARD equal to 0.031% and the mechanical coefficients including the isothermal compressibility, isobaric expansivity and thermal pressure were estimated. Molecular dynamics simulations were carried out in the same pressure – temperature range as the experimental study. Force field was validated against experimental results and the microscopic structure was analyzed in terms of intermolecular interactions and their evolution with temperature and pressure.

Effect of temperature on thermodynamic properties of protic ionic liquids: 2-hydroxy ethylammonium lactate (2-HEAL) + short hydroxylic solvent

In this study, we have synthesized the protic ionic liquid 2-hydroxy ethylammonium lactate (2-HEAL), and investigated its volumetric and acoustic behaviour into different hydroxylic media (water, methanol and ethanol) at the temperature 288.15-323.15 K and atmospheric pressure. Total solubility of the ionic liquid into these solvents was observed at this range of temperature. Apparent molar volume and apparent molar isentropic compressibility values have been computed from the experimental data and fitted to a temperature dependent Redlich-Mayer equation. From these correlations, the limiting infinite dilution values of the apparent magnitudes have also been computed. Derived magnitudes such as isobaric expansibility and isothermal coefficient of pressure excess molar enthalpy were computed due to their importance in the study of specific molecular interactions among the ions and covalent molecules enclosed into mixtures. The measured experimental data were used to test the accuracy of prediction of different models (Mchaweh-Nasrifar–Moshfeghian model (MNM model) and the modified Heller temperature dependent equation (MHE) for density and Collision Factor Theory (CFT) for ultrasonic velocity). The obtained results indicate that ionic liquid interactions in water are weaker than in the studied alcoholic solutions, as previously observed in analogous protic ionic liquids.

Volumetric and ultrasonic studies on interactions of ethylene glycol, diethylene glycol and triethylene glycol in aqueous solutions of glycerol at temperatures T = (293.15 K − 308.15) K

Abstract Densities and ultrasonic speed of ethylene glycol, diethylene glycol and triethylene glycol in (0.00, 0.01, 0.03, 0.05) mol kg−1 aqueous solutions of glycerol have been measured at T = (293.15, 298.15, 303.15, 308.15) K and experimental pressure p = 0.1 MPa. From the density data, the apparent molar volume Vϕ, the partial molar volume V ϕ o and the partial molar volumes of transfer Δ V ϕ o have been calculated for glycols from water to aqueous glycerol solutions. Using ultrasonic speed values apparent molar isentropic compression Kϕ,s, partial molar isentropic compression K ϕ , s o and partial molar isentropic compression of transfer Δ K ϕ , s o , have been evaluated. The pair and triplet coefficients have been computed from partial molar volumes of transfer and partial molar isentropic compression of transfer. The apparent molar isobaric expansion at infinite dilution ( ∂ V ϕ 0 / ∂ T ) p , second order derivative ( ∂ 2 V ϕ 0 / ∂ T 2 ) p have also been calculated. The parameters thus obtained have been discussed in terms of (solute–solute)/(solute–solvent) interactions prevailing in the present ternary system along with structure making/structure breaking tendency of glycols in aqueous glycerol solutions.

Investigation of solutions of ethyl alcohol and the deep eutectic solvent of Reline for their volumetric properties

In this study, the deep eutectic solvent of choline chloride/urea, also known as Reline, was synthesized. Mixtures of Reline with ethanol were prepared covering the entire concentration range, and their densities were determined experimentally. Together with pure Reline and pure ethanol, this made a total of eleven systems, whose densities were measured over the temperature range of 293.15–333.15 K at pressure of 100 kPa. The volumetric properties of interest in the calculation of other derivative thermodynamic properties were determined for all of the investigated mixtures and temperatures. This included the correlation of density to temperature, as well as the excess molar volumes, partial molar volumes, partial molar volumes at infinite dilution, excess partial molar volumes, excess partial molar volumes at infinite dilution, and isobaric volume expansions. The excess molar volumes had negative values at all concentrations and temperatures. This led us to propose a possible molecular arrangement of the hydrogen bond network, placing Reline mainly in central positions, with the preference to be surrounded by ethanol molecules.

Study of Intermolecular Interactions of CTAB with Amino Acids at Different Temperatures: A Multi Technique Approach

Abstract The densities, ρ, viscosities, η and specific conductivities κ, of (0.0002, 0.0004, 0.0006 and 0.0008 m) CTAB in 0.1 m aqueous valine, leucine and isoleucine were measured at different temperatures. The measured data were used to calculate various useful thermodynamic parameters. A complete characterization of any mixture can be performed by means of these thermodynamic properties. The apparent molar volume, ϕv , partial molar volume, ϕ v 0 $\phi _v^0$ and partial molar isobaric expansibilities, ϕ E 0 , $\phi _E^0,$ were calculated using density data. The viscosity data were analyzed using Jones–Dole equation to obtain viscosity coefficients, A- and B-, free energy of activation per mole of solvent, Δμ 1°∗, and solute, Δμ 2°∗, enthalpy, ΔH ∗ and entropy, ΔS ∗ of activation of viscous flow. Measuring the changes in these properties has been found to be an excellent qualitative and quantitative way to obtain information regarding the molecular structure and intermolecular interactions occurring in these mixtures. Various structure-making/breaking ability of solute (cetyltrimethylammonium bromide) in presence of aqueous amino acid solutions were discussed. In addition, fluorescence study using pyrene as a photophysical probe has been carried out, the results of which support the conclusions obtained from other techniques.

Density and Speed-of-Sound Measurements for Dilute Binary Mixtures of Diethylammonium-Based Protic Ionic Liquids with Water

Physicochemical properties of diethylammonium (DEA)-based protic ionic liquids and their aqueous solutions were obtained using experimental measurements of density (ρ) at different temperatures from T = (293.15 to 313.15) K and the speed of sound (w) at 298.15 K. Four DEA-based protic ionic liquids (PILs) with carboxylates as anions were synthesized. The standard entropy (S0) and lattice potential energy (UPOT) for pure PILs were estimated from molecular volumes at 298.15 K obtained using experimental density data. Apparent molar volumes (ϕV), isobaric expansivity (α), isentropic compressibility (βS), and isothermal compressibility (βT) have been obtained for aqueous solutions of PILs using experimental density and speed-of-sound data. These data have been further used to understand the electrostriction and concentration dependence of internal pressure. The Passynski method has been used to estimate concentration-dependent hydration numbers of PILs. The results obtained have been discussed in terms of con...

Density, sound speed and derived thermophysical properties of n-nonane at temperatures between (283.15 and 473.15) K and at pressures up to 390 MPa

Abstract In this paper, we present density and speed-of-sound experimental measurements for n-nonane at temperatures between (283.15 and 473.15) K and pressures up to 68 MPa and 390 MPa respectively. The density measurements were performed with a vibrating-tube densimeter and the speed-of-sound measurements were carried out in a dual-path pulse-echo apparatus. The vibrating-tube densimeter was calibrated using pure helium and water over the full range of temperature and pressure investigated, while the speed-of-sound apparatus was calibrated using pure water at low pressure over the full range of temperature. The expanded relative uncertainties of the measurements were 0.08% for density and between (0.1 and 0.3)% for sound speed at 95% confidence. The density data were correlated with the modified Tait equation over the entire temperature and pressure range, with an absolute average relative deviation of 0.006%. An empirical equation was developed to represent the sound speed data with an absolute average relative deviation of 0.03%. Both sets of data were compared with the predictions from the equation of state developed by Lemmon and Span. Comparisons have also been made with the available literature and satisfactory agreement was found. Correlations were developed for the density and isobaric heat capacity of the liquid as functions of temperature at a reference pressure of 0.1 MPa, the latter based on literature data. Combining these correlations with the sound-speed surface, properties of the liquid were computed by thermodynamic integration up to a pressure of 390 MPa. Density, isobaric heat capacity, isothermal compressibility and isobaric expansivity values are reported, and their uncertainties were carefully investigated.

Densities and volumetric properties of (choline chloride + urea) deep eutectic solvent and methanol mixtures in the temperature range of 293.15–323.15 K

Abstract Deep Eutectic Solvents (DESs) have been introduced recently as a new generation of green solvents. DESs have great potential to be used in different fields and applications, and so, it is important to have information on the properties of DESs and their mixtures. Up to now, the volumetric properties of only aqueous mixtures of DESs have been investigated. In this study, we measured the densities of pseudo-binary mixtures of methanol and choline chloride + urea (1:2) (reline) at atmospheric pressure over the temperature range of 293.15–323.15 K. Based on the measured density data, excess molar volumes of the mixtures were calculated. All of the excess molar volumes had negative values, which show the stronger solvation interactions of the mixture molecules compared to the interactions within pure reline or methanol. Furthermore, the volumetric properties of partial molar volume, excess partial molar volume, partial molar volume at infinite dilution, excess partial molar volume at infinite dilution, and isobaric volume expansion were calculated. By comparing the excess partial molar volumes at infinite dilution of reline and methanol, it is concluded that each prefers to be surrounded by the other, and this tendency is stronger for reline molecules.

Interactions of Imidazolium Based Ionic Liquids with Water Studied by Density and Speed of Sound Measurements: Effect of the Chain Length of an Alkyl Substituent on the Imidazolium Ion

Densities and speeds of sound of three ionic liquids (ILs), 1-ethyl-3-methyl imidazoliumtetrafluoroborate (C2mimBF4), 1-butyl-3-methylimidazoliumtetrafluoroborate (C4mimBF4) and 1-hexyl-3-methylimidazoliumtetrafluoroborate (C6mimBF4) were measured in aqueous solutions at (288.15, 293.15, 298.15, 303.15 and 308.15) K. These data were used to calculate the volumetric properties apparent molar volume and apparent molar isentropic compression as a function of molality. Infinite dilution values for these properties were evaluated by an extrapolation procedure based on Redlich–Meyer type equations. Apparent molar isobaric expansions at infinite dilution were also obtained from the slopes of the apparent molar volume at infinite dilution versus temperature. All these properties are interpreted in terms of IL–water interactions. The hydrolysis of the \( {\text{BF}}_{4}^{ - } \) anion of the ILs and its effects on the results is discussed.

Consistent interpretation of experimental data for expanded liquid tungsten near the liquid-gas coexistence curve

We present quantum molecular dynamics calculations of thermodynamic properties of expanded liquid tungsten. Experiments on shock compression of porous tungsten and its subsequent expansion into different anvil materials are successfully reproduced. Special attention is paid to available isobaric expansion experimental data and theoretical estimations of the critical point. Density on our first-principles 1 kbar isobar of liquid tungsten is slightly higher than in most wire-explosion experiments and the slope of the isobar is more flat. The dependence of the specific enthalpy on temperature is in good agreement with dynamic heating experimental data. A special Monte Carlo analysis has been applied for the estimation of the liquid-gas coexistence curve and critical point parameters of tungsten. The result is close to an estimation obtained with Likalter's similarity relation.

Excess Partial Molar Enthalpies of 3-Ethoxypropan-1-amine and 3-Butoxypropan-1-amine in Water at 298.15 K

Direct excess partial molar enthalpies of the two alkoxyamines, 3-ethoxypropan-1-amine (EPA) and 3-butoxypropan-1-amine (BPA), in water at 298.15 K were obtained in the water-rich region at atmospheric pressure using a semiadiabatic isoperibol solution calorimeter. Derivatives of these partial molar properties with respect to the composition in these two systems and in this composition region were evaluated aiming to better scrutinize the molecular interactions and the effect of increasing chain length in this composition domain, where interesting features were pointed out by previous volumetric studies. The remarkable effect of hydrolysis in the excess partial molar enthalpies in the EPA system and the results obtained in the water-rich region for both systems complement the interpretations based on limiting partial molar, isobaric expansions and isentropic compressions previously obtained. Changes in aggregation patterns could also be identified.