Search

Ionic liquids have recently been of growing significance in pharmaceutical applications. The effect of some ionic liquids on the thermodynamic and transport characteristics of ceftriaxone sodium (CFNa) drug has been studied in this research. Density, speed of sound, and viscosity of CFNa in 1-butyl-4-methylpyridinium bromide, 1-hexyl-4-methylpyridinium bromide and 1-octyl-4-methylpyridinium bromide aqueous solutions have been measured at T /K = (288.15–308.15). Apparent molar volumes at infinite dilution, transfer apparent molar volume, apparent molar isentropic compressibility at infinite dilution and B and D viscosity coefficients of ceftriaxone sodium have been calculated and discussed with regards to solute-solute and solute-solvent interactions using experimental data. The apparent molar volumes and isentropic compressibility values in dilute region were acquired through fitting density and speed of sound data to Redlich-Mayer equation and the viscosity B and D coefficients values were given by Jones-Dole equation.

The values of density, ρ and speed of sound, u for the saccharides that are structural isomers i.e. D(+)-glucose and D(−)-fructose in (0.2, 0.4, 0.6, and 0.8) mol·kg−1 aqueous solutions of dipotassium oxalate (K2C2O4) at T = (288.15, 298.15, 308.15 and 318.15)K have been measured in the present work. Various volumetric parameters such as apparent molar volume (Vϕ), partial molar volume at infinite dilution ( V ϕ o ), transfer volume ( Δ V ϕ o ), have been derived from density records. Experimental values of the speed of sound were used to calculate ultrasonic parameters such as apparent molar isentropic compressibility ( K ϕ , s ), partial molar isentropic compressibility at infinite dilution ( K ϕ , s o ), and partial molar isentropic compressibility of transfer ( Δ K ϕ , s o ). The pair (VAB, KAB) and triplet interaction (VABB, KABB) coefficients have been calculated from transfer parameters by using McMillan-Mayer theory. The structure-making/structure-breaking affinity of the saccharides along with a detailed insight into the physicochemical interactions e.g. ion-hydrophilic, hydrophilic–hydrophilic and hydrophilic-hydrophobic interactions in the saccharide-salt system, have been retrieved through the scrutiny of these calculated parameters.

Physical properties, such as density (ρ) and speed of sound (u) of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 2-ethoxyethanol/2-propoxyethanol and their binary mixtures are measured over the whole composition range as a function of temperature between 298.15 K and 318.15 K at atmospheric pressure. Experimental values were used to calculate the excess molar volumes ( V m E ), excess values of partial molar volumes ( V ¯ m E ), excess values of isentropic compressibility ( κ s E ), free length ( L f E ), speeds of sound ( u E ) and isobaric thermal expansion coefficient ( α P E ) for the binary mixtures. These excess properties were fitted to the Redlich-Kister type equation to obtain the binary coefficients and the standard deviations. A qualitative analysis of these parameters indicates the interaction decreases with the increase in chain length. This was further supported by Prigogine–Flory–Patterson (PFP) theory of excess molar volume.

The densities and viscosities of binary mixtures monoethanolamine (MEA) + H2O, 2-(Diethylamino)ethanol (DEEA) + H2O, MEA + DEEA and ternary mixtures MEA + DEEA + H2O were measured over the entire composition at temperatures ranging from (293.15 to 333.15) K and atmospheric pressure. The volumetric and viscometric properties such as excess molar volume, partial molar volume, partial molar volume at infinite dilution, apparent molar volume, viscosity deviation, molar enthalpy, molar entropy and the molar Gibbs energy of activation for viscous flow of mixtures were calculated in terms of experimental data, respectively. Furthermore, excess molar volumes were fitted by the Redlich–Kister equation for binary mixture and by Cibulka equation for ternary solution. The volumetric and viscometric properties were analyzed through the molecular structure and intermolecular interactions.

The IL (ionic liquid) 1-(2-methoxyethyl)-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide [MOEMIM][NTf2] was prepared and confirmed by 1H NMR (1H nuclear magnetic resonance) spectroscopy and 13C NMR (13C nuclear magnetic resonance) spectroscopy. The density and surface tension for the binary mixtures of [MOEMIM][NTf2] with methanol and ethanol were measured across the entire range of mole fraction (x1 = 0.0000–1.0000) at T = (288.15–318.15) K. The average molar volumes of the binary mixtures were calculated from the experimental density, which increased with the increase of mole fraction and temperature. The excess molar volumes, VmE, were obtained and fitted by Redlich–Kister equation. The interaction between ionic liquid and alcohol is the strongest efficient packing and/or attractive interaction at the minimum point. The lower the temperature was, the smaller the absolute value of excess molar volume was. The new function – the molar surface quasi-Gibbs energy of mixtures was obtained by us in this work. On a basis of molar surface quasi-Gibbs energy of mixtures, a new Eӧtvӧs equation was obtained of mixtures and applied to binary mixtures of [MOEMIM][NTf2] with alcohols. The absolute value of the slope of the new Eotvos equation is the mole surface entropy, s, and the intercept is the molar surface enthalpy, h, which is temperature-independent. The deviation of molar surface quasi-Gibbs energy, Δgs, of mixtures for [MOEMIM][NTf2] with methanol and ethanol were calculated. Δgs was well fitted by Redlich–Kister equation. In terms of Redlich–Kister’s parameters, Ai, a new method for estimating the surface tension, γ, with any component of the mixtures is proposed and the estimated values, γ (est.), are in good agreement with the corresponding experimental ones, γ(exp.).

In this study, three mixtures of methylyltriphenylphosphonium bromide (MTPPB) as hydrogen bond acceptor (HBA) and N-methyl diethanolamine (MDEA) as hydrogen bond donor (HBD) component was used to prepare transition temperature mixtures (TTMs) into different mole ratios of 1:7, 1:10 and 1:16 HBA/HBD. Two important physicochemical properties of TTMs such as density and refractive index were investigated at the atmospheric pressure and temperature ranges of (293.15–353.15) K and (293.15–343.15) K, respectively. The experimental density data were used to derive the molar volume, molecular volume, lattice energy and isobaric thermal expansion coefficients. With the help of experimental refractive index data, the electronic polarization, molar refraction, and free volume were calculated at the whole temperatures. Several empirical equations were used to correlate refractive indices such as an empirical equation and one-parameter equations (Dale–Gladstone, Eykman, Lorentz–Lorenz, Newton, Arago–Biot, and Oster). Finally, the response surface methodology (RSM) was applied to evaluate the effects of two main factors such as temperature and mole ratio on the density and refractive index of TTMs. The results revealed that the molar ratio has almost a higher effect on the studied properties than temperature.

Today biofuels are emerging in an exponentially manner in order to replace the fossil fuels. Biofuels are composed of several organic compounds containing wide variety of functional groups. The interactions existing among these compounds play a significant role in the efficiency of the biofuels. In this paper, the authors presented the new findings related to interactions existing in ethylbutyrate and α, ω-alkanediols in pure state as well as in their mixtures. Densities and speeds of sound at various temperatures (298.15–323.15) K and at ambient pressure 0.1 MPa have been measured for these mixtures. From experimental data, the excess properties such as excess molar volume, V m E , excess isentropic compressibility, κ s E , excess molar isentropic compressibility, K s , m E , excess speed of sound, u E , and excess isobaric thermal expansion, α p E , of the investigated mixtures were calculated. All the excess parameter values were fitted using the Redlich-Kister polynomial smoothing equation. The results were analysed in terms of molecular interactions. The partial molar volumes, V ¯ m,1 and V ¯ m,2 , partial molar isentropic compressibilities, K ¯ s,m,1 and K ¯ s,m,2 , excess partial molar volumes, V ¯ m,1 E and V ¯ m,2 E and excess partial molar isentropic compressibilities, K ¯ s,m,1 E and K ¯ s,m,2 E over whole composition range; the excess partial molar quantities of the components at infinite dilution have been calculated. The variations of these parameters with change in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures. The V m E values for these mixtures were also calculated by using Prigogine–Flory–Patterson (PFP) theory and the results were compared with experimental findings.

The guanidinium-based ionic liquid (IL), 2,2-diethyl-1,1,3,3-tetramethylguanidinium bis(trifluoromethylsulfonyl)imide ([TMG(C2)2][NTf2]), was synthesized. Densities and viscosities of the IL and its mixtures with methanol or ethanol were reported at temperatures from 293.15 K to 323.15 K. The increment of IL concentration or the decrement of temperature significantly increases both density and viscosity. Excess molar volume (VmE) and viscosity deviation (Δη) of each binary mixture were calculated, and the Redlich–Kister equation was used to fit VmE and Δη with composition. When VmE is negative with the mole fraction of IL (x1) lower than 0.8 for two systems, Δη is negative over the whole concentration range. The positive VmE of the mixture at a high IL concentration indicates that interaction loss occurs. Moreover, structures of the equimolar mixture of IL and alcohol were obtained by DFT calculations, and alcohol–anion, alcohol–cation and cation–anion interactions were revealed. Strong H-bond interaction with the span of 1.61 A is formed between the H atom of the OH group in alcohol and the O atom in the [NTf2]− anion, while the O atom of the OH group in alcohol interacts with the methyl groups in the [TMG(C2)2]+ cation. Significant cation–anion interactions (

In this work, the experimental measurements for liquid densities of n-decane and m-xylene binary mixtures were performed over the entire composition range with a high-pressure vibrating-tube densimeter. The range of temperatures for the present measurements was from 293.15 K to 363.15 K and the pressures were up to 60 MPa. The combined expanded uncertainty of the density measurements is estimated to be 0.001ρ with 0.95 confidence. Experimental density values were correlated by the modified Tammann-Tait equation. The simplified Perturbed Associating Fluid Theory (sPC-SAFT) and Cubic Plus Associated (CPA) equations of state (EoS) were applied to predict the densities of n-decane and m-xylene and their mixtures. Reasonably results were observed between the experimental data and calculated results for the two equations, and the deviation is less than 0.48% and 0.89% with sPC-SAFT and CPA EoS, respectively. In addition, excess molar volumes were determined from the experimental density data as well as from sPC-SAFT and CPA models. The effects of pressure and temperature on the excess molar volume were also discussed.

New experimental data of density and viscosity for the binary mixtures of 1-butyl-3-methylimidazolium nitrate ([Bmim][NO3]) with + 2-propanol, 2-butanol and 2-pentanol are reported over the entire range of mole fraction at T = (293.15–323.15) K. To elucidate possible intermolecular interactions between the chemical species present in solutions, the excess molar volume, V m E thermal expansion coefficient, α excess thermal expansion coefficient, α E the isothermal coefficient of excess molar enthalpy, ∂ H m E / ∂ P T , x partial molar volume, V i ¯ and deviation in viscosity, Δ η were calculated. The excess molar volume of the binary mixture is negative over the entire mole fraction range and becomes more negative with increase in the temperature. Deviation in the viscosity is negative over the whole range of composition and decreases with increasing temperature. The obtained excess molar volume and deviation in viscosity were fitted to the Redlich–Kister polynomial equation. The experimental results have been discussed regarding molecular interactions and the formation of complex between unlike molecules. Influences of temperature and carbon chain length of alcohols were discussed.

Thermodynamic properties of calcium nitrate are of interest for development of thermodynamic databases, which can be applicable for thermal energy storage technologies. In the present work thermodynamic properties of Ca(NO3)2, i.e. heat capacity (Cp) and enthalpy of fusion, were determined experimentally. The enthalpy of fusion of Ca(NO3)2 (33.4 ± 1 kJ/mol) was measured in a closed Pt-crucible at the melting temperature 823 K for the first time. The heat capacity of Ca(NO3)2 was measured in the temperature range from 143 K to 723 K by three different differential scanning calorimeters. High temperature X-ray diffraction was used for determination of the temperature dependence of volume from 298 K to 723 K. Combination of heat capacity and volume allowed us to calculate the molar volume at 0 K and to obtain the thermal expansion. The Gruneisen parameter and bulk modulus were deduced from combination of the available ab initio values of Cv and the values of Cp as well as the thermal expansion obtained in this work. This methodology allowed us to perform a comprehensive analysis of experimental values and first principal calculations. A complete thermodynamic dataset for solid and liquid Ca(NO3)2 has been derived.

The densities and viscosities of binary solutions of (N-methyldiethanolamine + ethanol), (monoethanolamine + ethanol) and (N-methyldiethanolamine + monoethanolamine) as well as ternary solution of (N-methyldiethanolamine + monoethanolamine + ethanol) were measured at T = 293.15 K, 303.15 K, 313.15 K, 323.15 K. The volumetric and viscometric properties, such as the excess molar volume VE, the partial molar volume V ¯ , the partial molar volume at infinite dilution V ¯ ∞ and the viscosity deviation Δη, were calculated from the experimental densities and viscosities. The excess molar volumes and viscosity deviations of binary and ternary solutions were correlated by the Redlich-Kister equation and the Cibulka’s equation, respectively. The intermolecular interactions in binary and ternary solutions were analysed.

In this experimental, the densities of monoethanolamine (MEA) + alcohol binary mixtures were measured at temperatures from (293.15 to 333.15) K at 0.1 MPa. The studied alcohols include straight-chain ones, ethanol, n-propanol and n-butanol, and branched-chain ones, isopropanol, isobutanol and tertbutanol. From the experimental density values, we calculated the molar volume (Vm), the thermal expansion coefficient (αp) and excess molar volume ( V m E ). The V m E values for the six binary systems are all negative ranging from (−1.020 to −0.064) cm3·mol−1. For straight-chain alcohol mixtures, the V m E values follow the increasing order of ethanol V m E values follow the increasing sequence of tertbutanol V m E value for ethanol + MEA system is the most negative. Therefore, the formation of hydrogen bonds plays a leading role for excess molar volume in small molecule alcohol systems. On the other hand, for larger butanol molecule + MEA systems, steric effect leads to a decrease in excess molar volume with the increase in butanol molar volume. Furthermore, the V m E values were correlated with Redlich-Kister polynomial equation with the largest deviation of 0.048.

This article reports experimental densities ρ and speeds of sound (u) for the binary mixtures of di-n-butylamine and diisopropylamine with 2-butanol and 2-pentanol at a temperature range of (293.15–308.15) K with a temperature step of 5 K over entire composition range and at atmospheric pressure. Various thermodynamic parameters have been calculated using experimental data of densities and speeds of sound. The different parameters calculated are excess molar volume V m E , excess isentropic compressibilities κ s E , deviations in speed of sound u D , apparent molar volumes V ϕ , partial molar volumes V ¯ m , excess partial molar volumes V ¯ m E excess intermolecular free lengths L f E and excess acoustic impedance Z E . These parameters have been analysed in terms of nature and extent of intermolecular interactions. Effects of temperature, chain length and branching on intermolecular interactions have also been examined. Apart from this, FT-IR spectroscopy technique has also used to find more support for the results obtained from the calculated thermodynamic parameters. All the calculated properties have been correlated using Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard deviations.

Experimental measurements of densities and ultrasonic speeds for the binary mixtures of benzonitrile with methyl/ethyl/n-butyl methacrylates over the entire composition range were carried out in the temperature range 293.15 K–318.15 K and atmospheric pressure of 0.1 MPa. Using the experimental data, the excess molar volume, excess ultrasonic speed, excess isentropic compressibility, and excess molar isentropic compressibility have been calculated and correlated by Redlich-Kister equation. The partial molar and excess partial counterparts of molar volumes and molar compressibilities over the whole composition range; and at infinite dilution have also been calculated. The dependence of these parameters on composition and temperature has been interpreted in terms of intermolecular interactions prevailing in these mixtures. The order of interactions suggested by the excess functions is found to be MMA > EMA > BMA. The major cause of the order is the steric hindrance caused by alkyl group. The results showed the effect of varying chain length on excess functions and interactions of the system.

Over a full molar fraction range, for binary mixtures of x N-methylimidazole (hereafter abbreviated to N-mim) + (1 − x) water, +methanol, +ethanol, +1-propanol, +2-propanol, the mass density and sound velocity at (288.15, 298.15, 308.15, 318.15, 328.15) K, the mixing enthalpy at 298.15 K, and 1H NMR measurements, combined with the Ab initio calculations, have been carried out. The excess molar volume, excess average volume expansivity, excess sound velocity, excess isentropic compressibility, and the molar mixing enthalpy were calculated and fitted to a Redlich-Kister equation. The partial molar enthalpy of N-mim, the difference between the partial molar volume and the molar volume of N-mim, and the protons chemical shift changes were calculated and compared. The chemical shifts of N-mim protons, hydroxyl protons, and α-H (proton on the carbon atom next to the –OH group) of alcohols in the mixtures containing alcohols were explained by a model proposed by Gupta et al.. The properties indicate that the intermolecular interactions between unlike molecules are stronger than those between like molecules. An increase in temperature has a greater influence on the mixture containing water than on pure components, and has a greater influence on pure components than on mixtures containing alcohols. The predominant interactions between unlike molecules are hydrogen-bonded complexes in the mixture containing water, and are N-mim: alcohols = 1:1 hydrogen-bonded networks in the mixtures containing alcohols, where the alkyl groups of alcohols are electron-withdrawing groups, and the methyl group of N-mim is an electron-donating group. Ab initio calculations proved that the N⋯HO hydrogen bond in the mixtures is more stable and stronger than HO⋯HO in pure water or in pure alcohols and N⋯HC in pure N-mim. The strength sequence of the intermolecular interactions between unlike molecules for the mixtures at 298.15 K is N-mim–water > N-mim–methanol > N-mim–ethanol > N-mim–1-propanol ≥ N-mim–2-propanol.

Cholinium amino acids ([Ch][AA]) are novel, low toxic and biocompatible ionic liquids (ILs) which utilized widely in biotechnological processes. Since, the most of these processes were done in an aqueous media, it is vital to achieve better understanding of the interactions between ILs with other species in this media. In this respect, this work is focused on the investigation of physicochemical properties of the cholinium l -alaninate ([Ch][ l -Ala]) in water and in the presence of polyethylene glycol di-methyl ether 250 (PEGDME250) with different mass fractions 0.025–0.125 at T = (288.15–318.15) K under atmospheric pressure (≈85 kPa). Density ( ρ ), speed of sound (u), viscosity ( η ), and refractive index of the studied aqueous solutions were experimentally measured. The obtained values from the density and acoustic studies were used for calculating the limiting values for apparent molar volume ( V φ 0 ), apparent molar isentropic compressibility ( κ φ 0 ), and also the transfer molar volume ( Δ tran V φ 0 ) and isentropic compressibility ( Δ tran κ φ 0 ) of [Ch][ l -Ala] from water to aqueous PEGDME250 solutions. Also, viscosity A and B-coefficients were obtained from intercept and slope of the linear plot of viscosity data versus IL molarity. Moreover, the hydration number (nH) was computed from the isentropic compressibility and viscosity data. Finally, the solute-solvent interactions in the investigated solutions were evaluated on the basis of changing the above thermodynamic properties from aqueous binary to ternary solutions consist of the [Ch][ l -Ala] and PEGDME250. The results indicated that the IL-water interactions become stronger in the presence of PEGDME250 compared to pure water; and in above a critical concentration this ternary solution can be separated into two-phases.

Despite the importance of temperature-dependent density and viscosity data of ternary aqueous mixtures of DESs, experimental studies to determine these essential data have been rather limited. In the current study, the density and kinematic viscosity of the aqueous solutions of choline (chloride + glucose) DESs have been measured over the temperature range of (293.15–323.15) K and DESs concentration of about (1–10) mole%. Following the measurement of bubble temperature of the mixtures at 82.6 kPa, excess molar volumes, dynamic viscosities, viscosity deviations, and also activity coefficients of water in the mixture were calculated. In addition, suitable correlations have been proposed to represent the temperature and composition dependence of the density, kinematic viscosity and also dynamic viscosity data. All in all, the negative values of the excess molar volume, the positive values of dynamic viscosity deviation, alongside the activity coefficients with values less than unity denote negative deviation from ideality of the system studied. It was also observed that both the density and kinematic viscosity decrease with increasing temperature, while they tend to increase with higher mole fractions of DES.

In this work, the densities and refractive indices of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane with methoxybenzene, chlorobenzene, tert-butylbenzene and nitrobenzene at different temperatures T = (298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure using a DMA4500/RXA170 combined system were measured. Excess molar volumes, isobaric thermal expansion, molar refractions, and the deviations in refractive indices have been estimated. These parameters have been used to understand the interactions in the mixtures qualitatively. The values of excess molar volume were fitted to Redlich–Kister equation to check the accuracy of experimental data.

A microwave re-entrant cavity resonator apparatus was used for the determination of dielectric permittivity, mole fraction composition and molar density of two binary (CO + CO2) mixtures, with CO2 mole fractions of approximately 0.25 and 0.50. The dielectric permittivity was measured with a relative combined expanded uncertainty (k = 2) less than or equal to 0.13% over the temperature range from T = (255.05 to 313.28) K at pressures up to 8 MPa. The new dielectric permittivity data were used together with the pure fluid polarizability correlations to reduce the uncertainty in the mixture’s mole fraction composition by factor of 15 relative to that provided by the supplier. Moreover, by applying the Harvey-Prausnitz mixing rule, we determined the mixture molar densities from measured permittivities to within 0.53% (k = 2) in a previously unstudied region. The new mixture density data near 6 MPa agree within 1.4% of predictions made with the multi-parameter equation of state optimized for combustion gases (EOS-CG). Comparison of these data with the EOS-CG and literature density values show that mixture density determinations based on dielectric permittivity measurements and the Harvey-Prausnitz mixing rule can also be accurate for gas mixtures containing appreciable amounts of a polar substance.

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).

The density and surface tension for the binary mixtures of ionic liquid (IL) [C4py][DCA] with ethanol, 1-propanol and 2-propanol were measured across the entire range of mole fraction (x1 = 0.0000–1.0000) at T = (288.15–318.15) K. The average molar volume and the thermal expansion coefficient of the binary mixtures were calculated from the experimental density. The excess molar volumes, VE, of the binary mixtures were also calculated and well fitted by Redlich−Kister equation. The obtained VE are negative values over the whole composition range. The values of VE are related to the alcohol chain length and temperature. In order to predict the surface tension of the mixtures, the new function – the molar surface Gibbs energy of mixtures was obtained from Li’s model improved by us in this work. So, the molar surface Gibbs energy, gs, and its excess function, gsE, of mixtures for [C4py][DCA] with ethanol, 1-propanol and 2-propanol were calculated. The excess molar surface Gibbs energy, gsE, was well fitted by Redlich−Kister equation. In terms of the Redlich−Kister’s parameters, a new method for predicting the surface tension, γ, of the mixtures is proposed and the predicted values, γ (pre.), are in good agreement with the corresponding experimental ones, γ(exp.). On a basis of molar surface Gibbs energy of mixtures, a new Eӧtvӧs equation was obtained and applied to binary mixtures of [C4py][DCA] with alcohols. The absolute value of the slope of the new Eotvos equation is the mole surface entropy, s, and the intercept is the molar surface enthalpy, h, which is temperature-independent.

Density, ρ, speed of sound, u, and the difference in the temperature before and after the mixing process , ΔT, were measured for binary mixtures containing of cyclohexanol (CYC) + diethanolamine (DEA) or triethanolamine (TEA) or butylamine (BUT) or hexylamine (HEX) at (303.15–318.15) K except ΔT at 303.15 K. The excess molar volume, V m E , excess partial molar volume, V m , i E , excess thermal expansion coefficient, α E , isothermal coefficient of excess molar enthalpy, ( ∂ H m E ∂ P ) T , x , deviation in isentropic compressibility, Δ κ s , excess molar enthalpy, H m E , and excess partial molar enthalpy, H m , i E , were also calculated. The calculated data were satisfactorily correlated by Redlich – Kister equation. Some empirical models such as (Prigogine–Flory–Paterson) PFP, Wilson, (Non-Random Two Liquid) NRTL and (universal quasi chemical) UNIQUAC. Computational methods were performed using density function theory (DFT) and molecular dynamics (MD) simulation and were used to discuss and compare intramolecular and intermolecular interactions. An acceptable agreement was found between empirical and theoretical data.

Densities and viscosities of ternary system (1-pentanol + ethylcyclohexane + methyl myristate) and the corresponding binary systems, (1-pentanol + ethylcyclohexane), (1-pentanol + methyl myristate), and (ethylcyclohexane + methyl myristate) were determined at different temperatures from 293.15 to 323.15 K. The experimental data were further employed to calculate excess molar volume (VmE) and viscosity deviation (Δη). Over the whole composition range, the VmE values show positive deviations from ideal behavior and the Δη values are negative. The VmE values for the ternary mixtures were also correlated with the corresponding binary data using Cibulka and Redlich–Kister equations, respectively. The experimental data and results provide useful base data for further thermodynamic studies of alcohol–biodiesel–diesel blends.

Deep eutectic solvents (DESs) with propylene carbonate represent an appealing alternative for organic solvents and ionic liquids to dissolve lithium salts. The present research reports the effect of deep eutectic solvents {DESs (choline chloride/ethylene glycol with the molar ratio of 1.00:2.00) and (choline chloride/malonic acid with the molar ratio of 1.00:1.00) on the thermodynamic and transport properties of solutions of lithium nitrate (LiNO3) in propylene carbonate (PC). To evaluate solute–solvent interactions in the above systems first the volumetric, ultrasonic, and viscometric properties were studied. For this purpose, the density (d), speed of sound (C) and viscosity (η) were measured for the binary solutions of (LiNO3 + PC) and quaternary solutions containing (LiNO3 + PC) and DES in different mass fraction of, w = (0.05, 0.010, 0.015 and 0.020), at 298.15 K under ambient pressure. The measured data were used for calculation of the apparent molar volume (Vφ), standard partial molar volume (Vφ0), apparent molar isentropic compressibility (κϕ), partial molar isentropic compressibility (κφ0), partial molar volumes of transfer (ΔtrVφ0) and viscosity B-coefficient of (LiNO3 + PC + DES) solutions. Then, to evaluate the interaction energies, the density functional theory (DFT) of LiNO3 with DESs in PC has also been studied. The thermodynamic and transport investigations indicated that the choline chloride/ethylene glycol interactions are more favorable than choline chloride/malonic acid with LiNO3 in the presence of PC. Generally, the additions of these DESs on the solution of LiNO3 + PC lead to enhancing of the solute–solvent interactions. Also, the DFT results revealed that the interaction between the ChCl/EG with LiNO3 in PC is stronger than ChCl/MA with LiNO3 in PC confirming the result deduced from our experimental studies.

Different groups have important influence on the interaction between molecules. In order to understand the effect of group introduction on the molecular interaction in solution, the densities of six diluted solutions including three ionic liquids (ILs) and two organic solvents were measured. The groups include methylene and methyl. The three ILs are 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][NTf2]), 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmim][NTf2]), and 1-butyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmmim][NTf2]). The organic solvents are diethyl carbonate (DEC) and propylene glycol monomethyl ether (PEGMME). The measured densities were used to calculate apparent molar volumes, V ϕ / cm 3 · m o l - 1 , from 293.15 to 328.15 K with ± 0.02 K. Then, the fitting of infinite dilution apparent molar volumes, V ϕ 0 / cm 3 · m o l - 1 , were obtained by using the calculated values of apparent molar volumes. The effects of different structures of ILs cations and organic solvents on the apparent molar volume, infinite dilution apparent molar volume, limiting apparent molar expansibility and thermal expansibility coefficient were discussed.

Thermophysical properties for varying concentrations of essential (L-histidine) and non-essential (L-serine) amino acids in water and (0.05–0.15) mol kg−1 mixed aqueous diphenhydramine hydrochloride solvent system has been deliberated at different temperatures ranging (293.15−318.15) K and ambient pressure (101.3 kPa). The experimentally obtained data has been utilized to compute different volumetric, compressibility and rheological parameters such as apparent molar volume (Vϕ), partial molar volume (V0ф), partial molar expansibility (E0ϕ), apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression (K0ϕ,s), hydration number (nH), transfer parameters, viscosity coefficients etc. The structure breaking ability of the solute molecules has been comprehended using Hepler′s constant (temperature derivative of partial molar expansibility at constant pressure) and dB/dT (temperature derivative of viscosity B-coefficient) values. Further, by using the co-sphere overlap model various sorts of solute-drug interactions prevailing in the systems have been discussed.

The intermolecular interactions of glycerol with two polyethylene glycols i.e. polyethylene glycol 400 and polyethylene glycol 4000 in aqueous medium have been examined from the measurements of density and ultrasonic speed at temperatures T = (293.15, 298.15, 303.15, 308.15) K and experimental pressure p = 0.1 MPa. The apparent molar volume ( V ϕ ), partial molar volume ( V ϕ o ) and partial molar volume of transfer ( Δ V ϕ o ) have been evaluated from density data for polyethylene glycols from water to aqueous glycerol solutions. The limiting apparent molar expansibilities have also been evaluated. The ultrasonic speed measurements are used to determine apparent molar isentropic compression ( K ϕ , s ), partial molar isentropic compression ( K ϕ , s o ) and partial molar isentropic compression of transfer ( Δ K ϕ , s o ) for polyethylene glycols from water to aqueous glycerol solutions. From (partial molar volume and partial molar isentropic compression) of transfer, the pair and triplet coefficients are calculated. By the perusal of these determined parameters, the results have been explicated based upon the competing patterns of physicochemical interactions of co-solutes and the solvents.

The interaction of EG, DEG and TEG with biologically active D-Panthenol, as the function of temperature has been investigated by the combination of acoustic and volumetric methods. Speeds of sound and densities of EG, DEG and TEG in (0.05, 0.10 and 0.15) mol·kg−1 in aqueous solutions of D-Panthenol have been measured at T = (293.15, 298.15, 303.15 and 308.15) K. From the density data, the apparent molar volume ( V ϕ 0 ) and standard partial molar volume of transfer Δ V ϕ 0 for EG, DEG and TEG in aqueous D-Panthenol solutions have been determined. From the speed of sound data, the partial molar isentropic compression K ϕ , s and the partial molar isentropic compression of transfer Δ K ϕ , s 0 , have been determined. The pair and triplet interaction coefficient have also been estimated.

The density and viscosity measurements have been performed for the ternary ( dl -alanine/+ d (−)-fructose + water) system at T = 293.15, 298.15, 303.15, 308.15, 313.15 K and ambient pressure. By using the obtained experimental densities, the apparent molar volume, limiting partial molar volumes, limiting apparent molar volume of transfer, limiting apparent molar expansibility and hydration number are calculated for dl -alanine in the aqueous d (−)-fructose solution. Redlich-Mayer type equation has been applied for correlating the apparent molar volume values in dilute region. The obtained viscosity data in the whole concentration range were correlated to the Jones-Dole semi-empirical equation. The viscosity B-coefficients were obtained by fitting viscosity data to Jones-Dole equation. It is well established that the viscosity B-coefficient is a measure of solute–solvent interactions, and is directly dependent on the size, shape and charge of the solute molecules. With helping the obtained results from the volumetric and viscometric measurements, we are able to describe the nature of possible interactions in the studied ternary system.

The densities, ρ and ultrasonic speeds, u of binary mixtures of 2-diethylethanolamine (2-DEEA) with 1-propanol and 1-butanol, including those of pure liquids, are measured at 293.15, 303.15 and 313.15 K, over the entire composition range. From the experimental values of ρ and u, molar volume, V m , isentropic compressibility, κ s , acoustic impedance, Z , excess molar volume, V m E , excess ultrasonic velocity, u E , excess acoustic impedance, Z E , excess isentropic compressibility, κ S E and excess molar isentropic compressibility, K s , m E are calculated. Further, the partial molar isentropic compressibility K ¯ s , m , 1 and K ¯ s , m , 2 , and excess partial molar isentropic compressibility K ¯ s , m , 1 E and K ¯ s , m , 2 E over the entire composition range, the partial molar isentropic compressibility K ¯ s , m , 1 0 and K ¯ s , m , 2 0 , and excess partial molar isentropic compressibility K ¯ s , m , 1 0 E and K ¯ s , m , 2 0 E of the individual components at infinite dilution are also deduced. The variations of the consequent parameters indicate the presence of specific intermolecular interactions between the binary liquid systems. The infrared spectra are also recorded at room temperature (293.15 K).

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.

Isoniazid forms one of the most potent antitubercular drugs effective against M. tuberculosis which functions in combination with pyrazinamide, rifampicin and ethambutol drugs. A drug is subjected to many complex processes from the time it is administered to the time the biologic response is affected. The physical properties give an idea of various types of interactions taking place between drug and water molecule. Keeping this in mind we have measured densities (ρ) and speeds of sound (u) of Isoniazid (INH) in aqueous, aqueous sodium chloride and potassium chloride (0.06 mol·kg−1 and 0.1 mol·kg−1 in water) at three different temperatures i.e. T = (288.15, 298.15 and 308.15) K in the concentration range of (0.01 to 0.1) mol·kg−1. From these experimental data, apparent molar volume ( V ϕ ) of solute, isentropic compressibility ( κ s ) of solution, apparent molar isentropic compressibility ( κ ϕ ) of Isoniazid (INH) in water and in aqueous solutions of 0.06 and 0.1 mol·kg−1 sodium chloride and potassium chloride have been calculated. The limiting apparent molar expansivity ( E ϕ 0 ) of solute and coefficient of thermal expansion ( α ∗ ) of Isoniazid (INH) have also been calculated. Transfer parameters have been interpreted from the point of view of concentration dependence of solute–solvent interactions. Infinite dilution values of V ϕ and κ ϕ have also obtained from extrapolation to zero molality and have been utilized in obtaining transfer volumes ( Δ tr V ϕ 0 ) and transfer compressibility ( Δ tr κ ϕ 0 ) of Isoniazid (INH) from aqueous solutions of 0.06 mol·kg−1 and 0.1 mol·kg−1 sodium chloride and potassium chloride at different temperatures. Results are used to analyze the nature of solute-solvent, solute-solute interaction and structure making/breaking ability of solute in the aqueous solution.

In this work, the densities (ρ) were investigated for binary mixtures of ionic liquids (ILs) with molecular solvents, namely tributyl phosphate (TBP) and dimethyl carbonate (DMC), covering the entire concentrations over the temperature range from T = (293.15 to 323.15) K at 0.1 MPa. The involved ILs are 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([Bmim]Tf2N). From the experimental density values, molar volume (Vm), the thermal expansion coefficient ( α p ) and excess molar volume (VE) for binary mixtures were calculated. The VE values ranging from (−2.1040 to 0.417) cm3·mol−1 were interpreted in terms of intermolecular interactions and structural characteristics in the binary mixtures. For {[Bmim]PF6 + DMC, [Bmim]PF6 + TBP and [Bmim]BF4 + TBP} mixtures, the VE values are negative due to the dominant electrostatic attraction between cation and anion in IL and hydrogen bonding between IL and TBP/DMC. While for the large molecular system, {[Bmim]Tf2N + TBP}, steric hindrance leads to VE values changing from negative to positive with the increasing of IL concentration. Additionally, the VE values were correlated with Redlich-Kister polynomial equation.

Thermodynamic properties of l -Alanine and l -Valine in aqueous solutions of drug dolonex, have been investigated by combination of volumetric and acoustic methods at various temperatures (293.15, 298.15, 303.15, 308.15 and 313.15) K and at atmospheric pressure. The experimental data is further used to calculate limiting apparent molar volume, VoΦ, limiting apparent molar volume of transfer, VoΦ,tr, limiting molar isentropic compression, KoΦ,S and limiting apparent molar isentropic compression of transfer, KoΦ,S,tr. Furthermore, apparent molar expansivity, EoΦ, Hepler constant values, ∂ E Φ o ∂ T P , coefficient of thermal expansion, α and hydration number, nH were also calculated. The obtained results were used to interpret solute-solute and solute-solvent interactions in these systems. The volumetric and compressibility data suggests dominance of hydrophilic-hydrophilic interactions in these systems.

Densities (ρ), speeds of sound (u) and viscosities (η) for binary mixtures of {water + ethanol, or + ethylene glycol (EG), or + diethylene glycol (DEG), or + triethylene glycol (TEG), or + polyethylene glycol (PEG) 200, or + polyethylene glycol (PEG) 300, or + polyethylene glycol (PEG) 400, or + polyethylene glycol (PEG) 600, or + glycerol} have been determined as a function of composition at T = (293.15, 298.15, 303.15 and 308.15 K) and atmospheric pressure. From these results, excess molar volume ( V m E ), deviation in isentropic compressibility (ΔκS), deviation in viscosity (Δη), and excess Gibbs energy of activation for viscous flow (ΔG∗E) were calculated and fitted by the Myers-Scott equation, as a function of mole fraction. Values of V m E and ΔκS were negative over the entire composition range for all mixtures studied. The values of Δη were negative for the systems containing ethylene glycol and glycerol and positive for the systems containing ethanol, PEG 400 and PEG 600. For other systems, the deviation of viscosity presented an S-shape, with negative values at high water concentration. For all mixtures studied, the values of ΔG∗E were positive over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.

In the present work there are reported thermophysical properties measurements: densities, speeds of sound, and refractive indices for four binary mixtures namely {dimethylsulfoxide (DMSO) + methylethanolamine (MEA), or benzyl amine (BLA), or 3-dimethylaminol-1-propanol (DMAP), or 2-[2-(dimethylamino-ethoxy-ethanol)] (DMAEOE)} over the entire composition range and at temperatures range of (293.15–323.15) K and at pressure p = 0.1 MPa. From these experimental results, excess/derived properties: excess molar volume, isentropic compressibility, deviation in isentropic compressibility and deviation in refractive index have been calculated. Excess/derived properties have been correlated using the Redlich–Kister equation. The results obtained from the work have been discussed in terms of the nature of molecular interactions between the components of the mixture.

L -carnitine plays physiologically important roles specifically to decrease triglycerides, very low density lipoprotein (VLDL) and cholesterol. Considering these facts, it is believed to be helpful in the reduction of cardiovascular diseases and diabetes. Physicochemical properties of L -carnitine in aqueous or mixed aqueous solutions are scarcely available in literature. Such properties will be useful in understanding the interactions of L -carnitine with other cellular components like trimethylamine-N-oxide (TMAO), dextrose ( D -glucose) and NaCl. The values of densities (ρ) and speeds of sound (u) of L -carnitine were measured over the molality range of m = 0.05 mol·kg−1 to m = 0.3 mol·kg−1 at temperature T = 293.15 K to T = 313.15 K in water and in aqueous solutions of TMAO, dextrose, and NaCl. Using these data, values of apparent molar volume (V2,m,φ) and apparent molar adiabatic compressibility (Ks,2,m,φ) have been determined. The results obtained from these measurements have been used to derive the standard partial molar volume ( V 2 , m o ), standard partial molar adiabatic compressibility ( K s , 2 , m o ), standard partial molar volume of transfer ( Δ tr V 2 , m o ) and standard partial molar isentropic compressibilities of transfer ( Δ tr K S , 2 , m o ) from water to aqueous solutions of TMAO, dextrose, and NaCl. Through Isothermal Titration Calorimetry (ITC), the enthalpies of dilution ( Δ dil H m ) of L -carnitine in water (over a temperature range of T = 293.15 K to T = 313.15 K) and in aqueous solutions of TMAO, dextrose, and NaCl have been determined. The values of standard molar enthalpy of dilution ( Δ dil H m o ) and their transfer values ( Δ tr Δ dil H m o ) have been derived from these measurements. The results have been discussed in terms of possible intermolecular interactions. The data suggest that there is overall balancing of hydrophobic and hydrophilic interactions in system containing L -carnitine and TMAO in aqueous solution, but hydrophobic effect dominates when the co-solute is NaCl or dextrose.

A calorimetric and thermodynamic study of the (Li1-xNax)FeGe2O6 solid solution with the pyroxene structure was undertaken. The molar heat capacity at constant pressure (Cp,m) for compositions with x = (0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0) was measured using a Physical Properties Measurement System at temperatures from 2 K to 300 K and by differential scanning calorimetry between 282 and 870 K (these measurements were performed upon heating as well as upon cooling). Magnetic transitions below 20 K and structural P21/c ↔ C2/c phase transitions at higher temperatures were observed that decrease in temperature with increasing Na/(Na + Li). The P21/c ↔ C2/c transition showed a considerable temperature hysteresis that is largest for LiFeGe2O6 (∼30 K) and decreases with increasing Na/(Na + Li) in the pyroxene. The molar enthalpy and entropy changes associated with the P21/c ↔ C2/c phase transitions, ΔHtr,m and ΔStr,m, were determined. They can be described by quadratic and linear functions across the solid solution. A linear correlation between ΔHtr,m and the square of the volume strain at the transition temperature was established. The P21/c ↔ C2/c phase transition of LiFeGe2O6 is compared to that of α-β quartz, whose Cp,m was also measured. The molar enthalpy of order, ΔHord,m, was calculated from the calorimetric data. It has a maximum of ΔHord,m = (−11.6 ± 1.5)kJ·mol−1 for the P21/c ↔ C2/c phase transition of LiFeGe2O6, which is in reasonable agreement with a maximum ΔHord,m = −9.9 kJ·mol−1 calculated using density functional theory. ΔHord,m vs. T behavior was described using a tricritical Landau model with an a parameter of a = (41.8 ± 1.0)J·K−1·mol−1. All properties associated with the P21/c ↔ C2/c phase transition in LiFeGe2O6 can be calculated using this value. The Cp,m behavior at T 0.4 have the P21/c ↔ C2/c phase transition below 298.15 K, this results in a discontinuity in Scal,m298.15 behavior as function of composition at Na/(Na + Li) = 0.5. DQF was applied to model this behavior and the corresponding parameters were retrieved. The entropy of mixing behavior of the (Li,Na)FeGe2O6 solid solution at 298.15 K is characterized by positive excess molar magnetic entropies of mixing onto which entropy changes due to the structural P21/c ↔ C2/c phase transitions are superimposed in the Na-rich part of the binary system. Excess volumes of mixing for the (Li,Na)FeGe2O6 solid solution were calculated from published data and DQF parameters were derived that allow volume as function of temperature and composition to be calculated. The molar third law entropies at T = 298.15 K are Som = (188.3 ± 2)J·K−1·mol−1 and Som = (203.1 ± 2)J·K−1·mol−1 and the molar enthalpies of formation from the elements at T = 298.15 K are ΔfHom = (−1817.2 ± 9)kJ·mol−1 and ΔfHom = (−1834.0 ± 9)kJ·mol−1 for the end members LiFeGe2O6 and NaFeGe2O6, respectively. ΔfHom was calculated using density functional theory (DFT). Values for ΔfHom, Som, and molar volume, for the coefficients of Cp,m polynomials, for thermal expansion and for the bulk modulus of the end members were compiled and can be used, in combination with the derived volumetric and entropic mixing properties, for phase diagram calculations involving the (Li,Na)FeGe2O6 solid solution.

Densities of aqueous solutions of lithium tetraborate in the (0.01 to 0.12) mol·kg−1 concentration range at a 5 K intervals from 283.15 K to 363.15 K and 101.325 kPa were measured using a precise Anton Paar Digital vibrating-tube densimeter. Apparent molar volumes are obtained on the basis of experimental density data, and then the 3D diagram of (mi, T, Vϕ) apparent molar volumes against temperature and molality were plotted. On the basis of Pitzer ion-interaction equation of the apparent molar volume model, the Pitzer single-salt parameters ( β M,X ( 0 ) v , β M,X ( 1 ) v ), β M,X ( 2 ) v and C M,X ( v ) ), and their temperature-dependence correlation F(i, p, T) = a1 + a2T + a3T2 + a4/T + a5ln(T) + a6/(T−263) + a7/(680−T) (where T is temperature in Kelvin, p is a pressure in 101.325 kPa, ai are model parameters) for Li2B4O7 are obtained, which is not reported in the literature. The deviations of the experimental and calculated values of Pitzer single-salt parameters β M,X ( 0 ) v , β M,X ( 1 ) v , β M,X ( 2 ) v and C M,X ( v ) for Li2B4O7 are all within ±0.1, and those results indicate that the single salt parameters and their relational coefficients of temperature-dependence for Li2B4O7 obtained in this work are reliable.

Density and sound velocity of the solutions of ionic liquids based on N-alkyl-N-methyl- morpholinium cations: N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-octyl-N-methyl -morpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide in N,N-dimethylformamide and N,N-dimethylacetamide were measured at T = (298.15–318.15) K and at atmospheric pressure. Using experimental data, apparent molar volume and apparent molar compressibility values were calculated and fitted to the Redlich-Meyer type equation which was used to obtain partial molar volume and partial molar isentropic compressibility of the ILs at infinite dilution. By using the density data, the isobaric thermal expansibility coefficients were also estimated. The effect of alkyl chain length of the ILs, experimental temperature and properties of solvent on these thermodynamic properties were discussed.

The effect of (D−)-fructose (fruit sugar), (D+)-galactose and (D+)-lactose (milk sugar) on the solute–solvent interactions occurred between the diphenhydramine-hydrochloride (DPH-HCl) drug and water was studied. To this end, the density, speed of sound and viscosity data for DPH-HCl drug in water and aqueous solutions of (D−)-fructose, (D+)-galactose and (D+)-lactose should have been measured. Thermodynamic properties such as the apparent molar volume (Vϕ) and apparent molar isentropic compression (Ks,m) were calculated from the density and speed of sound values within sugar molality range of (0.05, 0.1, and 0.15) mol kg−1 at T = (288.15, 293.15, 298.15, 308.15 and 318.15) K. Extrapolation to the infinite dilution of Vϕ and Ks,m values with using Redlich–Meyer equation was applied to find the corresponding limiting apparent molar quantities. Jones–Dole equation was used to obtain the viscosity B-coefficients. Interparticle interactions occurred between the DPH-HCl drug and water were determined by calculating the transfer parameters of limiting apparent molar volume and viscosity B-coefficient from DPH-HCl in water to the DPH-HCl in aqueous (D−)-fructose, (D+)-galactose and (D+)-lactose solutions.

The transition-temperature mixture (TTM) is a new type of solvent and is known as a tuneable solvent similar to deep eutectic solvent (DES). The new type of solvent called ternary transition-temperature mixture (TTTM) was prepared to use for CO2 capture purposes. In this work, TTMs and TTTMs were prepared with potassium carbonate (PC) as a hydrogen bond acceptor (HBA) and three hydrogen bond donors (HBDs) such as glycerol (GL), ethylene glycol (EG) and 2-amino-2-methyl-1-3-propanediol (AMPD) known as a hindered amine (HA). Binary TTMs were PC-GL with mole ratios 1:10 and 1:16 and PC-EG with the same mole ratios. TTTMs were prepared by adding AMPD in binary TTMs such as PC-GL-AMPD 1:16:1 and PC-EG-AMPD 1:10:1. The experimental density and refractive index of all mixtures were measured at temperatures from 293.15 K to 343.15 K with an interval of 5 K. The effect of temperature, mole ratio, molar massand alkyl chain length on the properties was investigated. The molar volumes and isobaric thermal expansion were calculated using experimental density data. The experimental refractive index values were used to derive the specific refraction, molar refraction, free molar volume, electronic polarization and polarizability at several temperatures.

In this work, density ρ , and speed of sound u , for citrate salts trisodium citrate (TSC) and tripotassium citrate (TPC) have been measured in (0.005, 0.01, 0.03 and 0.05) mol·kg −1 aqueous solution of ionic liquid 1-butyl-3-methylimidazolium tetrafluoro borate ([C 4 mim][BF 4 ]) at different temperatures T = (288.15, 293.15, 298.15, 303.15, 308.15) K at experimental pressure p = 0.1 MPa. Different parameters such as apparent molar volume (V ϕ ) , partial molar volume ( V ϕ 0 ), and standard partial molar volumes of transfer ( ΔV ϕ 0 ) have been calculated by using the experimental density data. From experimental speed of sound data apparent molar isentropic compression ( K ϕ , s ), partial molar isentropic compression ( K ϕ , s o ), and partial molar isentropic compression of transfer ( Δ K ϕ , s o ) have been calculated. The pair and triplet interaction coefficients have been calculated from transfer parameters. Infrared spectral studies have also been carried out for the present mixtures. Work is mainly concerned with the study of the interactions present in the mixtures of trisodium citrate and tripotassium citrate in aqueous solutions of ionic liquid 1-butyl-3-methylimidazolium tetrafluoro borate [C 4 mim][BF 4 ].

Herein, with the aim of shedding light on the effect of non-ionic co-solute (carbohydrate) stereochemistry on the aggregation and surface behaviour of ionic liquid-based surfactant 1-decyl-3-methylimidazolium bromide ([C 10 mim][Br]) in aqueous solution, we studied the surface tension, electrical conductivity, volumetric and compressibility properties for the aqueous solutions of [C 10 mim][Br] in the presence of different sugars containing pentose monosaccharides (xylose, ribose and arabinose), hexose monosaccharides (glucose, and mannose), disaccharides (sucrose and lactose) and trisaccharide (raffinose) at different temperatures. From the electrical conductivity measurements, the values of the degree of ionization of the counter ion on the micelles (α) and thermodynamic properties of micellization (Δ G m ) for [C 10 mim][Br] in aqueous carbohydrate solutions were obtained. The various parameters such as apparent molar volume ( V ϕ ), isentropic compressibility (κ s ), apparent molar isentropic compressibility ( K ϕ ) and the change of apparent molar properties upon micellization (Δ V ϕ,m and Δ K ϕ,m ) were derived from the experimental density and speed of sound data. The surface tension measurements provided a series of parameters, including surface tension at the cmc ( γ cmc ), effectiveness of surface tension reduction ( Π cmc ), maximum surface excess concentration ( Γ max ) and minimum surface area per molecule ( A min ) at interface of air/solution for the investigated surfactant in the presence of different sugars at 298.15 K. All the investigated carbohydrates have soluting-out effect (favouring the micelle formation) and their abilities to reduce the cmc of [C 10 mim][Br] in aqueous solutions increase with an increase in the hydrophilicity of the carbohydrate.

Inconsistencies in the apparent molar volume values for aqueous lithium tetraborate solutions reported by Guo and co-workers are exacerbated in the Corrigendum by Cao and co-workers. At 363 K the discrepancies relative to the corrected values in this work exceed 20 cm3 mol−1 and 100 cm3 mol−1 near 0.01 mol kg−1 for Guo et al. and Cao et al., respectively.

Acoustic and volumetric parameters for the liquid mixture (water + Biotin + ethylene glycol/diethylene glycol/triethylene glycol) are evaluated at different temperatures (288.15 K, 298.15 K, 308.15 K, and 318.15 K) and constant pressure of 0.1 MPa over the range of biotin concentrations (0.0000, 0.0015, 0.0025, and 0.0035) mol· K g - 1 . The experimental work was carried out by Anton Paar DSA 5000 M, where the density (ρ) and the speed of sound (c) are measured, which are later used to determine the various derived thermodynamic properties, such as, apparent molar properties (apparent molar volume, V ϕ ; apparent molar isentropic compression, K ϕ , S ), the partial molar properties (partial molar volume, V ϕ 0 ; partial molar isentropic compression, K ϕ , S 0 ), the partial molar transfer properties (partial molar volume of transfer, Δ V ϕ 0 ; partial molar isentropic compression of transfer, Δ K ϕ , S 0 ) and the partial molar expansibility ( E ϕ 0 ) along with its first derivative ∂ E ϕ 0 / ∂ T P . The obtained results are explained in terms of the kind of intermolecular interactions developed in the mixture using the co-sphere overlap model. Further, with the partial molar properties, the pair and triplet interaction coefficients (VAB, K A B ; VABB, K A B B ) are calculated.

The assessment of stability and behavior of ionic liquid is possible through the study of molecular interactions of the ionic liquid in water and mixed aqueous l -alanine solutions. We have studied density ( ρ ) and speed of sound ( u ) parameters at various temperatures. Derived parameters like apparent molar volume ( V ϕ ) and apparent molar isentropic compressibility ( K S , ϕ ) of solutes are calculated in the temperature range of 293.15 K–313.15 K. For aqueous binary and ternary solutions having ionic liquid [EMIm][MeSO4] and l -alanine as solute components. For ternary aqueous solutions concentration of l -alanine was kept constant (0.05 mol.kg−1). The limiting apparent molar volume ( V ϕ 0 ) and compressibility ( K S , ϕ 0 ) values for IL are estimated by using smooth extrapolation of V ϕ and K S , ϕ data. In both binary and ternary systems, the limiting apparent molar expansivity ( E ϕ 0 ) of solute and coefficient of thermal expansion ( α * ) and hydration number (nh) parameters have been calculated. The estimation of transfer parameters i.e., transfer volume and transfer compressibility results for transfer of IL from aqueous to aqueous l -alanine solutions are explained in terms of ion–solvent and hydrophobic interaction effects.

In this work, the densities of six binary mixtures containing N, N-dimethylcyclohexylamine (DMCHA) and n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol or n-decanol were measured at temperatures from (288.15 to 323.15) K and 0.1 MPa, over the full range of composition. Molar volume ( V m ), thermal expansion coefficient ( α p ), excess molar volume ( V m E ), apparent molar volume ( V φ ), apparent molar volume at infinite dilution ( V φ ∞ ), partial molar volume ( V ¯ )and excess partial molar volumes ( V ¯ E ) were calculated according to experimental density values. The results show that V m E values are negative ranging from (-1.0896 to 0) cm3·mol−1 and the minimum is observed around DMCHA mole fraction of 0.4 for all studied systems and temperatures. The variation of V m E value with composition and temperature were discussed and explained from molecular size and intermolecular interactions, namely dispersion forces and hydrogen bonds between DMCHA and alcohol. Furthermore, V m E values were also correlated using Redlich-Kister polynomial equation with the largest deviation of 0.019.

The salt-water interactions on single salt aqueous solutions of cesium sulfate and cesium chloride, as well as their mixing solutions, have been investigated by a combination of density measurements by an Anton Paar Digital vibrating-tube densimeter and the correction of the Pitzer model of electrolyte. The volumetric properties including apparent molar volume (Vϕ) and the coefficient of thermal expansion of the solution (α) of the binary systems (CsCl + H2O), (Cs2SO4 + H2O) and the ternary system (CsCl + Cs2SO4 + H2O) from 283.15 to 363.15 K at 5 K intervals and atmospheric pressure were derived. Variation trends of these volumetric properties against temperature and molality were revealed minutely. The Pitzer single salt parameters ( β MX 0 v , β MX 1 v and C MX v , MX = CsCl and Cs2SO4), mixing ion-interaction parameters ( θ Cl , S O 4 v and ψ Cs , Cl , S O 4 v ) as well as the correlation coefficient ai in the temperature-dependence equation (F(i, p, j) = a1 + a2ln(T/298.15) + a3(T-298.15) + a4/(620-T) + a5/(T-227)) have been obtained according to Pitzer ion-interaction model of electrolytes. These results are helpful to understanding the ion-interaction of aqueous solutions.