Search

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. [ABSTRACT FROM AUTHOR]

The density ( ρ ) and speed of sound ( u ) measurements at T  = (288.15–318.15) K and experimental pressure p  = 0.1 MPa is used for determining the interactions of citrate salts i.e. trilithium citrate (TLC) and triammonium citrate (TAC) with sucrose at different concentrations and different temperatures. The experimental values of density and speed of sound has been used for calculating the apparent molar volumes ( V ϕ ), partial molar volumes ( V ϕ o ) and partial molar volumes of transfer ( Δ V ϕ o ), partial molar expansion coefficients ( ∂ E ϕ o / ∂ T ) p , apparent molar isentropic compression ( K ϕ , s ), partial molar isentropic compression( K ϕ , s o ), partial molar isentropic compression of transfer ( Δ K ϕ , s o ) for sucrose in (0.0, 0.2, 0.4, 0.6) mol·kg −1 aqueous TAC and TLC solutions at temperatures in the range (288.15–318.15) K at experimental pressure p  = 0.1 MPa. The pair and triplet interaction coefficients have been calculated from partial molar volumes of transfer and partial molar isentropic compression of transfer. [ABSTRACT FROM AUTHOR]

To understand the solute-solute and solute-solvent interactions between the ionic liquids (ILs) and molecular solvent, in this work, we have measured thermophysical properties of pyrrolidinium based ILs in acetonitrile solutions. Also, the influence of IL cation chain length and temperature were quantified through derived volumetric and acoustic parameters. These derived properties were obtained from the measurement of the density ( ρ ), and speed of sound ( u ) for binary solutions of two ILs, i.e. 1-ethyl-1-methyl pyrrolidinium iodide and 1-methyl-1-propyl pyrrolidinium iodide with acetonitrile in the concentration range from 0.05 to 0.4 mol·kg −1 and the temperature range from 293.15 to 328.15 K at atmospheric pressure. Further, the Redlich-Mayer type of equation was fitted to these derived properties, apparent molar volume ( V ϕ ) and apparent molar isentropic compression ( K s , ϕ ), in order to evaluate the type and extent of interactions occurring between the studied ILs and acetonitrile. [ABSTRACT FROM AUTHOR]

The interactions of polyhydroxy solutes d (+)-glucose and d (−)-fructose with aqueous solutions of triammonium citrate (TAC) as a function of temperature have been enquired upon by combination of volumetric and ultrasonic studies. Densities and speed of sound of d (+)-glucose and d (−)-fructose in (0.2, 0.4 and 0.6) mol·kg −1 aqueous solutions of triammonium citrate (TAC) are measured at T  = (288.15, 298.15, 308.15 and 318.15) K and experimental pressure p  = 0.1 MPa. The apparent molar volume, V ϕ , the partial molar volume V ϕ o , and standard partial molar volumes of transfer, Δ V ϕ o for d (+)-glucose and d (−)-fructose from water to aqueous solutions of triammonium citrate (TAC) have been calculated from density 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 from ultrasonic speed data. The expansibility parameter ( ∂Vϕ 0 / ∂T ) p and its derivative ( ∂ 2 Vϕ 0 / ∂ 2 T ) p along with pair ( V AB , K AB ) and triplet ( V ABB , K ABB ) interaction coefficients have also been calculated. The results have been interpreted in terms of solute–solute and solute–solvent interactions in these systems. [ABSTRACT FROM AUTHOR]

Accurate measurements of volumetric and acoustic properties of aqueous ionic liquid solutions govern a key factor in process design and potential engineering applications. Also, such studies can give an appropriate idea about the nature and extent of intermolecular interactions involved between the solute and solvent in solutions. In this perceptive, the density and speed of sound for aqueous solutions of synthesized 1-alkyl-4-(4-sulfobutyl)-1H-1,2,4-triazol-4-ium trifluoromethanesulfonate based ionic liquids were measured as a function of temperature in the range of 293.15 to 328.15 K at atmospheric pressure. Additionally, effects of N-1 linear or branched alkyl substituent of studied ionic liquids in aqueous solutions on such properties were analyzed. Further, from the experimental data, derived parameters such as apparent molar volume ( V ϕ ), apparent molar isentropic compression ( K s,ϕ ) and limiting apparent molar expansion ( E φ ∞ ) have been evaluated. Moreover, for evaluating the extent of interactions stirring in the solutions, the apparent molar properties at infinite dilution were analyzed through Redlich-Mayer type equations. [ABSTRACT FROM AUTHOR]

In order to analyze the extent of solvation behaviour and stability of ascorbic acid (AA) in water or aqueous ionic liquid (IL) solutions, the knowledge of their thermodynamic properties is prerequisite which gives an appropriate idea about interactions involved in solutions. In addition, experimental and derived thermodynamic data is essential in effective process and product design involving these systems. In this report, we studied the volumetric and acoustic properties of AA in aqueous solution of synthesized IL, [HxTzm][CF 3 SO 3 ] i.e. (1-Hexyl-4-(4-sulfobutyl)-1H-1,2,4-triazol-4-ium trifluoromethanesulfonate) in temperature range of (293.15–328.15) K and at atmospheric pressure. Further, the experimentally measured thermodynamic properties were used to calculate apparent molar and partial molar properties, which elucidate the solvation behaviour of AA in presence of studied IL. Further, on the basis of the structural interaction model, various type of interactions which is stirring between AA and IL have been discussed in terms of partial molar properties at infinite dilution, transfer parameters and pair and triplet interaction coefficients. [ABSTRACT FROM AUTHOR]

The solvation behavior of ionic liquids containing a common, 1,1,3,3-tetramethylguanidinium cation and different anions, phenylacetate and cinnamate, in water is examined through apparent molar properties. These ionic liquids were chosen because of their versatile applications as environment-friendly solvent, catalyst, and for dissolution and stability of biomolecules. In order to understand the ion-ion and ion-solvent interactions and effect of anion in dilute aqueous solutions of studied ionic liquids, the experimental measurements of density and speed of sound have been carried out as a function of molality (0.01 to 0.2 mol·kg − 1 ) and temperature from 293.15 to 318.15 K. Experimental data have been used to calculate the apparent molar and other derived thermodynamic properties. Further, Redlich-Meyer equation has been employed to obtain the apparent molar volume and isentropic compressibility at infinite dilution and the empirical parameters which are crucial in understating the hydrophilic and hydrophobic nature of studied ionic liquids. [ABSTRACT FROM AUTHOR]

The density and speed of sound measurements have been carried out for some α-amino acids i.e. glycine, l -alanine and l -valine in aqueous diammonium hydrogen phosphate (DAP) at 10 K intervals, from 288.15 K to 318.15 K and experimental pressure p = 0.1 MPa. We have utilized the density and speed of sound data for determining the apparent molar and partial molar parameters concerning volumetric and compressibility properties. The group contribution of amino acids to partial molar volumes has also been perceived. The pair and triplet interaction coefficients obtained from partial molar volumes of transfer and partial molar isentropic compression of transfer illustrate the dominance of pairwise interactions. The possible molecular associations such as solute-solvent and solute-solute etc. are revealed by the present work and in due course, it has also been observed that all the amino acids in our present study, act as structure makers in aqueous solution of diammonium hydrogen phosphate (DAP). Apparent molar properties and partial molar properties anticipate the dominance of strong solute–solvent interactions over weak solute-solute in the studied ternary system. [ABSTRACT FROM AUTHOR]

The interactions of salt trilithium citrate (TLC) with saccharides d (+)-glucose and d (−)-fructose, have been investigated in aqueous medium from density ( ρ ) and speed of sound ( c ) measurements at T = (288.15–318.15) K and experimental pressure p = 0.1 MPa. The apparent molar volume ( V ϕ ), the partial molar volume ( V ϕ o ) and standard partial molar volumes of transfer ( Δ V ϕ o ) for both saccharides, from water to aqueous trilithium citrate (TLC) have been calculated from density data. The limiting apparent molar expansibilities have also been calculated. The 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 from speed of sound results. The pair and triplet interaction coefficients have been calculated from partial molar volumes of transfer and partial molar isentropic compression of transfer. A detailed insight into the physicochemical interactions e.g. ion–hydrophilic, hydrophilic–hydrophilic and hydrophilic–hydrophobic interactions in the saccharide-salt system along with the structure-making/structure-breaking tendency of the saccharides, have been retrieved through the perusal of these calculated parameters. [ABSTRACT FROM AUTHOR]

Apparent molar volumes ( V ϕ ) and apparent molar isentropic compression ( K ϕ , s ) of glycine, l -alanine, l -valine and l -leucine in (0.05, 0.10, 0.15, 0.20) mol·kg −1 aqueous solution of thiamine hydrochloride (thiamine-HCl) have been determined at T = (305.15, 310.15 and 315.15) K and experimental pressure p = 0.1 MPa, from the density and speed of sound measurements. The partial molar volume V ϕ o , standard partial molar volumes of transfer Δ V ϕ o for amino acids from water to aqueous thiamine-HCl, partial molar isentropic compression K ϕ , s and partial molar isentropic compression of transfer Δ K ϕ , s o have been calculated from the corresponding data. Group contributions of amino acids to partial molar volume are also determined. The pair and triplet interaction coefficients are obtained from partial molar volumes of transfer and partial molar isentropic compression of transfer. The partial molar expansibility ( ∂ V ϕ o / ∂ T ) p , second order derivative ( ∂ 2 V ϕ o / ∂ T 2 ) p have also been calculated. The parameters obtained have been used to explain the results in terms of (solute-solute)/(ion-ion), (solute-solvent) interactions, structure making and structure breaking behaviour of amino acids in aqueous thiamine-HCl solutions. [ABSTRACT FROM AUTHOR]

Apparent molar volumes and apparent molar isentropic compression have been determined for glycine, l -alanine, glycylglycine and phenylalanine in (0.01 and 0.03) mol kg − 1 in aqueous solutions of 1-hexyl-3-methylimidazolium chloride ([C 6 mim][Cl]) solutions by measurements of densities and speeds of sound at different temperatures. Apparent molar volumes V ϕ , partial molar volumes V ϕ 0 , transfer volumes Δ V ϕ 0 and hydration number, n H are evaluated using density data. Apparent molar isentropic compression K ϕ , s , partial molar isentropic compression K ϕ , S 0 , transfer isentropic compression Δ K ϕ , S 0 , and hydration number, n H have been calculated using speeds of sound data. The viscosity data have been analyzed by means of the Jones–Dole equation to obtain A and B -coefficients, free energy of activation of viscous flow per mole of solvent, Δ μ 1 0 ∗ , and solute, Δ μ 2 0 ∗ , enthalpy, Δ H 0 ∗ , and entropy of activation, Δ S 0 ∗ of viscous flow were evaluated. The behavior of these parameters has been interpreted in terms of solute–solute and solute–solvent interactions. [ABSTRACT FROM AUTHOR]

Densities, speeds of sound and viscosities of dipotassium hydrogen phosphate (DPHP) and disodium hydrogen phosphate (DSHP) in aqueous solutions of N-acetyl glycine (AcGly) are reported at different temperatures. Densities and speeds of sound have been used to calculate apparent molar volume, apparent molar isentropic compression, partial molar volume, partial molar isentropic compression, partial molar volume of transfer, partial molar isentropic compression of transfer and partial molar expansivity. Pair and triplet interaction coefficients have also been calculated. Experimental viscosities have been used to determine B -coefficients. Further pair and triplet interaction coefficients have also been calculated. The results are discussed in terms of solute–solvent interactions. [ABSTRACT FROM AUTHOR]

The precise determination of thermodynamic properties may provide an efficient way to investigate the structure change in aqueous hydrotrope solution. [Display omitted] • Liquid-liquid phase equilibrium for {water + tert -butanol + benzyl alcohol} ternary solution was determined at 298.15 K. • Density and conductivity of {water + tert -butanol + benzyl alcohol} ternary solution at different compositions were measured. • Structure changes in {water + tert -butanol + benzyl alcohol} ternary solution were discussed. In this work, the densities of {water + tert -butanol (TBA) + benzyl alcohol (BA)} ternary solutions were measured, from which the formation and structure transition in {water + TBA + BA} ternary solutions were investigated and discussed. In {water + TBA + BA} ternary solution, at fixed mole number of BA molecules, the BA molecules in the system first present as free BA molecules and BA/TBA dimers, while further increase of TBA concentration would result in the interactions of BA molecules with different types of TBA/water aggregates that was directly reflected by the change of the volumetric properties. Moreover, the change of molar conductivity Λ m (NaBr) of NaBr and the maximum absorbance length of methyl orange λ max in ternary system have been determined at different fixed values of TBA concentrations, where various changes of Λ m (NaBr) and λ max with BA mass fraction were displayed due to the formation and transition of different microstructures. The results reported herein suggested that the fine structure transitions in hydrotrope solutions can be well reflected by the variance of thermodynamic properties, which may provide an efficient way to investigate the structure change in aqueous hydrotrope solution. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1-alkyl-1-methyl pyrrolidinium iodide ionic liquids (ILs) have been synthesized. • Thermal decomposition temperature decreased with increasing chain length of ILs. • Apparent molar properties are escalated with cationic chain length of ILs. • Solute-solvent interactions of ILs in acetonitrile are predominant at low temperature. Detailed analysis of volumetric and acoustic properties of the dilute solution of ionic liquids (ILs) and acetonitrile play a significant role in the potential engineering field and process design. Moreover, these studies can provide relevant knowledge about the types and scope of the intermolecular interactions governed between the solute and solvent. In this work, three iodide based pyrolidium ILs, i.e. 1-butyl-1-methyl pyrrolidinium iodide, [BMPY]I and 1-methyl-1-pentyl pyrrolidinium iodide, [PeMPY]I and 1-hexyl-1-methyl pyrrolidinium iodide, [HMPY]I were synthesized and studied their density and sound velocity in acetonitrile as a function of molality in the range of 0.05–0.4 mol·kg−1 and temperature in the range from 293.15 to 328.15 K at atmospheric pressure. The impact of chain length of cation and temperature were premeditated by using well-known volumetric and acoustic factors. In addition, by employing the experimental data, the apparent molar volume (V ϕ), apparent molar isentropic compression (K s,ϕ), and limiting apparent molar expansion (E φ ∞) were calculated. Further, the apparent molar properties at infinite dilution were examined by using Redlich-Mayer type equations. Furthermore, measured and calculated properties have been analysed to understand the solute-solvent interaction in studied systems. For the studied systems, infinite dilution apparent molar properties were increased with cationic chain length on the ILs, however, decreased with temperature. [ABSTRACT FROM AUTHOR]