Isentropic Compressibility Δκs Research Articles

PC-SAFT model and experimental explicating interaction of binary and ternary systems of 2-ethoxyethanol, methylcyclohexane and N-methylcyclohexylamine

In this project upon measurements of density ρ, speed of sound u, and refractive index nD, the excess molar volumes VmE, deviations in isentropic compressibility ΔKs, and in refractive index ΔnD, were calculated for the whole range of composition and temperatures of T = (298.15–308.15–318.15)K for binary and ternary systems of 2-ethoxyethanol, methylcyclohexane, and N-methylcyclohexylamine. Results correlated with the Redlich-Kister and Cibulka equations. The Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state was used to predict density and there was a good agreement between calculated and experimental density. Intermolecular interactions between like and unlike molecules were discussed for the systems. It seems that study provides useful insights into the properties and behavior of these mixtures, which could have potential applications in various fields such as chemistry and materials science.

Spectroscopic and thermodynamic studies on binding behaviour of an ionic liquid, 2′,3′-Epoxypropyl-N-methyl-2-oxopyrrolidinium acetate, with bovine serum albumin (BSA)

Spectroscopic and thermodynamic investigation of molecular interactions in a binary mixture of 2′,3′-epoxypropyl-N-methyl-2-oxopyrrolidinium acetate ([EPMpyr][OAC]) ionic liquid (IL) with a bovine serum albumin (BSA) aqueous solution was carried out. The thermophysical properties of density (ρ) and speed of sound (u) were first measured for the binary mixture at different mole concentrations in the temperature range from 293.15–323.15 K at a 5 K interval at atmospheric pressure. Using the above data, the thermodynamic properties of excess molar volume (VmE), isentropic compressibility (ks), deviation in isentropic compressibility Δks and intermolecular free length Lf were derived. These thermodynamic parameters have been used to get more information about the interaction of IL with BSA. In addition, absorption, steady state emission, synchronous emission, three-dimensional (3D) emission and circular dichroism (CD) have been exploited to acquire an understanding of the binding mechanisms and binding strengths of the interactions between the IL and BSA. Emission quenching results clearly indicate that the effect of IL on trypthophan of BSA. This work was undertaken with the expectation of getting results which would cast light on the types of interactions occurring between [EPMpyr][OAC] and BSA molecule. Furthermore, the data emanating from this work may help researchers in the bio-pharmaceutical sector developing more active IL based drugs. Moreover, this work can provide valuable information of potential interest to researchers in biotechnology including drug bioengineering.

Thermo physical and FT-IR study on binary mixtures of 2-isopropoxy ethanol and alcohols at different temperatures

As a continuation to our investigations on thermodynamic properties of binary mixtures of alkoxy alkanols with alcohols, the present paper reports the experimental data for the densities, speeds of sound and viscosities for the binary mixtures of 2-isopropoxy ethanol with alcohols. Densities and speeds of sound of 2-isopropoxy ethanol (CH3)2CH2OC2H4OH and alcohols namely1-hexanol C6H14O, 1-octanol C8H18O and 1-decanol C10H22O and their binary mixtures with 2-isopropoxy ethanol as a common component have been measured over the full range of composition at atmospheric pressure and at different temperatures 293.15, 298.15, 303.15, 308.15 and 313.15K and viscosities have also been measured at 298.15, 303.15 and 308.15K over the full range composition. The experimental data were used to calculate the values of excess molar volumes VmE, deviations in isentropic compressibility Δκs, deviations in speed of sound Δu, deviations in viscosity Δη and excess Gibbs free energies ΔG∗E at all mole fractions of (CH3)2CH2OC2H4OH. The observed variations of these parameters with composition and temperature are discussed in terms of the molecular interactions due to physical and chemical effects between the unlike molecules of the binary mixtures. Further, experimental densities were used to estimate partial molar volumes V¯m,1, excess partial molar volumes V¯m,1E and their limiting values at infinite dilution V¯m,i∞ and V¯m,iE,∞, respectively. These parameters, especially excess functions are found to be quite sensitive towards the intermolecular interactions in liquid mixtures. The excess functions and deviations have also been correlated using Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors. A study of above discussed parameters is used to throw light on the interactions existing between the constituents of the binary mixtures. FT-IR technique has been used to scrutinize the –OH interactions between the binary mixtures and is very valuable to spot the influence on the structural variation in the alcohols.

Thermophysical and thermoacoustical properties of acetophenone with ethyl butyrate at temperatures of 303.15, 313.15, and 323.15 K

Densities, viscosities, and ultrasonic velocities of the binary mixtures of acetophenone with ethyl butyrate were measured over the entire mole fractions at 303.15, 313.15, and 323.15 K. From these experimental results, excess molar volume VE, viscosity deviation Δη, deviations in isentropic compressibility Δκs, excess intermolecular free length ΔLf, and excess Gibbs free energy ΔG*E were calculated. The viscosity values were fit to the models of Krishnan–Laddha and McAllister. The thermophysical properties under study were fit to the Jouyban–Acree model. The excess values were correlated using Redlich–Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

Molecular interactions in binary mixtures of 1-butoxy-2-propanol with alcohols at different temperatures: A thermophysical and spectroscopic approach

This paper reports densities (ρ) and speeds of sound (u) of 1-butoxy-2-propanol CH3(CH2)3OC3H6OH, 1-propanol CH3(CH2)2OH, 2-propanol (CH3)2CHOH, 1-butanol CH3(CH2)3OH and 2-butanol CH3CH2CH(OH)CH3 and their binary mixtures with 1-butoxy-2-propanol as a common component, measured at T=(293.15, 298.15, 303.15, 308.15 and 313.15)K over the entire composition range. These experimental values of density and speed of sound were used to calculate the values of excess molar volumes, VmE, deviations in molar isentropic compressibility Δκs and deviations in speed of sound uD. Further, experimental densities were used to estimate apparent molar volumes Vϕ,i, partial molar volumes V‾m,1, excess partial molar volumes V‾m,1E and their limiting values at infinite dilution Vϕ,i∞, V‾m,i∞ and V‾m,iE,∞ respectively. The variations observed in these properties, with composition and temperature, are discussed in terms of molecular interactions due to physical and chemical effects between the unlike molecules of the binary mixtures. These properties, especially excess functions, are found to be quite sensitive towards the intermolecular interactions in liquid mixtures. These excess functions and deviations have also been correlated using Redlich–Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors. FT-IR studies of these mixtures are also reported.

Densities, viscosities, sound speed, and IR studies of N-methyl-2-pyrrolidone with cyclohexylamine, cyclohexanol, and cyclohexene at different temperatures

Abstact Densities, viscosities, and speeds of sound of the binary liquid mixtures of N-methyl-2-pyrrolidone (NMP) with cyclohexylamine (CHA), cyclohexanol (CHOL) and cyclohexene (CHE) at temperatures of 303.15–318.15 K are measured over the entire composition range. From the experimental values excess molar volume V m E , deviation in isentropic compressibility Δks, excess free length L f E , deviation in viscosity Δη are computed. The variation with the temperature and concentration is discussed in terms of molecular interactions. All the excess parameters and deviations are fitted to Redlich–Kister polynomial equation to estimate the binary interaction parameters and mean deviation from the regression lines. The sign and magnitude of the computed parameters are discussed to reveal the nature and type of interactions existing between the component molecules in the binary mixtures. Thermodynamic investigations under the present study reveal the strong inter molecular interactions between the unlike molecules in the binary systems of NMP + CHA, NMP + CHOL, whereas in the other binary system NMP + CHE the reverse trend is observed due to dispersion forces. The strength of interaction of CHA, CHOL, and CHE with NMP found to follow the order: CHA > CHOL > CHE. FT-IR studies of these mixtures have been estimated and analyzed to study the interactions between unlike molecules. A good agreement is observed between the excess parameters and FT-IR studies.

Densities, Viscosities, and Sound Speed of Binary Mixtures of Hexyl Acetate with Tetrahydrofuran, 1,4-Dioxane, Anisole, and Butyl Vinyl Ether

Densities, viscosities, and speeds of sound for the binary mixtures of hexyl acetate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether were measured at (298.15, 303.15, 308.15, and 313.15) K. From the experimental data, values of excess volume, VE, deviation in viscosity Δη, and deviation in isentropic compressibility ΔKS, have been calculated. These results were fitted to Redlich–Kister polynomial equation. The excess volumes VE and deviations in isentropic compressibility ΔKs were found to be completely negative, while the deviations in viscosity Δη were found to be either negative or positive depending on the nature of liquid mixtures.

Effect of structural alteration of ionic liquid on their bulk and molecular level interactions with ethylene glycol

Mixing behavior of ionic liquids (ILs), 1-pentyl-3-methylimidazolium bromide [C5mim][Br], 1-pentyl-3-methylimidazolium tetrafluoroborate [C5mim][BF4] and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [C4mmim][BF4] with ethylene glycol has been investigated using density, ρ, speed of sound, u, and Fourier transform infrared spectroscopy (FTIR) measurements over the whole composition range at T=(288.15–318.15)K. The density values were used to calculate excess molar volumes, VmE, whereas speed of sound results have been used to calculate deviation in isentropic compressibility ΔκS. Excess properties have fitted to the Redlich–Kister polynomial equation to obtain the binary coefficients and the standard deviations. The excess properties and spectroscopic data have been analyzed in terms of effect of temperature, anion and cation of IL. The results indicates about the significance of C(2) position of the imidazolium ring in combination with the nature of anion in deciding the bulk and molecular level interactions.

Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15) K

Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15) K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been fitted to Redlich-Kister equation to determine the appropriate coefficients. The values of excess volume VE and deviation in viscosities Δη are negative over the entire range of composition for all the binary systems at the studied temperatures. The behavior of these parameters with composition of the mixture has been discussed in terms of molecular interactions between the components of liquids.

Density, speed of sound, refractive index and derivatives properties of the binary mixture n-hexane + n-heptane (or n-octane or n-nonane), T = 288.15 – 313.15 K

This article reports experimental values of refractive index nD , density ρ, speed of sound u, isentropic compressibility κs, excess molar volume of mixing V E, deviations of refractive index δnD and isentropic compressibility δκs of the binary mixture n-hexane + n-alkane from T = (288.15 to 323.15) K and atmospheric condition. The corresponding excess derived property was computed from the experimental data. Parameters of analytical expressions which represent the composition dependences of the derived property are reported. Values of physical properties were compared with the results obtained by different prediction methods.

The variation of viscosity, refractive indices, compressibility, intermolecular free length, and excess molar volume of the acetophenone—ethyl acetate solutions at 303.15–323.15 K

Densities, viscosities, refractive indices and ultrasonic velocities of the binary mixtures of acetophenone with ethyl acetate were measured over the entire mole fractions at 303.15, 313.15, and 323.15 K. From the experimental results, excess molar volumes VE, viscosity deviation Δη, refractive index deviation ΔnD, deviations in isentropic compressibility Δκs and excess intermolecular free length ΔLf are calculated. The viscosity values were fitted to the models of Krishnan-Laddha and McAllister. The thermophysical properties under study were fit to the Jouyban-Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

Effect of β-cyclodextrin on the behaviour of thermophysical and spectroscopic properties of binary mixtures of (isomeric butanediol + pyrrolidin-2-one)

Thermophysical parameters viz. excess molar volume VE, speed of sound u, viscosity η and spectroscopic parameters viz. FT-IR, 1H and 13C NMR have been measured for the ternary liquid mixtures of {isomeric butanediol (butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, butane-2,3-diol)+pyrrolidin-2-one} in β-cyclodextrin over the whole composition range at T=308.15K. The deviation in the isentropic compressibility ΔκS, partial molar quantities QiE, deviation in viscosity Δη, deviation in Gibbs energy of activation for viscous flow g(x) and excess NMR chemical shift δE have been estimated and analysed. Results indicate that the position of hydroxyl groups of butanediol showed a noticeable effect on the thermophysical properties. Furthermore, the effect of addition of β-cyclodextrin caused significant changes, due to difference in the fitting of isomeric butanediol in the hydrophobic cavity of β-cyclodextrin. Particularly, visible changes in thermophysical properties of 1,4-BTD system have been observed in comparison to other isomers of BTD indicating that hydrogen bonding and affinity of fitting between (1,4-BTD and β-CD+PY) are greater than the other isomers. These results have been found to be in excellent concurrence with NMR and FT-IR studies. However, for 2,3-BTD and 1,3-BTD systems dispersion forces due to dissociation of self-associated PY and diols are predominant. The spectroscopic measurements (FT-IR, 1H and 13C NMR) confirm that the interaction between unlike molecules take place through hydroxyl groups of isomeric butanediol and carbonyl group of pyrrolidin-2-one.

Studies of thermophysical properties of binary liquid mixtures of amine and alcohols at various temperatures

The density ρ and speed of sound u of the binary mixtures of ethylenediamine (EDA) with alcohols (1-hexanol, 1-octanol, and 1-decanol) were measured at temperatures from (293.15 to 313.15)K and viscosity η at (298.15 to 308.15)K over the entire composition range and at atmospheric pressure. Using the experimental values of density, viscosity and speed of sound, the excess molar volume VmE, viscosity deviation Δη, deviation in speed of sound uD, deviation in isentropic compressibility Δκs were calculated. These results were fitted to the Redlich–Kister type polynomial equation. The variations of these excess parameters with composition were discussed from the viewpoint of intermolecular interactions in these mixtures. The excess properties are found to be either positive or negative depending on the molecular interactions and the nature of liquid mixtures. Further, the viscosity data have been used and analyzed in terms of Heric−Brewer and McAllister models.

Thermophysical and spectroscopic studies of room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate in Tritons

The thermophysical properties viz. density ρ, speed of sound u, and specific conductivity κ of pure room temperature ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) and its binary formulations with Triton X-45 and Triton X-100 have been studied over the entire composition range at different temperatures (293.15 to 323.15)K. Excess molar volume VE, deviation in isentropic compressibility ΔKS, partial molar excess volume ViE, deviation in partial molar isentropic compressibility ΔKS,i, deviation in specific conductivity Δκ have also been estimated and analysed. Spectroscopic properties (IR, 1H and 13C NMR) of these mixtures have been investigated in order to understand the structural and interactional behaviour of formulations studied. The magnitude of interactions between the two components increases with addition of number of oxyethylene groups in Tritons and with rise in temperature. Spectroscopic measurements indicate that interactions are mainly taking place through the five member ring of room temperature ionic liquid and six member ring of Tritons.

Volumetric and Transport Properties of Binary Liquid Mixtures of Phenylacetonitrile with Aliphatic Esters at Temperatures of (303.15 to 313.15) K

The present paper reports the experimental data for density, ρ, viscosity, η, and speed of sound, u, for the binary mixtures of phenylacetonitrile (PAN) with aliphatic esters [ethyl acetate (EA), ethyl chloroacetate (ECA), and ethyl cyanoacetate (ECNA)] over the miscibility region (0 < x1 < 1) at temperatures of (303.15, 308.15, and 313.15) K. The experimental data have been used to calculate various properties like the excess molar volume VE and deviation in isentropic compressibility Δκs. These properties are used to interpret the molecular interactions in the binary mixtures. The Redlich−Kister polynomial equation was fitted to the experimental data to derive binary coefficients and standard deviations.

Excess Molar Volumes and Sound Speed in (Phenylacetonitrile + 1,2-Dichloroethane), (Phenylacetonitrile + 1,1,2-Trichloroethane), (Phenylacetonitrile + 1,1,2,2-Tetrachloroethane), (Phenylacetonitrile + Trichloroethene), and (Phenylacetonitrile + Tetrachloroethene) at Temperatures of (303.15, 308.15, and 313.15) K

The present paper reports the experimental data for density ρ, viscosity η, and speed of sound u in (phenylacetonitrile + 1,2-dichloroethane), (phenylacetonitrile + 1,1,2-trichloroethane), (phenylacetonitrile + 1,1,2,2-tetrachloroethane), (phenylacetonitrile + trichloroethene), and (phenylacetonitrile + tetrachloroethene) over the entire range of composition at T = (303.15 to 313.15) K. These values have been used to calculate the excess molar volumes VE and deviation in isentropic compressibility Δκs. The excess molar volumes and deviation in isentropic compressibility are fitted to a Redlich−Kister-type equation to derive binary coefficients and standard deviation and to elicit the specific interactions like complex formation as well as the saturation of chlorine atoms with π electrons.

Densities, Sound Speed, and IR Studies of (Methanol + 1-Acetoxybutane) and (Methanol + 1,1-Dimethylethyl Ester) at (298.15, 303.15, 308.15, and 313.15) K

Densities and sound speeds for (methanol + 1-acetoxybutane) and (methanol + 1,1-dimethylethyl ester) have been measured over the entire range of compositions, at temperatures of (298.15, 303.15, 308.15, and 313.15) K and at atmospheric pressure of about 0.1 MPa. From the experimental values of density and ultrasonic velocity, the excess molar volumes VE and deviations in isentropic compressibility Δκs have been calculated. The VE and Δκs are negative for both the binaries studied over the whole composition. FT-IR studies of these mixtures are also carried out at T = 298.15 K.

Ultrasonic velocity, density, viscosity and their excess parameters of the binary mixtures of tetrahydrofuran with methanol and o-cresol at varying temperatures

Abstract The ultrasonic velocity, density and viscosity of binary mixtures of tetrahydrofuran (THF) with methanol and o-cresol were measured at 293, 303 and 313 K over the entire range of composition. Using these experimental data, various thermo-acoustic parameters such as deviation in isentropic compressibility Δκs, excess molar volume V m E , viscosity deviation Δη and excess Gibb’s free energy of activation for viscous flow ΔG∗E have been calculated and fitted to Redlich–Kister polynomial equation. The deviation/excess parameter were plotted against the mole fraction of THF over the whole composition range. The observed negative and positive values of deviation/excess thermo-acoustic parameters were explained on the basis of the intermolecular interactions present in these mixtures. Since methanol is less acidic than o-cresol, the removal of proton from methanol is less likely than the removal of proton from o-cresol which is more acidic than methanol. Hence the intermolecular interaction in the mixture of THF with o-cresol is found to be stronger than mixture of THF with methanol, which is reflected from the observed positive and negative values of excess thermo-acoustic parameters. Thus it may be concluded that THF + o-cresol mixture exhibits strong intermolecular interaction. However, dispersive forces are responsible for THF + methanol mixture due to weak interaction. Further, Nomoto, Junjie, CFT and Flory’s theory were applied for evaluating the ultrasonic velocity theoretically. The theoretical evaluation of ultrasonic velocity based on molecular models in liquid mixtures has been used to correlate with the experimental findings and to know the thermodynamics of the mixtures. The comparison of theoretical and experimental results provides better understanding about the validity of the various thermodynamic, empirical, semi empirical and statistical theories.

Density and Viscosity of Acrylonitrile + Cinnamaldehyde, + Anisaldehyde, and + Benzaldehyde at (298.15, 308.15, and 318.15) K

The excess molar volume VE and viscosity deviations Δη have been derived from density ρ and viscosity η measurements of the binary mixtures of acrylonitrile with cinnamaldehyde, anisaldehyde, and benzaldehyde measured at (298.15, 308.15, and 318.15) K. The data have been correlated with the Grunberg−Nissan equation. Moreover, deviations in isentropic compressibility ΔKS have been calculated from ultrasonic speed measurements of these binary mixtures at 298.15 K. These results were fitted to the Redlich−Kister polynomial equation.

Viscosity, Density, and Speed of Sound for the Binary Mixtures of Formamide with 2-Methoxyethanol, Acetophenone, Acetonitrile, 1,2-Dimethoxyethane, and Dimethylsulfoxide at Different Temperatures

Densities and viscosities of binary liquid mixtures of formamide with 2-methoxyethanol, acetophenone, acetonitrile, 1,2-dimethoxyethane, and dimethylsulfoxide have been measured at (298.15, 308.15, and 318.15) K and over the entire composition range at p = 0.1 MPa. Ultrasonic speeds of these binary liquid mixtures have also been measured at 298.15 K and the same pressure. From the experimental data, values of excess molar volume , viscosity deviation Δη, and deviation in isentropic compressibility ΔKS have been determined. These results were fitted to the Redlich−Kister-type polynomial equation. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models.