Excess Thermal Expansion Coefficients Research Articles

Volumetric properties for binary mixtures of ethyl acetate, vinyl acetate and tert-butyl acetate with 1-propanol and iso-butanol at T = (293.15–313.15) K and P = 0.087 MPa

Based on density measurement, we appraised and reported partial molar volumes and thermal expansion coefficients along with their excess values for six binary mixtures of 1-propanol or iso-butanol with vinyl, ethyl and tert-butyl acetate. Temperature range was (293.15–313.15) K and whole range of composition at ambient pressure (0.087MPa) is considered. Results showed that excess molar volumes for all mixtures are positive and increased with temperature. Also the excess thermal expansion coefficients were positive and demonstrate small positive sensitivity to temperature change. Results are explained based on intermolecular interactions and also Redlich–Kister equations were fitted to excess molar volume data.

Thermophysical and transport properties of binary mixtures containing triethylene glycol and alcohols at different temperatures

Densities and viscosities have been measured for the binary mixtures of triethylene glycol with + 2-propanol, 2-butanol and 2-pentanol over the entire range of mole fraction at T = 293.15–323.15 K. From experimental data, the excess molar volume, thermal expansion coefficient, excess thermal expansion coefficient and deviation in viscosity were calculated. The experimental results have been discussed in terms of molecular interactions and formation of molecular complexes between unlike molecules. Influence of temperature and carbon chain length of alcohols on mentioned properties was discussed. Moreover, the friction theory coupled with PC-SAFT equation of state was applied to produce the viscosities of pure data and binary mixtures.

Density, viscosity and excess properties in the trihexyltetradecylphosphonium chloride ionic liquid/methanol cosolvent system

The volumetric and viscosity behaviors of binary mixtures of (trihexyl(tetradecyl)phosphonium chloride ionic liquid+methanol) ([P14,6,6,6+][Cl−]+MeOH) have been described across the entire range of mol fraction [P14,6,6,6+][Cl−] (xIL=0 to 1) and over a temperature range of (290.15 to 313.15)K at p=0.1MPa. All binary mixtures were liquids completely miscible. The experimental data was used to calculate the excess molar properties of these solutions. The variation of density was used to compute excess molar volumes, VE, and partial molar volumes of each component and the excess thermal expansion coefficients, αPE. For each of these excess parameters, the deviations were observed to be negative over the entire range of mole fraction and temperature. Viscosity deviations, Δη, from the ideal mixtures were calculated from the measured viscosities. Additionally, temperature dependent viscosities were observed to follow an Arrhenius activation model and the activation energy, Ea, of viscous flow was computed. Combined viscosity and volumetric data were used to calculate the excess Gibbs free energy, ΔGmE∗, of activation of viscous flow. The results from the excess solution properties behaviors have been discussed in terms of molecular interactions and support the presence of strong interactions in solution. These interactions are typical of IL aggregation. In this IL/cosolvent system the most significant changes occur up to xIL∼0.4.

Measurement and Modeling of Volumetric Properties and Speeds of Sound of Several Mixtures of Alcohol Liquids Containing Butanediol

Densities and speeds of sound for the pure as well as binary mixtures of 1,2-butanediol and benzyl alcohol, 2-phenylethanol, 2-butanol, and 1,3-butanediol were measured over the 0 to 1 composition range and at six different temperatures between 298.150 K and 323.150 K with an interval of 5 K and at atmospheric pressure using a vibrating tube densimeter.The experimental values were used to calculate excess molar volume, VmE, excess isentropic compressibility, KSE, excess thermal expansion coefficient, αpE, infinite partial molar volumes, Vi∞ and excess partial molar volumes at infinite dilution, ViE,∞. The sign and magnitude of mixing quantities have been used to discuss the nature and strength of molecular interactions in binary mixtures. The calculated excess values and deviation quantities were fitted to the Redlich–Kister polynomials equation. Furthermore, it has been checked how the calculated values of densities and excess molar volumes using the Tao–Mason equation of state compare with the experim...

Volumetric properties for binary and ternary mixtures of allyl alcohol, 1,3-dichloro-2-propanol and 1-ethyl-3-methyl imidazolium ethyl sulfate [Emim][EtSO4] from T = 298.15 to 318.15 K at ambient pressure

Based on density measurements, volumetric properties including excess molar volumes, partial molar volumes, partial molar excess volumes and their infinite dilution values, for binary and ternary solutions of allyl alcohol, 1,3-dichloro-2-propanol and 1-ethyl -3-methyl imidazolium ethyl sulfate [Emim][EtSO4] have been determined. Entire range of composition and temperatures from T=(298.15–318.15)K at ambient pressure (0.087MPa) have been considered. The excess molar volumes were negative for two binary mixtures including allyl alcohol whereas were positive for solutions of ionic liquid+1,3-dichloro-2-propanol. These quantities, for all binary mixtures, showed decrease by increasing temperatures which are explained based on intermolecular interactions and steric effects. Thermal expansion coefficients and their excess values have also been appraised for binary mixtures. The excess thermal expansion coefficients were negative for all binary mixtures and increased by raising temperature. The excess molar volumes have been modeled by Redlich–Kister equation for binary solutions and by Singh, Nagata–Tamura and Cibulka equations for ternary mixture.

Liquid densities and excess molar volumes of ethanol + biodiesel binary system between the temperatures 273.15 K and 333.15 K

The densities of ten binary mixtures of biodiesel made from rapeseed oil and ethanol have been measured for eight temperatures within the range between 273.15K and 333.15K, using an Anton Paar DMA 4500 M densimeter. The excess molar volume has been calculated from experimental densities. Variation of mixtures volumes was low, but measurable. It was observed that the excess molar volume was positive for all studied mixtures, due to increased physical interactions between fatty acid methyl esters and ethanol. Density variation was modeled by polynomial regression and the thermal expansion coefficient, as well as its excess value, were estimated. The excess molar volume and excess thermal expansion coefficient results were fitted to the Redlich–Kister type polynomial equation to obtain the regression coefficients and estimate the standard deviations and correlation coefficients between experimental and calculated results.

Measurement and modeling of volumetric properties and sound speeds of several mixtures of alcohol liquids containing 1-propanol and 2-propanol at T = (298.15–323.15) K and ambient pressure

The sound speeds and densities for six binary mixtures containing 1-propanol and 2-propanol were measured over the whole composition range at temperatures between 298.15 and 323.15K at 5K interval and ambient pressure using a vibrating U-tube densimeter. By employing the experimental densities and sound speeds, the excess molar volumes, VmE, the excess isentropic compressibility, kSE, the excess thermal expansion coefficients, αPE and the excess partial molar volumes at infinite dilution, V¯iE,∞ were computed. Furthermore, the strength of intermolecular forces in these mixtures has been investigated. From the results obtained, the excess molar volumes are negative over the whole mole fraction range for all studied binary mixtures and become more negative with increasing the temperature. The above-mentioned properties were correlated with Redlich–Kister equation.

Densities, Excess Molar Volumes, and Thermal Expansion Coefficients of Aqueous Aminoethylethanolamine Solutions at Temperatures from 283.15 to 343.15K.

The densities of aqueous mixtures of aminoethylethanolamine (CAS #000111-41-1) were measured over the entire compositional range at temperatures of 283.15–343.15 K. The results of these measurements were used to calculate excess molar volumes and isobaric thermal expansion coefficients, and partial molar and apparent molar volumes and excess isobaric thermal expansion coefficients were subsequently derived. The excess molar volumes were correlated as a function of the mole fraction using the Redlich–Kister equation. Temperature dependences of the Redlich–Kister coefficients are also presented. The partial molar volumes at infinite dilution of AEEA in water were determined using two different methods. In addition, the solution density was correlated using a Joubian–Acree model. Aqueous solutions of AEEA exhibit similar properties to the aqueous solutions of other alkanolamines (like monoethanolamine) used in acid gas sweetening.

Physical properties of phosphonium ionic liquid and its mixtures with dodecane and water

Addition of molecular solvents, dodecane and water, to the hydrophobic phosphonium ionic liquid (IL) tetradecyltrihexylphosphonium bis-(2,4,4-trimethylpentyl)phosphinate decreases its density and viscosity significantly. These changes have been studied in the temperature interval between 15 and 60°C and explained in terms of structural changes. Dependences of density and viscosity on the composition of binary and ternary systems are strongly nonlinear. Excess molar volumes and thermal expansion coefficients have been estimated for dry and water saturated solvents with IL. Strong H-bonding in water saturated solvents has been concluded from large negative excess molar volumes and strong temperature dependence of the density in water saturated solvents. VFT, Litovitz and Arrhenius models were tested for the correlation of temperature dependence of pure IL viscosity, showing that IL is a typical strong liquid. Deviations of the viscosity of the solvents to the ideal mixture viscosity based on the Eyring’s theory of absolute rates were evaluated. In dynamic light scattering measurements, two different types of aggregates have been identified in the dry and water saturated solvents, with the mean size above 300 and 2nm, respectively. High content of water of up to 8 molecules per ion pair of IL points to the existence of reverse micelles in the water containing solvents with hydrophobic IL.

Volumetric and compressibility studies on extractant-diluent system: effect of chain length

The experimental densities ρ and sound velocities u for binary mixtures of TBP–dodecane have been measured at temperatures from 298.15 to 323.15 K and atmospheric pressure over the whole mole fraction range. From these data, the excess molar volume (VE) and deviation in isentropic compressibility (Δks) have been calculated and fitted to Redlich–Kister polynomial equation. VE and Δks values are positive for TBP–dodecane over the whole mole fraction range and at the above-mentioned temperatures. Excess thermal expansion coefficients (αE) of a mixture of equimolar composition and deviations in molar volume of the components at infinite dilution have been calculated at all temperatures. The variations of these properties with composition and temperature of the binary mixture are discussed in terms of molecular interactions.

Measurements of some physical properties of binary liquid mixtures (N-methyl-2-pyrrolidone + an aliphatic ester) at several temperatures and data processing of viscosity and ultrasonic speed

The ultrasonic speed (U) studies are carried out using single crystal variable path fixed frequency (2MHz) ultrasonic interferometer on some aliphatic esters in N-methyl-2-pyrrolidone (NMP) at temperatures of 303.15, 308.15, 313.15 and 318.15K. Excess molar volume, excess isobaric thermal expansion coefficient, excess isentropic compressibility and excess ultrasonic speed are computed from the experimentally measured ultrasonic speeds and densities of pure liquids NMP, methyl acetate (MA), ethyl acetate (EA), butyl acetate (BA) and their binary mixtures over the entire range of composition of NMP. The variation of these properties with composition and temperature of the binary mixtures is discussed in terms of molecular interactions of component molecules. The excess parameters are fitted to a Redlich–Kister type polynomial and the corresponding standard deviations are calculated. Thermodynamic parameters under study suggest the existence of strong interactions between NMP and aliphatic esters. The experimental data of viscosity is used to test the applicability of empirical relations of Grunberg–Nissan, Katti–Chaudhri, Heric–Brewer and McAllister for the systems studied. Also, ultrasonic speeds are theoretically evaluated based on scaled particle theory and compared with the experimentally measured values. The study reveals a close agreement between experimental and theoretical values of ultrasonic speed of these mixtures at all the temperatures under study. An attempt is made to study the temperature effect on the shapes of the interacting molecules in the binary liquid mixture using scaled particle theory in the temperature range 303.15–318.15K.

Excess molar volumes, viscosity deviations and excess thermal expansion coefficients for binary and ternary mixtures consist of diethylketone + 2-butanol + ethylchloroacetate at (298.15, 308.15 and 318.15) K

Densities and viscosities for ternary mixtures of diethylketone+2-butanol+ethylchloroacetate, and related binary mixtures have been reported as a function of mole fraction at temperatures (298.15K, 308.15K and 318.15K) for binary and 298.15K for ternary mixtures. Excess molar volumes VmE, viscosity deviations Δη, and excess thermal expansion coefficients αE, were calculated from the experimental data. Redlich–Kister and Cibulka equations were used to correlation of calculated data for binary and ternary mixtures, respectively. The experimental results of VmE are positive for the mixtures of (diethylketone+2-butanol) and (2-butanol+ethylchloroacetate) and negative for (diethylketone+ethylchloroacetate) over the whole composition range. The values of Δη are negative for three binary mixtures. The results were analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

Densities and Excess Properties of Primary Amines in Alcoholic Solutions

In the present work, experimental values for the densities of primary amines (monoethanolamine and diglycolamine) in alcoholic solutions were studied at atmospheric pressure (97.57 kPa) using an Anton Paar digital vibrating U-tube densimeter (model DMA 5000 M) over the entire composition range from (283.15 to 343.15) K, along with the pure components. The alcoholic solutions investigated included methanol, ethylene glycol, and isopropanol. Excess molar volumes, thermal expansion coefficients, and excess thermal expansion coefficients were calculated using the experimental values. A Redlich–Kister type equation as a function of concentration was fitted with the excess molar volumes for representing the density values of the mixture solutions.

Densities, ultrasonic speeds, viscosities and excess properties of binary mixtures of methyl methacrylate with N,N-dimethylformamide and N,N-dimethylacetamide at different temperatures

The densities, ρ, ultrasonic speeds, u and viscosities, η of binary mixtures of methyl methacrylate (MMA) with N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA), including those of pure liquids, over the entire composition range were measured at temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15)K and atmospheric pressure. From the experimental results, the excess molar volume, VmE, and excess isentropic compressibility, κsE, excess isobaric coefficient of thermal expansion, αpE and excess molar isobaric expansion, Ep,mE were calculated. The excess partial molar volume, V¯m,1E and V¯m,2E and excess partial molar isentropic compressibility, K¯s,m,1E and K¯s,m,2E over the whole composition range; and partial molar volume, V¯m,1° and V¯m,2°, partial molar isentropic compressibility, K¯s,m,1° and K¯s,m,2°, excess partial molar volume, V¯m,1°E and V¯m,2°E, excess partial molar isentropic compressibility, K¯s,m,1°E and K¯s,m,2°E at infinite dilution, and excess partial molar isobaric expansion, E¯p,m,1E and E¯p,m,2E over the whole composition range have also been calculated. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interaction in these mixtures. It is observed that the MMA-DMF/DMA interactions in these mixtures follow the order: DMF<DMA. Further, the viscosities of these binary mixtures were correlated theoretically by using various empirical and semi-empirical models and the results were compared with the experimental findings.

Volumetric and ultrasonic study of mixtures of 2-phenylethanol with 1-butanol, 2-butanol, and 2-methyl-1-butanol at T = (298.15–323.15) K and atmospheric pressure: Measurement and prediction

Densities and speeds of sound for three binary mixtures 2-phenylethanol with 1-butanol, 2-butanol and 2-methyl-1-butanol were measured over the entire range of composition and at six temperatures from 298.15K to 323.15K at 5K interval and atmospheric pressure using a vibrating tube densimeter. Besides, the densities for pure compounds in the above-mentioned temperature range were measured. The experimental densities were used to calculate the excess molar volumes, VmE, isentropic compressibility change, ΔκS, the excess thermal expansion coefficients, αpE and the excess partial molar volumes at infinite dilution, V¯iE,∞. The results have been used to discuss the nature and strength of intermolecular interactions in these mixtures. The values of excess volumes and molar isentropic compressibilites over the entire composition range were negative. The calculated excess and deviations quantities are correlated with the third-order Redlich–Kister equation. Finally the predictive power of a statistically-based equation of state for volumetric properties of the studied mixtures of alcohols has been examined.

Excess thermodynamic parameters for binary and ternary mixtures of {1-butanol (1) + cyclohexylamine (2) + n-heptane (3)} at different temperatures: A theoretical study

In this work, we used the experimental data of Kijevcanin et al. for determining the excess thermodynamic parameters such as excess thermal expansion coefficients αE, isothermal coefficient of pressure excess molar enthalpy (∂HmE/∂P)T and excess partial molar volumes V¯m,iE for the binary and ternary mixtures formed by {1-butanol+cyclohexylamine+n-heptanes} at (288.15–323.15) K. The αE values, for 1-butanol+cyclohexylamine are S-shaped and for 1-butanol+n-heptane are positive and for cyclohexylamine+n-heptane are negative over the mole fraction range. The (∂HmE/∂P)T values, for 1-butanol+cyclohexylamine are S-shaped and for binary mixture of 1-butanol+n-heptane are negative and for binary mixture of cyclohexylamine+n-heptane are positive over the mole fraction. The values of αE and (∂HmE/∂P)T are calculated by using the Flory theory, the results show a good agreement with experimental data. The values of αE and (∂HmE/∂P)T for ternary mixture {1-butanol+cyclohexylamine+n-heptanes} are determined and the experimental data are correlated as a function of the mole fraction by using the equations of Cibulka, Jasinski and Malanowski, Singe et al., Pintos et al., Calvo et al., Kohler, and Jacob–Fitzner. The results show that the Calvo et al. equation is better than others.

Properties of pure n-butylammonium nitrate ionic liquid and its binary mixtures of with alcohols at T = (293.15 to 313.15) K

Values of the density and viscosity of the pure ionic liquid n-butylammonium nitrate (N4NO3) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperature ranging from T=(293.15 to 313.15)K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of N4NO3 were deduced from the experimental density results. The temperature dependence of the viscosity of N4NO3 was fitted to the fluidity equation. Excess molar volumes VE and viscosity deviations Δη for the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. Both excess molar volumes and viscosity deviations show negative deviations for (N4NO3+alcohol) mixtures. The effect of the temperature and the size of the alcohol on the excess molar volumes and viscosity deviations are discussed and analysed. Other derived properties, such as the apparent molar volume, partial molar volume, excess partial molar volume, thermal expansion coefficient, and excess thermal expansion coefficient of the above-mentioned systems were also calculated.

Volumetric and acoustic properties of binary mixtures of cyclohexane + benzene and + benzaldehyde at (293.15–323.15) K

Densities ρ of and speeds of sound u in binary mixtures cyclohexane+benzene and+benzaldehyde have been measured over the entire range of composition at atmospheric pressure and at temperatures ranging from (293.15 to 323.15) K using an Anton-Paar DSA 5000. From these data molar isentropic compressibilities KS,m, thermal expansion coefficients αP, excess molar volumes VmE, and excess molar isentropic compressibilities KS,mE at all the temperatures, and excess thermal expansion coefficients αPE and isothermal pressure coefficient of excess molar enthalpy (∂HmE/∂P)T,x at 298.15K were calculated. The VmE for both the mixtures are positive at all temperatures and over entire range of compositions. The KS,mE are positive over entire composition for cyclohexane+benzene while KS,mE curve is S-shaped for cyclohexane+benzaldehyde. The values of αPE are negative except for cyclohexane rich region in both the mixtures. The values of all the excess functions are lower for cyclohexane+benzaldehyde as compared to cyclohexane+benzene at all the temperatures and compositions.

The excess molar properties of {x1[C6min][BF4] + x22-propanol}: Application of ERAS model

Density, ρ, and viscosity, η, of pure 1-hexyl-3-methylimidazoliumtetrafluoroborate ([C6mim][BF4]), 2-propanol, and binary mixture of {x1[C6mim][BF4]+x22-propanol} were measured at atmospheric pressure and in the temperature range of (293.15 to 333.15) K. The excess molar volume, VmE, thermal expansion coefficient, αp, excess thermal expansion coefficient, αpE, and isothermal coefficient of excess molar enthalpy (∂HmE/∂p)T, x, were calculated from the experimental values of density. The excess molar volumes are negative over the entire mole fraction range for this mixture and increase with increasing temperature. These data have been used to examine the applicability of Extended Real Associated Solution (ERAS) model in correlating the excess molar volume of the binary mixture. The viscosity values of the binary mixture were calculated via McAllister equation and the obtained results show a good agreement between the experimental and the calculated values in the whole composition range and all temperatures, so that the relative deviations are rarely more than 2%. The excess molar properties were correlated with the Redlich–Kister equation.

The theoretical study of effect of temperature on the physicochemical parameters for binary mixtures of vinyl acetate and benzyl acetate, + o-xylene, + m-xylene and + p-xylene

In this work we used the Flory theory of liquid mixtures for determining the thermal parameters such as excess thermal expansion coefficients αE, and isothermal coefficient of pressure excess molar enthalpy (∂HmE/∂P)T,x, of the binary mixtures formed by vinyl acetate and benzyl acetate+o-xylene, or m-xylene, or p-xylene at (303.15 and 313.15)K. From these data the acoustical parameters such as available volume (Va), isothermal (K/), isobaric (K), and isochoric acoustical parameters (K//), isochoric temperature coefficient of the internal pressure (X), and Moelwyn-Hughes parameter (C1), have been calculated. The excess thermal expansion coefficient αE, for the binary mixtures of benzyl acetate+o-xylene and vinyl acetate+m-xylene are negative in x=0.2434 and x=0.9602, respectively, and positive for all mole fractions and increase with increasing temperatures from (303.15 and 313.15)K. The isothermal coefficient of pressure excess molar enthalpy, (∂HmE/∂P)T,x, for vinyl acetate+o-xylene, +p-xylene and benzyl acetate+m-xylene,+p-xylene are negative and decrease with increasing temperatures from (303.15 and 313.15)K. The isothermal coefficient of pressure excess molar enthalpy, (∂HmE/∂P)T,x, for a binary mixture of benzyl acetate+o-xylene is positive and increases with increasing temperatures from (303.15 and 313.15)K.