Isobaric Thermal Expansion Research Articles

Regularities of liquid potassium at different temperatures

Several new regularities in liquid potassium have been found from the existing experimental data and calculated thermodynamic properties along the isothermal lines with the equation of state (EoS) of a power law form. The quantity (Z − 1)V2 is linearly proportional to V2 with a common intersection point for all isotherms at high temperature and PintV versus V−2 is nearly linear, where Z, V and Pint are compressibility factor, molar volume and internal pressure. Both the isothermal bulk modulus and internal pressure are nearly a linear function of pressure at constant temperature. There is a linear relationship existing between the calculated reduced isothermal bulk modulus and V−2. Based on the linear isotherm regularity EoS, analytical expression of thermodynamic properties of liquid potassium can be obtained. Furthermore, we found crossing points existing in the isobaric thermal expansion coefficient and Anderson-Grüneisen parameter.

The (p-Vm-T-x) properties of {water (1) + acetamide (2)} mixtures in the range 278.15–323.15 K and 0.10–100 MPa

The density ρ at atmospheric pressure and compression ratios k=ΔV/Vo of the {water (1) + acetamide (2)} mixture in the range of temperature from 278.15 K to 323.15 K (278.15, 288.15, 298.15, 308.15, 323.15), pressures from 10 to 100 MPa (10, 25, 50, 75 and 100) and in a wide range of compositions (maximum mole fraction of acetamide (AA) x2 = 0.3875) were measured in the work. The partial molar volumes of both components V¯1 and V¯2 in the mixture, molar isothermal compression KT,m, molar isobaric thermal expansion EP,m, isochoric coefficient of thermal pressure βV, and internal pressure of the mixture Pint were calculated. The volume characteristics for an infinitely dilute AA solution in water: limiting partial molar volumes V¯2∞, limiting partial molar isothermal compression K¯T,2∞, and limiting partial molar isobar expansion E¯P,2∞ were calculated. The obtained results are discussed from the standpoint of interactions of solute-solvent and solute-solute. The obtained results are discussed in terms of solute-solvent and solute-solute interactions.

Numerical solutions of compressible convection with an infinite Prandtl number: comparison of the anelastic and anelastic liquid models with the exact equations

We developed a numerical method for the set of equations governing fully compressible convection in the limit of infinite Prandtl numbers. Reduced models have also been analysed, such as the anelastic approximation and the anelastic liquid approximation. The tests of our numerical schemes against self-consistent criteria have shown that our numerical simulations are consistent from the point of view of energy dissipation, heat transfer and entropy budget. The equation of state of an ideal gas has been considered in this work. Specific effects arising because of the compressibility of the fluid are studied, like the scaling of viscous dissipation and the scaling of the heat flux contribution due to the mechanical power exerted by viscous forces. We analysed the solutions obtained with each model (fully compressible model, anelastic and anelastic liquid approximations) in a wide range of dimensionless parameters and determined the errors induced by each approximation with respect to the fully compressible solutions. Based on a rationale on the development of the thermal boundary layers, we can explain reasonably well the differences between the fully compressible and anelastic models, in terms of both the heat transfer and viscous dissipation dependence on compressibility. This could be mostly an effect of density variations on thermal diffusivity. Based on the different forms of entropy balance between exact and anelastic models, we find that a necessary condition for convergence of the anelastic results to the exact solutions is that the product $\unicode[STIX]{x1D716}q$ must be small compared to unity, where $\unicode[STIX]{x1D716}$ is the ratio of the superadiabatic temperature difference to the adiabatic difference, and $q$ is the ratio of the superadiabatic heat flux to the heat flux conducted along the adiabat. The same condition seems also to be associated with a convergence of the computed heat fluxes. Concerning the anelastic liquid approximation, we confirm previous estimates by Anufriev et al. (Phys. Earth Planet. Inter., vol. 152, 2005, pp. 163–190) and find that its results become generally close to those of the fully compressible model when $\unicode[STIX]{x1D6FC}T{\mathcal{D}}$ is small compared to unity, where $\unicode[STIX]{x1D6FC}$ is the isobaric thermal expansion coefficient, $T$ is the temperature (here $\unicode[STIX]{x1D6FC}T=1$ for an ideal gas) and ${\mathcal{D}}$ is the dissipation number.

Anomalous and Not-So-Common Behavior in Common Ionic Liquids and Ionic Liquid-Containing Systems.

This work highlights unexpected, not so well known responses of ionic liquids and ionic liquid-containing systems, which are reported in a collective manner, as a short review. Examples include: (i) Minima in the temperature dependence of the isobaric thermal expansion coefficient of some ILs; (ii) Viscosity Minima in binary mixtures of IL + Molecular solvents; (iii) Anomalies in the surface tension within a family of ILs; (iv) The constancy among IL substitution of Cp/Vm at and around room temperature; (v) ILs as glass forming liquids; (vi) Alternate odd-even side alkyl chain length effects; (vii) Absolute negative pressures in ILs and IL-containing systems; (viii) Reversed-charged ionic liquid pairs; (ix) LCST immiscibility behavior in IL + solvent systems.

High-pressure densities of n-decane+o-xylene mixtures: Measurement and modelling

In this work, the liquid densities of n-decane/o-xylene mixtures were measured at four different component proportions, the mole fractions of n-decane are 0.2001, 0.4065, 0.5835, and 0.8041, respectively. The measurements were performed based on the high-pressure vibrating-tube densimeter, and the measured temperatures were from 283.15 K to 363.15 K and the pressures were from 0.1 MPa to 60 MPa. The Tammann-Tait equation was used to correlate the experimental densities, and the simplified Perturbed Associating Fluid Theory (sPC-SAFT) and Cubic Plus Associating (CPA) equation were used to predict the high-pressure densities of the mixtures with the binary interaction parameters. Derived properties, including isothermal compressibilities and isobaric thermal expansivities, were calculated from Tait equation, sPC-SAFT equation, and CPA equation, respectively. In addition, excess molar volumes of the considered mixtures were obtained and the effects of pressure and temperature on the excess molar volume were discussed.

Characterization and determination of thermodynamic properties of waste cooking oil biodiesel: Experimental, correlation and modeling density over a wide temperature range up to 393.15 and pressure up to 140 MPa

Biodiesel can be described as mono-alkyl esters of long chain fatty acids, derived from a vegetable oil in reactions with alcohols. The physical properties of biodiesel are largely determined by the length of the hydrocarbon chain, the degree of unsaturation, and the effect of molecular packing, while the calculation of the thermodynamic properties of biodiesel is difficult in reason they are high molar weight components and complex structures. The density data (136 points) for waste cooking oil biodiesel at several temperatures between 298.15 K and 393.15 K and pressures up to 140 MPa are reported. The chemical constituents were analyzed by GC/MS, 1HNMR and 13CNMR in order to determine the fatty acid composition of waste cooking oil biodiesel. An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.7 kg m−3 was used to perform these measurements between 298.15 K and 393.15 K. In this work, the density experimental data of biodiesel were correlated with the Tait equation of state (EoS), an empirical equation widely used for high pressure density correlation. The PC-SAFT equation of state using group contribution methods was employed for the calculation of parameters and prediction of biodiesel densities.The statistical parameters of empirical Tait-correlation are much lower than the experimental uncertainty of the density measurements with the AAD (0.01%), MD (0.04%), Bias (7.1 × 10−4%), and standard deviation, σ (1.5 × 10−4g.cm−3), and from PC-SAFT, density of sample was reasonably well predicted with an average relative deviation 0.083%In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

Molecular interactions between some amino acids and a pharmaceutically active ionic liquid domiphen DL-mandelic acid in aqueous medium at temperatures from 293.15 K to 313.15 K

Molecular interactions between some amino acids (glycine, l-alanine, l-valine and l-leucine) and a pharmaceutically active ionic liquid domiphen DL-mandelic acid ([DOM][MAN]) in aqueous solution at various temperatures have been studied by means of volumetric, conductivity and spectroscopy measurements. Density data were used to derive standard partial molar volume, V2,φ0 standard partial molar expansibility, Eφ0, standard transfer volume, ΔtV0, isobaric thermal expansion coefficient, α0 and hydration number, nH of amino acids. On the basis of the experimental conductivity and fluorescence spectroscopy data, the aggregation behaviour of [DOM][MAN] in aqueous amino acid solutions was investigated. Critical micelle concentration, cmc, aggregation number, Nagg, some thermodynamic functions, ΔGm0, ΔHm0, ΔSm0 and ΔCp0 of micellization for [DOM][MAN] have been obtained. Effect of concentration and temperature on the obtained parameters has been discussed. Binding constant Kb for amino acid-[DOM][MAN] complex estimated using the UV–vis spectroscopic data approved that the solute-solvent interactions were strengthened by elevating the size of alkyl part of amino acids.

Volumetric and compressibility properties for aqueous solutions of choline chloride based deep eutectic solvents and Prigogine–Flory–Patterson theory to correlate of excess molar volumes at T = (293.15 to 308.15) K

The thermodynamic properties of deep eutectic solvents (DESs) as neoteric and green solvents are needed to develop and design processes and understand molecular interactions in these type of systems. In this regard, the density (ρ) and speed of sound (u) were measured for aqueous solutions of the DESs based on choline chloride (ChCl) as hydrogen bond acceptor (HBA) with some hydrogen bond donors (HBDs) ethylene glycol (EG), oxalic acid (OA), and malonic acid (MA). On the basis of this data, the excess and deviation molar properties were calculated. In the whole concentration range, the values obtained for excess molar volumes, VE, and isentropic compressibilites deviations, Δκs are negative and that they are increased with increasing the temperature indicating strong interactions between DESs and water. To better undestanding molecular interactions, properties such as excess isobaric thermal expansion (αp, mE), apparent molar volume (Vϕ, 1), and limiting apparent molar expansibility (ϕE, 10) were also calculated. Some equations such as Redlich-Kister and Hwang et al. were used to correlate these properties. Finally, the Prigogine–Flory–Patterson (PFP) theory was used to correlate the excess molar volumes values.

An experimental investigation of molecular interactions between [Emim][triflate] ionic liquid & 2-alkoxyethanols and theoretical comparison by PFP theory

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 (VmE), excess values of partial molar volumes (V¯mE), excess values of isentropic compressibility (κsE), free length (LfE), speeds of sound (uE) and isobaric thermal expansion coefficient (αPE) 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.

Thermal expansion and compressibility of Ca3Al4ZnO10 – an unusual tetrahedral framework structure

Melt-grown single crystals of Ca3Al4ZnO10 have been structurally characterized at ambient conditions (space group Pbcm, a = 5.1364(3), b = 16.7403(9), c = 10.7019(6) Å, V = 920.20(8) Å3, Z = 4, R(|F|) = 0.026 for 1116 reflections with I > 2σ(I) and 95 parameters). Our results show that the compound had been previously described in unnecessarily low symmetry. It represents a three-dimensional network of corner-sharing [(Al,Zn)O4]-tetrahedra containing oxygen atoms simultaneously linking three adjacent tetrahedra. Charge compensation is provided by Ca ions residing in voids of the network. The high-temperature and high-pressure behavior was elucidated between 25(2) and 797(2) °C and between ambient pressure and 6.8(1) GPa. No indications for structural phase transitions have been found. However, a diffraction experiment performed at 9.0(1) GPa gave evidence for the beginning of an amorphization. From the evolution of the lattice parameters thermal expansion and compressibility tensors have been obtained. The behavior of Ca3Al4ZnO10 at non-ambient conditions conforms with the so-called inverse relationship for temperature and pressure, i.e. isobaric thermal expansion and isothermal compression have opposite effects on changes of structural parameters.

Acoustic and volumetric study of renewable oxygenated fuel additives at (298.15–323.15) K: Isomeric butanediols with ethylbutyrate

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, VmE, excess isentropic compressibility, κsE, excess molar isentropic compressibility, Ks,mE, excess speed of sound, uE, and excess isobaric thermal expansion, αpE, 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,1E and V¯m,2E and excess partial molar isentropic compressibilities, K¯s,m,1E and K¯s,m,2E 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 VmE values for these mixtures were also calculated by using Prigogine–Flory–Patterson (PFP) theory and the results were compared with experimental findings.

Investigation of Physico-chemical Properties for the 1-Butyl-3-methylimidazolium Tetrafluoroborate ([Bmim][BF4])–Diethylenetriamine (DETA) System for CO2 Capture

This paper presents the experimental values of densities, viscosities and refractive indices for 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4])–diethylenetriamine (DETA) mixtures over the entire composition range and temperature range 298.15–333.15 K. The physico-chemical properties such as excess molar volume, partial molar volume, partial molar volume at infinite dilution, apparent molar volume, apparent molar volume at infinite dilution, isobaric thermal expansion coefficient and excess isobaric thermal expansion coefficient were calculated from the experimental density data. The excess Gibbs energy and excess entropy of flow were determined from the viscosity data using Eyring’s theory of rate process. The specific interactions between molecules in mixtures were explained by analyzing the behavior of the thermodynamic excess/deviation properties. To determine the correlating accurately with the utilized models including the Redlich–Kister, modified Graber, Lorentz–Lorenz and McAllister equations, the adjustable parameters and standard deviations were determined. Moreover, the qualitative analysis of these properties was further legitimized with Fourier-transform infrared (FTIR) spectroscopic studies.

Thermodynamic and solution properties of sodium valporate in aqueous solution and its interaction with cetyl trimethylammonium bromide (CTAB)

This manuscript reports the volumetric, viscometric and aggregation properties of sodium valporate in aqueous solution. The interaction of drug with cationic surfactant (CTAB) was also studied. From volumetric study, partial molar volume, Hepler's constant, partial molar expansivity and isobaric thermal expansion coefficient were calculated while from viscometric study, the constants of Jones-Dole equation and thermodynamic parameters of viscous flow like free energy change, entropy change and enthalpy change were calculated. Critical micelle concentration of drug at four different temperatures was measured by surface tension and electrical conductivity measurements. The data was used to calculate surface excess concentration and thermodynamic parameters for the micellization process i.e. free energy of adsorption, free energy, entropy and enthalpy of micellization. Spectroscopic study of the drug/surfactant interaction was helpful to calculate partition coefficient, free energy of partition, binding constant and free energy of binding.

Thermophysical Properties of 1-Butyl-3-methylimidazolium Trifluoromethanesulfonate in a Wide Range of Temperatures and Pressures

(p,ρ,T) data of 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][TFO] are reported, obtained using an Anton-Paar DMA HPM vibration tube densimeter. The measurements were conducted at T = (283.15 to 413.15) K and p = (0.101 to 140) MPa. The combined uncertainty at 0.95 level of confidence of a density measurement is estimated up to Uc(ρ) = 0.8 kg·m–3. An equation of state for fitting of the (p,ρ,T) data of [BMIM][TFO] has been developed as a function of pressure and temperature. The equation of state is constructed for the fitted experimentally investigated (p,ρ,T) values, and various thermophysical properties such as isothermal compressibility, isobaric thermal expansivity, thermal pressure coefficient, internal pressure, heat capacities at constant pressure and volume, speed of sound, and isentropic exponent at this temperature and pressure intervals were calculated.

Thermodynamic Relations among Isotropic Material Properties in Conditions of Plane Shear Stress.

We present new general relationships among the material properties of an isotropic material kept in homogeneous stress conditions with hydrostatic pressure and plane shear. The derivation is not limited to the proximity of the zero shear-stress and -strain condition, which allows us to identify the relationship between adiabatic and isothermal shear compliances (inverse of the moduli of rigidity) along with new links, among others, between isobaric and isochoric shear thermal expansion coefficients and heat capacities at constant stress and constant shear strain. Such relationships are important for a variety of applications, including the determination of constitutive equations, the characterization of nanomaterials, and the identification of properties related to earthquakes precursors and complex media (e.g., soil) behavior. The results may be useful to investigate the behavior of materials during phase transitions involving shear or in non-homogeneous conditions within a local thermodynamic equilibrium framework.

Density of biofuel mixtures (Dibutyl ether + Heptane) at temperatures from (298.15–393.15) K and at pressures up to 140 MPa: Experimental data and PC-SAFT modeling

Density has been reported to binary mixtures (552 points) of dibutyl ether (DBE) + heptane in the composition range (4 compositions; 0.325 ≤ dibutyl ether mole fraction x ≤ 0.85), between 298.15,393.15 K, and for 23 pressures ranging from 0.1 MPa to 140 MPa.These experimental measurements were carried out using an apparatus, comprising a vibrating tube densimeter Anton Paar, calibrated with an uncertainty of about 0.7 kg· m-3.The volumetric behavior and excess molar volume of DBE + heptane were modeled using PC-SAFT equation. The PC-SAFT parameters of DBE and heptane were optimized using experimental density data at atmospheric pressure. The density of the mixture was reasonably well predicted, with a mean relative difference between 0.0009% and 1.99%. Whereas the excess molar volume not satisfactorily predicted.A Tait equation was used to adjust the experimental density data. In addition, from this equation the isobaric thermal expansion and the isothermal compressibility were derived.

From mechanics to thermodynamics: A relation between the brittleness and the thermal expansivity for polymers

The isobaric thermal expansivity is an underestimated property. The entire composite structures disintegrate into pieces on heating – without the use of any mechanical force -when the constituents have significantly different expansivities. While one typically tries to relate mechanical properties among themselves and thermodynamic ones among themselves too, we provide an equation relating the linear isobaric expansivity to the brittleness B for a number of polymers with a large variety of chemical structures and consequently with a large variety of properties.

The thermal properties of binary structure sI clathrate hydrate from molecular dynamics simulation

ABSTRACTIn this work, we present temperature dependence of lattice parameter and normalised lattice parameter in the atmospheric pressure and 120 bar and also pressure dependence of unit cell volume and normalised unit cell volume at 150 and 250 K for variety guests with different size, polarity and guest–host hydrogen bonding capability such as trimethylene oxide (TMO), ethylene oxide (EO), formaldehyde (FA), cyclobutane (CB), cyclopropane (CP) and ethane (Et) in the large cages with CH4 in small cages of sI clathrate hydrates by molecular dynamics simulations. The obtained values of lattice parameters for the guest species are compatible with the experimental values. These clathrate hydrates are simulated with TIP4P/ice four-site water potential. Herein, isobaric thermal expansivity and isothermal compressibility are calculated at a temperature range of 50–250 K and a wide pressure range. These structural properties have been compared for guests which they are isoelectronic and have similar masses but with different size and polarity. We use molecular dynamics simulations to relate microscopic guest properties, like guest–host hydrogen bonding to macroscopic sI clathrate hydrate properties. The temperature dependence of thermodynamic properties such as constant-volume and constant-pressure heat capacity is presented in the atmospheric pressure for these guest species.

Thermophysical Study of Binary Systems of tert-Amyl Methyl Ether with n-Hexane and m-Xylene

This work presents the experimentally determined density (ρ), viscosity (η), speed of sound (u), and surface tension (σ) data for tert-amyl methyl ether (TAME) + n-hexane and TAME + m-xylene systems at several temperatures (298.15, 308.15, 318.15, 323.15, and 328.15 K). These experimentally determined thermophysical data are utilized to compute various excess/deviation parameters such as molar volume (VE), isentropic compressibility (κsE), speed of sound (uE), deviation in viscosity (Δ ln η), isobaric thermal expansion coefficient (αPE), and surface tension (σE). The inspection of parameters response may interpret the existing specific molecular interactions as well as the mixing behavior of solutions. The critical analysis of observed parametric behavior have unveiled the strong and weak molecular interactions in TAME with m-xylene and TAME with n-hexane systems, respectively.

Theoretical study of electronic structure, thermoelectric and thermodynamic properties of 2H-AgAlO2

Electronic structure of AgAlO2 have been investigated using first principles calculations based on the full-potential linearized plane-wave method as implemented in WIEN2k package. Generalized gradient approximation (PBESol) and Tran-Blaha modified Becke-Johnson exchange potential (mBJ) are adopted for the treatment of exchange-correlation effects. Calculated electronic properties show the considerable improvement of results with mBJ potential while the strong hybridization between O-2p and Ag-4d states is revealed. From the band structure obtained with mBJ potential, the thermoelectric properties are calculated using semi-classical Boltzmann transport theory. Obtained results suggest that AgAlO2 is a good thermoelectric p-type compound with figure of merit value close to unity at charge-carrier concentration about 1017 (cm−3). Finally, the thermodynamic properties including bulk modulus, isochoric and isobaric heat capacities, thermal expansion and Debye temperature of AgAlO2 also are calculated using quasi-harmonic Debye model and the obtained results are discussed in detail.