Experimental Density Values Research Articles

Electrical Transport Properties and Gamma-Ray Attenuation Coefficient of Some Phosphate Glasses Containing By-Pass Cement Dust

Some phosphate glasses containing different amounts of by-pass cement dust (BCD) were prepared by the melt quenching method. The selected molecular composition was [(100-x)% - P2O5 (x)% BCD (where 30≤ x≥60)]. The obtained experimental density and molar volume values were inspected and were then compared with those obtained empirically for the close packed structure of the corresponding compounds. The comparison between experimental and emperical values evidenced the short range order of the studied samples. The electric and dielectric properties were thoroughly investigated. The appearance of maxima and minima in the total conductivity BCD concentration dependence can be attributed to the mixed alkali – alkaline earth effect (MAAE) and to the presence of considerable amount of CaO. The suitability of such glasses to act as gamma-ray shielding materials was thoroughly investigated, and correlation between the chemical composition (the BCD concentration) and gamma-ray attenuation behavior was established.

Densities, Viscosities, Refractive Indices, and Excess Properties of Aqueous 1,2-Etanediol, 1,3-Propanediol, 1,4-Butanediol, and 1,5-Pentanediol Binary Mixtures

The thermodynamic and transport properties of aqueous alkanediol systems at atmospheric pressure were studied over the whole concentration range using the experimental values of density and refractive index at temperatures of 288.15–318.15 K with 5 K interval and viscosity at T = 293.15, 298.15, and 303.15 K. The obtained data were compared with those available in literature. A detailed analysis regarding the behavior of aqueous alkanediols and interactions between the mixture components was performed using different excess thermodynamic properties. Moreover, McAllister model and Grunberg–Nissan and its new proposed models were applied to predict the viscosity data. The validity of the proposed equations was assessed by comparisons between the experimental values and those obtained by the models.

Liquid density, viscosity and spectroscopic studies of binary mixture of tetraethylene glycol + 1,2-ethanediamine for CO2 capture

ABSTRACTThermophysical properties for binary mixture of tetraethylene glycol (T4EG) (1) + 1,2-ethanediamine (EDA) (2), a potential scrubbing solution for the absorption of CO2, are very important as well as lacking in the literatures. This work reports densities and viscosities over the entire concentration range for the binary mixture at T = (293.15-318.15) K under atmospheric pressure. According to the experimental density and viscosity values, the mixtures’ excess molar volume (VmE), absolute viscosity deviation (∆η), excess free energies of activation (∆G*E), apparent molar volumes, partial molar volumes and isobaric thermal expansion coefficient were calculated, respectively. Meanwhile, the VmE, ∆η and ∆G*E values were fitted by a Redlich–Kister equation to obtain coefficients. To further study, the Fourier transform infrared, UV-Vis and fluorescence spectra of T4EG + EDA mixtures with various concentrations were measured, and the intermolecular interaction of T4EG with EDA was also discussed as the formation of –OCH2CH2O–H···N(H2)CH2CH2(H2)N···.

A GEP based model for prediction of densities of ionic liquids

Abstract One of the most important properties of ionic liquids (ILs) is their densities. Accurate knowledge of this property is required in engineering and scientific purposes including equipment design, liquid metering calculations, and other applications. As a result, it is important to develop accurate and effective models for prediction of this property. The present work aims to develop a model based on Gene Expression Programming (GEP) technique for prediction of experimental density values of 146 different ionic liquids at different temperatures. A databank containing 602 data gathered from the literature was utilized to develop the model. The input parameters of the model are temperature, molecular weight of IL, normal boiling point temperature of IL, critical pressure of IL, critical volume of IL, and acentric factor of IL. The outcomes of this work indicate that the developed model is capable of estimating target density data with an acceptable accuracy. The effectiveness and accuracy of the model were checked by utilizing different statistical and graphical techniques. Moreover, results of the proposed model are compared with predictions of literature correlations and it is shown that the GEP model is effectively superior to other correlations and exhibits higher accuracy and reliability.

Physical Properties of the Pure Deep Eutectic Solvent, [ChCl]:[Lev] (1:2) DES, and Its Binary Mixtures with Alcohols

[ChCl]:[Lev] (1:2) DES was synthesized in the laboratory with choline chloride, and levulinic acid, in a 1:2 relationship, stirring both components at 333.15 K and at 101.3 kPa. A thermophysical study of the pure [ChCl]:[Lev] (1:2) DES was realized. Densities, speeds of sound, dynamic viscosities, and refractive indices of the pure [ChCl]:[Lev] (1:2) DES are measured in the temperature range (293.15–343.15 K) and at 101.3 kPa of pressure. Density and refractive index data were additionally used to calculate other properties such as thermal expansion coefficient and molar refractions for the pure DES. The experimental values of density, speed of sound and refractive index showed a linear relationship with temperature, while the viscosity data were fitted using common equations such as Arrhenius, Vogel–Fulcher–Tamman (VFT), Litovitz, and fluidity. Besides, this paper reports experimental data, at different temperatures T = (298.15, 308.15 and 318.15) K, of density, speed of sound, refractive index, and visc...

Link between Density and Molecular Structures of Energetic Azido Compounds as Green Plasticizers

In this study a new correlation for predicting the density of energetic organic azido compounds through multiple linear regression method is proposed. The methodology assumes that the density of energetic azido compounds is a function of optimum elemental composition and several molecular structure descriptors. The new proposed correlation is derived on the basis of experimental density values of 38 energetic azido compounds with different molecular structure as training set. The determination coefficient of the new correlation is 0.971. Also, it has the root mean square deviation (RMSD) and the average absolute deviations (AAD) of 0.044 and 0.035 g·cm–3 respectively. In addition, the correlation gives good predictions for further 9 energetic azido compounds as test set. The predictive ability of the correlation is checked using a cross validation method (Q2LMO = 0.973). Also, the predicted densities of 5 energetic azido compounds are compared to those of the based complex quantum mechanical methods. The proposed method can also apply for designing novel energetic azido compounds.

High pressure densities and derived thermodynamic properties for the (n-heptane + n-octane + ethanol) ternary system

The density of the ternary system (n-heptane+n-octane+ethanol) at temperatures from (293.15 to 373.15)K and at pressures from (0.1 to 40)MPa was experimentally determined at twelve compositions and the results are presented here. Measurements were performed using high pressure U-tube cell DMA HP coupled with DMA 5000 vibrating density meter. To fit the experimental density values the modified Tammann-Tait equation was applied. Excess molar volumes were also calculated at all pressures and temperatures in order to explain to what extent the investigated mixtures deviate from ideal behaviour. Moreover, the influence of pressure and temperature on density was studied by calculating isothermal compressibility and isobaric thermal expansion coefficient. It was found that non-ideal behaviour of the ternary mixture is strongly influenced by pressure and temperature conditions.

Synthesis, thermophysical properties and COSMO-RS study of DBU based protic ionic liquids

In the present work, a new series of DBU based protic ionic liquids has been synthesized. The anions were generated from acetic acid, trifluoro acetic acid, methane sulfonic acid and trifluoro methanesulfonic acid. The obtained [DBU][Ac], [DBU][Tfa], [DBU][Msa] and [DBU][Tfmsa] ionic liquids were characterized by 1H NMR and 13C NMR. The neat ILs were used to determine thermophysical properties namely density (ρ), viscosity (η) surface tension (γ) at various temperature ranges and atmospheric pressure (0.1MPa). The experimental density and viscosity values were correlated using the linear and Vogel-Tammann-Fulcher (VTF) equations, respectively. Furthermore, thermal expansion coefficient (α) molar volume (Vm), thermodynamic surface properties and critical temperatures were estimated from experimental results. The lattice potential energy (UPOT) of the ILs was calculated to estimate the strength of ionic interactions between ions. In addition, the effect of water content on experimental results was measured and also estimated. The theoretical model namely COSMO-RS was used to study the ionic interactions in synthesized ionic liquids. Finally, the experimental and calculated results were discussed to understand the effect of temperature and moiety of ionic liquid on the thermophysical properties studied.

Physicochemical study of solute-solute and solute-solvent interactions of aqueous binary mixtures of l-alanine methyl ester hydrochloride and l-valine methyl ester hydrochloride at different temperatures: Volumetric and compressional studies

Amino acids are the building blocks of proteins and their study provides important information, which can be related to the behavior of larger biomolecules such as proteins. The present article reports experimental values of density (ρ) and speed of sound (u) of aqueous binary mixtures of biologically important amino acid derivatives, namely, l-alanine methyl ester hydrochloride and l-valine methyl ester hydrochloride at different temperatures i.e. T=(278.15, 288.15 and 298.15)K within the concentration range of (0–0.16)mol·kg−1. The obtained data of densities and speeds of sound of solutions were processed to obtain different derived parameters, such as apparent molar volume of solute (Vϕ), isentropic compressibility of solution (κs) and apparent molar isentropic compressibility of solute (κϕ). The limiting values of apparent molar volume of solute (Vϕ0), apparent molar isentropic compressibility of solute (κϕ0), apparent molar expansivity (Eϕ0) of solute, coefficient of thermal expansion (α∗), hydration number (nH) and second derivative of limiting apparent molar volume (∂2Vϕ0/∂T2) have also been computed. The results have been interpreted in terms of various interactions occurring among solute and solvent molecules and structure making and structure breaking tendencies of the solute in these aqueous binary systems.

Investigation on molecular interactions of antibiotics in alcohols using volumetric and acoustic studies at different temperatures

The density and sound velocity for pure alcohols (methanol, ethanol, iso-propanol and n-butanol) and molal solutions of nitroimidazoles (metronidazole (MNZ) and dimetridazole (DMZ) have been measured at different temperatures (293.15–313.15K). Different volumetric and acoustical parameters like apparent molar volume (Vϕ), partial molar volume (V˚ϕ), apparent molar isentropic compressibility (Kϕ), partial molar isentropic compressibility (K˚ϕ), hydration number (nH), acoustic impedance (Z) and intermolecular free length (Lf) of antibiotic solutions were calculated from the experimental values of density and sound velocity. The derived values have been used to explore the solute–solute and solute–solvent interactions. The Vϕ values are positive and Kϕ values are negative in both antibiotics, indicative of strong solute–solvent interactions and closely packed structure of antibiotics in alcohols. The decreasing trend of Lf with increasing antibiotic concentration shows the presence of strong intermolecular interactions in solutions.

Investigations on molecular interaction of some amino acids with the drug levofloxacin in aqueous solution by volumetric and acoustic methods at different temperatures

Apparent molar properties (V∅ and K∅,s) of amino acids (glycine, L-alanine and L-valine) within the concentration range of (0.02–0.20)mol·kg−1inaqueous (0.005, 0.01and0.03)mol·kg−1 Levofloxacin (LVFX) solutions are computed from the experimental density (ρ) and ultrasonic speed (c) values at T=(288.15, 293.15, 298.15, 303.15and308.15)K and P=0.1MPa. Derived parameters such as partial molar properties (V∅0 and K∅,s0) and their experimental slopes (SV and SK), transfer partial molar properties (ΔV∅0 and ΔK∅,s0), hydration numbers (nH) and Hepler’s constant are computed from the data of apparent molar properties. The pair and triplet interaction coefficients have also been evaluated from transfer parameters. The linear variation of V∅0 with the number of carbon atoms in the alkyl chain of amino acids has been utilized to calculate the contribution of the charged end groups (NH3+,COO-), (CH2) group and other alkyl chains of the amino acids to V∅0. From the obtained parameters, some information in regard with the solute-solvent interaction in the systems studied was obtained. The co-sphere overlap model was used to interpret the positive transfer properties (ΔV∅0 and ΔK∅,s0). The volume and compression data suggest that there exist strong solute-solvent interactions in these systems, which increase with increase in temperature. It is inferred that amino acids studied act as structure-breaker (chaotropic effect) in aqueous LVFX solutions.

Prediction of the boiling temperature of 1,2-dimethoxyethane and propylene carbonate through the study of viscosity–temperature dependence of corresponding binary liquid mixtures

ABSTRACTCalculation of excess properties in 1,2-dimethoxyethane (DME) + propylene carbonate (PPC) binary liquid mixtures at (298.15, 308.15 and 318.15) K from experimental viscosity and density values was presented in earlier work. Investigations of these experimental values to test correlation quality of different equations as well as their corresponding relative functions were also reported. Considering the quasi-equality between the enthalpy of activation of viscous flow ΔH* and the viscosity Arrhenius activation energy Ea, here, we can define partial molar activation energy and for DME with PPC, respectively, along with their individual contribution separately. Correlation between Arrhenius parameters brings to light interesting Arrhenius temperature with a comparison to the temperature of vaporisation in the liquid vapour equilibrium, and the limiting corresponding partial molar properties that can permit us to predict value of the boiling points of the pure components. New empirical equations for estimating the boiling temperature are proposed.

PρT measurement and PC-SAFT modeling of N,N-dimethyl formamide, N -methyl formamide, N,N-dimethyl acetamide, and ethylenediamine from T = (293.15–423.15) K and pressures up to 35 MPa

The PρT data of N,N -dimethylformamide (DMF) and N,N-dimethylacetamide (DMA) were measured at temperature range of (293.15–413.15) K and pressures up to 30 MPa. The same properties also were measured for N-methylformamide (NMF) and ethylenediamine (EDA) over the temperature range within (293.15 to 423.15) K and (293.15–383.15) K and at pressures up to 35 MPa and 30 MPa, respectively. The measurements at 10 K intervals and along eight isobars were done. The experimental density values were correlated with the Tait equation. Based on the obtained result, other thermodynamic properties, such as, isothermal compressibility, κT, thermal expansion coefficient, αP, and thermal pressure coefficient, γV, were calculated. Also, the PC-SAFT model was used to correlate the densities of the pure solvents at the above-mentioned temperature and pressure range. In general, both models yield comparable and satisfactorily good correlation of the high pressure and temperature density.

A new interlayer potential for hexagonal boron nitride

A new interlayer potential is developed for interlayer interactions of hexagonal boron nitride sheets, and its performance is compared with other potentials in the literature using molecular dynamics simulations. The proposed potential contains Coulombic and Lennard-Jones 6–12 terms, and is calibrated with recent experimental data including the hexagonal boron nitride interlayer distance and elastic constants. The potentials are evaluated by comparing the experimental and simulated values of interlayer distance, density, elastic constants, and thermal conductivity using non-equilibrium molecular dynamics. The proposed potential is found to be in reasonable agreement with experiments, and improves on earlier potentials in several respects. Simulated thermal conductivity values as a function of the number of layers and of temperature suggest that the proposed LJ 6–12 potential has the ability to predict some phonon behaviour during heat transport in the out-of-plane direction.

Measurements and correlations of density, viscosity, and vapour-liquid equilibrium for fluoro alcohols

The measurements of density, viscosity for 2,2,3,3-tetrafluoro-1-propanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol are reported at different temperatures and pressure of 101.3kPa. The experimental values of densities and viscosities of the above two fluoro alcohols were correlated successfully by a second-order polynomial and by a Vogel–Tammann–Fulcher equation, respectively. Meanwhile, isobaric vapour-liquid equilibrium results for two binary systems of (methanol+2,2,3,3,4,4,5,5-octafluoro-1-pentanol) and (2,2,3,3-tetrafluoro-1-propanol+2,2,3,3,4,4,5,5-octafluoro-1-pentanol were determined by a modified Rose type still. Both the Herington area method and the van Ness point to point test method were adopted to confirm the thermodynamic consistency of the experimental VLE findings, for which the test results showed good thermodynamic consistency. The Wilson and non-random two-liquid (NRTL) activity coefficient models were used to correlate the measured VLE values at different temperatures. The correlation results indicate good agreement with the experimental values. Also the binary interaction parameters of the two activity coefficients models were regressed. With the calculation of GE, the negative deviation behaviour was observed for the two binary systems.

Static permittivity, density, speed of sound, and refractive index of 2-propoxyethanol mixtures with water in a wide temperature range

The static permittivity, εr, density, ρ, speed of sound, u, and refractive index, nD, of water+2-propoxyethanol mixtures were measured over the entire range of mixture composition in a wide temperature range. The experimental values of density and speed of sound were used to determine the molar volume, Vm, adiabatic compressibility, βS, and their excess values. Also the values of partial molar volumes V‾1 and V‾2 as well as the thermodynamic parameters namely the entropy derivative after pressure, ∂S/∂p, enthalpy derivative after pressure, ∂H/∂p and molar heat derivative after pressure, ∂C/∂p of the mixtures were determined.The experimental data of static permittivity were used to determine deviations from the additivity of permittivity, Δεr, excess of this value, εrE, temperature coefficient of permittivity, ∂lnεr/∂T, and their excesses, (∂lnεr/∂T)E.Using the results of refractometric analysis and static permittivity, the values of Kirkwood’s correlation factor, gK, and their excess values, gKE, were also determined.The concentration and temperature dependent results of the mixtures were used in the analysis of hydrogen bond interactions occurring between the molecules of water and 2-propoxyethanol.

Studies on Thermodynamic and Transport Properties of Binary Mixtures Containing Alcohols and Aniline

Experimental values of density and viscosity were measured for pure aniline, 2-propanol, 2-butanol, and 2-pentanol, along with their binary mixtures with aniline over the entire range of mole fraction at the temperatures 293.15–323.15 K. Excess molar volumes and viscosity deviation were calculated from the experimental data of density and viscosity and show negative values for all binary mixtures. Free-volume theory was coupled with the PC-SAFT model for calculation of viscosities of pure fluids and their binary mixtures. In all cases, this model is provided satisfactory performance, and the maximum of average absolute deviation is 2.38%.

Explosive decomposition of pentaerythritol tetranitrate pellets containing nickel nanoparticles with various radii

The kinetics of the explosive decomposition of pressed pentaerythritol tetranitrate pellets containing nickel nanoparticles with various radii has been investigated experimentally, with the explosion initiated by a neodymium laser pulse (wavelength, 1064 nm; pulse duration at half-height, 14 ns), and probability curves for this process have been recorded. The experimental values of critical initiation energy density corresponding to 50% explosion probability are 0.9, 0.7, and 1.4 J/cm2 at a nickel particle radius of 67, 78, and 138 nm, respectively. The initial time interval in which the intensity of light emission accompanying the explosive decomposition increases begins during the action of the pulse and is described by a Gaussian function with an effective constant of k = (1.4 ± 0.1) × 108 s–1, which is independent of the nanoparticle radius. Experimental data of this study can be interpreted within the micro-hotspot model of thermal explosion.

Interactions of 1,2,3-trialkylimidazolium-based ionic liquids with γ-butyrolactone

Experimental densities and viscosities for γ-butyrolactone (GBL) binary mixtures with 1,2,3-trialkyl-substituted imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, namely: 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide [emmim][NTf2], 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide [pmmim][NTf2] and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide [bmmim][NTf2] (p=0.1MPa) in the temperature range from T=(293.15–323.15)K over the whole composition range. From the experimental density data the related excess molar volumes were calculated and fitted using Redlich-Kister’s polynomial equation. The thermal expansion coefficients were also calculated from the acquired experimental density values. The influence of C-2 methyl group and effects of the alkyl side chain length of the 1,2,3-trialkylimidazolium ionic liquids on the nature of interactions and hydrogen bonding in the studied binary mixtures with GBL were discussed. Volumetric and transport properties of GBL binary mixtures with selected ILs are compared with available literature data for the corresponding 1,3-dialkyl-supstituted imidazolium based ionic liquids.

Solvation behaviour of an antihelmintic drug in aqueous solutions of sodium chloride and glucose at different temperatures

The experimental values of densities (ρ), speeds of sound (u) and relative viscosities (ηr) of piperazine citrate in aqueous solution and in 0.06mol·kg−1 of sodium chloride and d-glucose as a function of concentration have been obtained at T/K=(293.15, 303.15 and 313.15). The thermodynamic parameters such as apparent molar volume (Vϕ) of solute, isentropic compressibility (κs), apparent molar isentropic compressibility (κϕ) of solute, piperazine citrate in water and in aqueous solutions of sodium chloride and d-glucose have been computed using the density and speed of sound data. The limiting apparent molar volume of solute (Vϕ0), limiting apparent molar compressibility (κϕ0) in binary and ternary solution have been obtained using apparent molar volume and apparent molar compressibility data. The limiting apparent molar expansivity (Eϕ0) of solute and thermal expansion coefficient (α∗) in both aqueous binary and ternary solutions has been computed. Transfer volumes (ΔtrVϕ0) and transfer compressibilities (Δtrκϕ0) of piperazine citrate from water to aqueous solutions of sodium chloride and d-glucose at different temperatures have been obtained. The Jones-Dole viscosity coefficients A, B, D, variation of viscosity B coefficient with temperature i.e. dB/dT, hydration number for aqueous solutions of piperazine citrate and in aqueous solutions of sodium chloride and d-glucose have been determined. The above parameters have been used to throw light on the various interactions occurring between binary and ternary systems.