Viscosity of biniary mixtures. III. Tri-n-butylamine with alkanes and monoalkylamines at 303.15 and 313.15 K

Viscosities of seven binary systems of n-propylamine, n-butylamine, n-hexylamine, n-octylamine, n-hexane, n-octane, and isoctane (2,2,4-trimethylpentane) with tributylamine have been measured at 303.15 and 313.15 K with an Ubbelohde suspended-level viscometer. Based on Eyring's theory, values of excess Gibbs energy of activation G ^*E of viscous flow have been calculated. Deviations of viscosities from linear dependence on the mole fraction and values of G ^*E are attributed to the H-bonding and to the size of alkylamine and alkane molecules. The free volume theory of Prigogine-Flory-Patterson in combination with work by Bloomfield-Dewan has been used to estimate the excess viscosity ln and the terms corresponding to enthalpy, entropy, and free volume contributions for the present binary mixtures.     

Viscosity of binary mixtures. IV. Triethylamine with alkanes and monoalkylamines at 303.15 and 313.15 K

Viscosities and densities of seven binary mixtures of n-hexane, n-octane, isooctane, n-propylamine, n-butylamine, n-hexylamine, and n-octylamine with triethylamine have been measured at 303.15 and 313.15 K. Deviations of viscosities from a linear dependence on the mole fraction and values of excess Gibbs energy of activation G ^*E of viscous flow are attributable to the H-bonding and to the size of the alkylamine and alkane molecules.     

Excess Volumes, Densities, Speeds of Sound, and Viscosities for the Binary Systems of 1-Octanol with Hexadecane and Squalane at (298.15, 303.15 and 308.15) K

Excess molar volumes, , excess molar isentropic compressibilities, , and deviations of the speeds of sound, u ^D, from their ideal values u ^id in an ideal mixture for binary mixtures of 1-octanol, C₈H₁₇OH, with hexadecane, C₁₆H₃₄, and squalane (2,6,10,15,19,23-hexamethyltetracosane), C₃₀H₆₂, at T = (298.15, 303.15, and 308.15) K and at atmospheric pressure were derived from experimental density, ρ, and speed-of-sound data, u. Viscosity measurements were also carried out for the same mixtures. The Prigogine-Flory-Patterson (PFP) theory has been applied to analyze of these systems. Furthermore, the apparent molar volumes, and apparent molar compressibility, of the components at infinite dilution have been calculated.     

Sound Speeds and Excess Isentropic Compressibilities of Ternary Mixtures of Tetrahydropyran and Aromatic Hydrocarbons at 308.15 K

Speeds of sound, u _ijk , of tetrahydropyran (THP) (i) + benzene (j) + toluene or o- or p-xylene (k), and tetrahydropyran (i)+toluene (j) + o- or p-xylene (k) ternary mixtures have been measured over the entire mole fraction range at 308.15 K and atmospheric pressure. The speed-of-sound data have been used to calculate isentropic compressibilities, (k_S)_ijk{(kappa_S)_{ijk}} , and excess isentropic compressibilities, (k_S^E)_ijk{(kappa_S^{rm E})_{ijk}} . The (k_S^E)_ijk{(kappa_S^{rm E})_{ijk}} values for the investigated mixtures are correlated with the Redlich–Kister equation to estimate ternary adjustable parameters and standard deviations. The Moelwyn–Huggins concept (Huggins, Polymer 12:357, 1971) of interaction between the surfaces of components of binary mixtures has been extended to predict excess isentropic compressibilities of ternary mixtures by employing the concept of connectivity parameters of the third degree of a molecule (which in turn depends on its topology). It has been observed that (k_S)_ijk{(kappa_S)_{ijk}} values predicted by the Moelwyn–Huggins concept compare well with corresponding experimental values.     

Densities, Viscosities, Sound Speeds, and Excess Properties of Binary Mixtures of Methyl Methacrylate with Alkoxyethanols and 1-Alcohols at 298.15 and 308.15 K

The densities, viscosities, and sound speeds were measured for six binary mixtures of methyl methacrylate (MMA)+2-methoxyethanol (ME), +2-ethoxyethanol (EE), +2-butoxyethanol (BE), +1-butanol (1-BuOH), +1-pentanol (1-PeOH), and +1-heptanol (1-HtOH) at 298.15 and 308.15 K. The mixture viscosities were correlated by Grunberg–Nissan, McAllister, and Auslander equations. The sound speeds were predicted by using free length and collision factor theoretical formulations, and Junjie and Nomoto equations. The excess viscosities and excess isentropic compressibilities were also calculated. A qualitative analysis of both of these functions revealed that structure disruptions are more predominant in MMA+1-alcohol than in MMA+alkoxyethanols mixtures. The estimated relative associations are found to become less in MMA+alcohol mixtures than in pure alcohols. The solvation numbers derived from the isentropic compressibility of the mixtures, considering MMA as a solvent, showed that structure making interactions are also present in MMA + alkoxyethanols in addition to the structure disruptions.     

Speeds of Sound and Isentropic Compressibilities of Binary Mixtures Containing Cyclic Ethers and Haloalkanes at 298.15 and 313.15 K

Speeds of sound of binary mixtures formed by either 1,3-dioxolane or 1,4-dioxane and isomeric chlorobutanes at 298.15 and 313.15 K are reported in this paper. Isentropic compressibilities and isentropic compressibility deviations have been calculated from experimental measurements. Isentropic compressibility deviations have been fitted to a Redlich–Kister equation, and the results have been discussed in terms of molecular interactions and structural effects. Isentropic compressibilities have been estimated at 298.15 K using the Prigogine–Flory–Patterson theory.     

Densities and Viscosities of the Quinary System: Cyclohexane (1) + \varvec{m}-Xylene (2) + Cyclooctane (3) + Chlorobenzene (4) + Decane (5) and Its Quaternary Subsystems at 308.15 K and 313.15 K

The volumetric and viscometric properties of the quinary system: cyclohexane + $m$ m -xylene + cyclooctane + chlorobenzene + decane, were measured over the entire composition range at 308.15 K and 313.15 K. The experimental data obtained in the course of the present study were employed to analyze the predictive capability of six semi-theoretical and empirical well-known viscosity models reported in the literature, namely, the generalized McAllister three-body interaction model, the pseudo- binary McAllister model, the group contribution model, the generalized corresponding states principle model, the Allan and Teja correlation, and the Grunberg and Nissan law of viscosity. The predictive capabilities of the models were compared using the percentage average absolute deviation (%AAD). The final results showed that the generalized McAllister model gives the lowest AADs of 3.3 % and 3.7 % at 308.15 K and 313.15 K, respectively.     

Viscosity and Speed of Sound of Gaseous Nitrous Oxide and Nitrogen Trifluoride Measured with a Greenspan Viscometer

The viscosity and speed of sound of gaseous nitrous oxide and nitrogen trifluoride were measured using a Greenspan acoustic viscometer. The data span the temperature range 225–375 K and extend up to 3.4 MPa. The average relative uncertainty of the viscosity is 0.68% for N₂O and 1.02% for NF₃. The largest relative uncertainties were 3.09 and 1.08%, respectively. These occurred at the highest densities (1702 mol · m^-3 for N₂O and 2770 mol · m^-3 for NF₃). The major contributor to these uncertainties was the uncertainty of the thermal conductivity. The speeds of sound measured up to 3.4 MPa are fitted by a virial equation of state that predicts gas densities within the uncertainties of the equations of states available in the literature. Accurate measurements of the speed of sound in both N₂O and NF₃ have been previously reported up to 1.5 MPa. The current measurements agree with these values with maximum relative standard deviations of 0.025% for N₂O and 0.04% for NF₃.     

Thermal Diffusivity, Sound Speed, Viscosity, and Surface Tension of R227ea (1,1,1,2,3,3,3-Heptafluoropropane)

The purpose of the experimental investigations described in the present paper was to carry out an extensive characterization of R227ea (1,1,1,2,3,3,3-heptafluoropropane), a working fluid that has gained increasing importance in refrigeration and air conditioning technology fields. With dynamic light scattering (DLS), a non-intrusive, laser-optical technique, the thermal diffusivity and sound speed of the liquid and vapor phases, as well as the surface tension and kinematic viscosity of the liquid phase, could be determined with high accuracy at saturation conditions, over a wide temperature range starting at 253.15 K and extending to the critical point.Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5–8, 2005, Bratislava, Slovak Republic.     

Viscosity and Density of Methane+cis-Decalin from 323 to 423 K at Pressures to 140 MPa

Dynamic viscosity () and density () data are reported for methane+cis-decahydronaphthaline (decalin) binary mixtures of 25, 50, and 75 mass% (74, 90, and 96 mol%) methane at three temperatures (323, 373, and 423 K) from saturation pressure to 140 MPa. A capillary tube viscometer was used for measuring the dynamic viscosity, with the density being calculated from measurements of sample mass and volume. The overall uncertainties in the reported data are 1.0 and 0.5% for the viscosity and density measurements, respectively.     

Partial Molar Volumes,Viscosity B-Coefficients,and Adiabatic Compressibilities of Sodium Molybdate in Aqueous 1,3-Dioxolane Mixtures from 303.15 to 323.15 K

Partial molar volumes () and viscosity B-coefficients of sodium molybdate in 1,3-dioxolane + water mixtures have been determined from solution density and viscosity measurements at 303.15, 313.15, and 323.15 K and at various electrolyte concentrations. Also, the adiabatic compressibility of different solutions has been determined from the measurement of sound speeds at 303.15 K. The experimental density data were evaluated by the Masson equation, and the derived parameters were interpreted in terms of ion–solvent and ion–ion interactions. The viscosity data have been analyzed using the Jones–Dole equation, and the derived parameters, B and A, have also been interpreted in terms of ion–solvent and ion–ion interactions, respectively. The structure- making or breaking capacity of the electrolyte under investigation has been discussed in terms of the sign of . The compressibility data obtained from sound speeds of different solutions indicate the electrostriction of the solvent molecules around the ions.     

Experimental Study of the Density and Viscosity of n-Heptane at Temperatures from 298 K to 470 K and Pressure upto 245 MPa

The density and viscosity of $n$ -heptane have been simultaneously measured over the temperature range from 298 K to 470 K and at pressures up to 245 MPa using the hydrostatic weighing and falling-body techniques, respectively. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95 % confidence level with a coverage factor of $k= 2$ is estimated to be 0.15 % to 0.30 %, 0.05 %, 0.02 K, and 1.5 % to 2.0 % (depending on temperature and pressure ranges), respectively. The measured densities were used to develop a Tait-type equation of state for liquid $n$ -heptane. Theoretically based Arrhenius–Andrade and Vogel–Tamman–Fulcher type equations with pressure-dependent coefficients were used to describe the temperature and pressure dependences of the measured viscosities for liquid $n$ -heptane. The measured values of the density and viscosity were compared in detail with reported data and with the values calculated from a reference EOS and correlation models for the viscosity.     

Densities, Sound Speeds, Excess Volumes, and Excess Isentropic Compressibilities of Methyl Acrylate + 1-Propanol (or 1-Butanol) + Hydrocarbons(n-Hexane, n-Heptane, Cyclohexane, Benzene, and Toluene) at 308.15 K

Densities and sound speeds of ten ternary mixtures of methyl acrylate (1)+1-propanol (2) or 1-butanol (2)+n-hexane (3), +n-heptane (3), +cyclohexane (3), +benzene (3), and +toluene (3) have been measured at 308.15 K. The excess volumes, V ^E , and excess isentropic compressibilities, ^E _s , have been estimated. These two experimentally derived excess functions were also compared with those predicted by empirical equations of Redlich–Kister, Kohler, and Tsao–Smith. A qualitative analysis of V ^E and ^E _s data of ternary mixtures reveals that in MA (1)+1-alcohols (2)+n-hexane (3), +n-heptane (3), and +cyclohexane (3), structure disruptions are more predominant while in MA (1)+1-alcohols (2)+benzene (3) or +toluene (3) mixtures, the weak but specific structure making interactions dominate. A perusal of deviations between the experimental and calculated V ^E and ^E _s results shows that the predictive expressions give only a rough estimate of the functions for the ten studied mixtures.     

Ultrasonic speeds and densities of poly(dimethylsiloxane) (viscosity grades 30 and 50×10−4 m · s−1) at 298.15, 303.15, and 308.15 K under high pressures

The ultrasonic speeds and densities of poly(dimethylsiloxane), viscosity grades 30 and 50×10^–4 m · s^–1 at 298.15 K, were measured at 298.15, 303.15, and 308.15 K. The measurements were carried out using new apparatuses, one for measurement of the speed under pressures up to 200 MPa and another for measurement of the density under pressures up to 100 MPa. The former is constructed with a sing-around technique of the fixed-path type operated at a frequency of 2 MHz, and the latter is a dynamic bellows piezometer. The probable uncertainty in the present results is within ±0.23% for speed and ±0.19% for density for all the experimental conditions. The ultrasonic speed in these fluids at first increases rapidly with pressure and then indicates a mild rise in the highpressure region. Similar pressure effects are observed for the density. The relationship between the speed and the density satisfied a first-order function well. The isentropic compressibility, derived from the speed and density, also showed a large pressure effect. The values and its pressure effects seemed almost independent of the viscosity of poly(dimethylsiloxane).     

Sound Speed and Density Studies of Interactions Between Cationic Surfactants and Aqueous Gelatin Solution

Studies on the interactions of surfactants with proteins can contribute to an understanding of the action of surfactants as denaturants and as solubilizing agents for membranes of proteins and lipids. Quantitative aspects of such studies may include direct measurements of properties, such as viscosity, density, sound speed, conductance, and elucidation of the often highly complex phase diagrams. In this study, sound speed and density studies of surfactants, viz., cetyltrimethyl ammonium bromide, cetyltrimethyl ammonium chloride, and di(dodecydimethyl ammonium bromide) (12-2-12) have been carried out in a 0.02 % w/v aqueous solution of gelatin at temperatures of 20 °C, 25 °C, 30 °C, and 35 °C. From the measured data, the parameters apparent molar volumes ((f_v){(phi_{v})}), adiabatic compressibility (β), and apparent molar compressibility (f_k){(phi_{k})} have been calculated to interpret the protein–surfactant interactions. The variations in these parameters with the concentration of the surfactant suggests the manifestation of hydrophobic interactions in the system.     

Densities,viscosities, and excess properties of trifluoroethanol-water,tetraethylene glycol dimethylether-water,and trifluoroethanol-tetraethylene glycol dimethylether at 303.15 K

Densities and kinematic viscosities of trifluoroethanol + water, tetraethylene glycol dimethylether + water, and trifluoroethanol + tetraethylene glycol dimethylether have been measured at 303.15 K and atmospheric pressure over the entire range of composition. Dynamic viscosities, excess volumes, excess viscosities, and excess Gibbs energies of activation of flow were obtained from the experimental results. The excess volumes were negative, whereas excess viscosities and energies of activation were positive, presenting the three thermodynamic properties asymmetric composition dependence. The kinematic viscosities were used to test McAllister, Stephan, and Soliman and Marshall correlations.     

Speed of Sound of n-Hexane and n-Hexadecane at Temperatures Between 298 and 373 K and Pressures up to 100 MPa

Measurements of the speed of sound u for n-hexane and n-hexadecane at temperatures of 298.3, 323.15, 348.15, and 373.15 K and at pressures up to 100 MPa are reported. The speeds of sound, the temperatures, and the pressures are subject to an uncertainty of ±0.1%, ±0.01 K, and ±0.2 MPa, respectively. These measurements were undertaken using a new apparatus which has been constructed for measurement of the speed of sound in liquids and supercritical fluids at pressures up to 200 MPa and at temperatures between 248 and 473 K. The technique is based on a pulse-echo method with a single transducer placed between two plane parallel reflectors. The speed of sound is obtained from the difference between the round-trip transit times in the two paths. It is expected that both the precision and the accuracy of the method can be further improved.     

Viscosities of Binary Mixtures of 2-Bromobutane and 2-Bromo-2-Methylpropane with Isomeric Butanols at 298.15 and 313.15 K

This paper reports viscosity data of the binary mixtures (2-bromobutane or 2-bromo-2-methylpropane) plus an isomer of butanol at temperatures of 298.15 and 313.15 K. Kinematic viscosities have been correlated with the equations of McAllister and Heric, and absolute viscosities with the Grunberg–Nissan equation. Viscosity deviations have been correlated by means of a Redlich–Kister type equation, and they give negative values over the complete composition range at both temperatures.     

Thermophysical Properties of Binary Mixtures of Methyl Methacrylate+Di-Ethers (Ethyl, Isopropyl, and Butyl) at 298.15 and 308.15 K

Experimental data for the densities, dynamic viscosities, sound speeds, and relative permittivities and for three binary systems of methyl methacrylate (MMA)+di-ethers (ethyl, isopropyl, and butyl) at 298.15 and 308.15 K and at atmospheric pressure are reported. The mixture viscosities are correlated by Grunberg–Nissan, McAllister, and Auslander equations over the complete composition range. The sound speeds for the mixtures are also calculated by using free length and collision factor theories, and Nomoto and Junjie equations. From the measured primary properties, deviation functions such as deviations in viscosities, sound speeds, relative permittivities, molar polarizations, excess isentropic compressibilities, and molar electrical susceptibilities were calculated, and the compositional dependence of each of the functions was expressed with a Redlich–Kister type equation. The variation of the Kirkwood correlation factor was determined over the complete composition range.