Viscosity Deviations Research Articles

FTIR spectra of pure components and their binary liquid components (Binary mixtures of formamide with aniline, N-methyl aniline and N,N-dimethyl aniline)

Densities (ρ) speeds of sound (u) and viscosities (η) of binary mixtures of formamide (F) with aniline (A), N-methylaniline (NMA)and N,N-dimethylaniline (DMA), including those of pure liquids, over the entire composition range were measured at temperatures (303.15, 308.15 and 313.15) K and 0.1 MPa. Using the experimental data, the excess parameters (VE , κs E ), deviation in viscosity (Δη), excess partial molar volumes, and , and excess partial molar isentropic compressibilities, and of the components at infinite dilution were calculated. The VE results have been analyzed in terms of Prigogine-Flory-Patterson theory. An analysis of each of the three contributions viz. interactional, free volume and P* to VE shows that free volume effects are negative for all the binary mixtures. FT-IR properties have been carried out to study the specific interaction, such as the formation of a hydrogen bond between unlike molecules in the binary liquid mixtures. A good agreement is observed among the excess parameters and FT-IR spectroscopic properties

Densities, viscosities and excess properties for n-nonane with alcohols (C3-C6) from 303.15 K to 333.15 K at atmospheric pressure

The volumetric and viscometric properties of the liquid mixtures are of importance for industrial application and theoretical calculation. This work reports the density and viscosity of the binary mixtures of n-nonane with 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol from 303.15 K to 333.15 K at atmospheric pressure in the whole composition ranges. Excess properties such as excess molar volumes and viscosity deviations were calculated and correlated as the type of Redlich-Kister equation. In addition, the densities and viscosities for the studied mixtures were correlated using PC-SAFT equation and McAllister four-body viscosity model. For n-nonane with 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol mixtures, the average absolute relative deviations between the experimental density data and calculate values from PC-SAFT equation are 0.39%, 0.46%, 0.31%, and 0.38%, respectively. And the average absolute relative deviations of viscosity from McAllister four-body model are 0.82%, 0.86%, 1.32%, and 1.01%, respectively.

Viscometric studies of molecular interactions in binary mixtures of ethylbenzene with (C4 to C8) Alkan-1-ols

Dynamic viscosities (ηexp) for binary mixtures of ethylbenzene with butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol, and octan-1-ol were measured at varying temperatures (298.15–323.15 K; interval, 5 K) and atmospheric pressure. Viscosity deviations (Δη) across the entire range of mole fractions were derived from ηexp and were correlated using a Redlich-Kister type polynomial expression. The ηexp were compared with those calculated, ηcal, in terms of the pure components and the adjustable interaction parameters derived from ηexp using Arrhenius, Kendall-Monroe, Grunberg-Nissan, Teja-Rice, and Andrade/DIPPR models to evaluate the validity of the predictive and correlative approaches. The temperature-induced variations in ηexp were discussed considering the impact of the increasing chain-length of alkanols, including molecular interactions among the component molecules in the binary mixtures. A computational quantum mechanical modeling approach, density-functional theory, was used to explore the dimensions in interactions among the binary mixture components.

Molecular Interactions and Thermophysical Properties of 1, 4 Dioxane with Bromo benzene, Ethyl benzene at various Temperatures via Nonlinear Model

Viscosities and densities of 1,4 dioxane with hydrocarbon bromo benzene, ethyl benzene was measured over the entire mole fractions at temperatures ranging from 303.15, 308.15, and 313.15K. From these experimental results, excess molar volume VE and viscosity deviation ∆η was calculated. The VE and Δη exhibited positive and negative values, respectively, over the entire composition range in the order of 1,4 dioxane+ bromo benzene and < 1,4 dioxane +ethyl benzene systems. The outcomes indicated the weak interactions present in the mixtures. It exists mainly because of the number and position of methyl groups in these aromatic hydrocarbons. The molecular dynamics simulation studies for both the mixtures show no phase separation. The volume occupied by 1,4 dioxane + bromo benzene is lesser than 1,4 dioxane + ethyl benzene substantiating the experimental results of VE and Δη. Standard deviations from the Jouyban–Acree model between the fitting outcomes, and the calculated data are helpful deliberate mixing behavior of the binary mixtures. The molecular interactions existing between the components and comparison of liquid mixtures were also discussed.

Density, Viscosity, and Spectroscopic Nature for the Binary System of Tetraethylene Glycol (1) + Water (2) T = (298.15 to 323.15) K

Densities and viscosities for the binary system of tetraethylene glycol (1) + water (2) at T = (298.15 to 323.15) K were measured as a function of composition under atmospheric pressure. The excess properties, including excess molar volumes ( $$V_{{\text{M}}}^{{\text{E}}}$$ ), viscosity deviations (Δη), and the excess Gibbs free energy of activation for viscous flow (ΔG*E) were calculated by using density and viscosity data, respectively. Excess properties indicated that there are hydrogen bonding interactions between tetraethylene glycol and water molecules, which are investigated in detail by FTIR and UV–Vis spectra.

Spectroscopic, thermodynamic and ultrasonic properties of pseudo‐binary mixtures of organic extractants and vegetable oil at 25–60°C under atmospheric pressure

AbstractThis work is intended to investigate the molecular interactions and transport properties of five pseudo‐binary mixtures of various combinations of vegetable oils (sesame oil and sunflower oil) and organic extractants (Aliquat 336, TBP, D2EHPA and TOA) by determining their surface tension, density and viscosity over a temperature range of 25–60°C at atmospheric pressure. The experimental data are fitted into various literature models. Information on excess molar volume and viscosity deviation leads to an understanding of solute–solvent interactions. Further, the ultrasonic velocity, isentropic compressibility, intermolecular free length, specific impedance, apparent molar volume, volumetric thermal expansion coefficient, excess Gibbs' free energy, change in enthalpy of mixing and entropy of activation of the liquids have been calculated. A model relating the surface tension, density and viscosity of the pseudo‐binary mixtures has been proposed in this paper. Analysis of Fourier transform infrared (FTIR) studies has further illustrated the intermolecular interactions in the pseudo‐binary mixtures.

Solid-liquid equilibrium and kinematic viscosity of binary mixture of fatty acid alkyl esters

The separation and recovery of fatty acid alkyl esters (FAAE) is of great significance for various industries. Crystallization is a well-suited separation process for fatty acid mixtures which may be evolved by the understanding of solid-liquid equilibrium (SLE). The SLE and kinematic viscosity (v) at (T=298.15–318.15 K) and (P=0.1 mPa) for binary mixture of FAAE: methyl decanoate (1)+ethyl decanoate or methyl dodecanoate or methyl tetradecanoate (2) has been studied. The deviation in kinematic viscosity (Δv) data was derived using experimental v data. The measured SLE exhibit general single eutectic point like other organic mixtures. The SLE data fit well with universal quasi-chemical (UNIQUAC) equation. The v values were interrelated using different equations recommended by Heric-Brewer, Krishnan-Ladda, and Lulian et al. Theoretically estimated values using these empirical equations are in accordance with the experimental values with percentage standard deviation less than 0.35. The v were also analyzed by means of the McAllister equation. The Δv data were also fitted with the Redlich-Kister polynomial equation. All three binary mixtures showed negative Δv values.

Optical and viscometric properties for 1-chlorohexane + toluene/tetradecane binary mixtures at temperatures from 298.15 K to 318.15 K and atmospheric pressure

The optical and viscometric properties for two binary mixtures of 1-chorohexane with toluene and tetradecane, were measured at several temperatures in the range of (298.15–318.15) K and atmospheric pressure.The experimental values for refractive indices and viscosities, for both systems were correlated by the Jouyban-Acree model with good accuracy.By using the obtained experimental results, the related excess and deviation quantities, as the deviation in refractive indices, the molar refractions, the deviation in molar refraction and the deviation in viscosities, were calculated and reported in this work. All these excess properties were correlated with the Redlich-Kister polynomial equation.The Lorentz–Lorenz, Gladstone–Dale, Arago–Biot, Edwards, and Eykman predictive equations have been used to calculate the refractive index on basis of measured density, and their accuracy was analyzed.Some different equations: Grunberg–Nissan, Katti Chaudry, Hind, Dolezalek, and three-body McAllister interaction model, were used to calculate the viscosities values and a comparison with those values with the experimental data was made. From the viscosity experimental data, the molar enthalpy of activation and the molar entropy of activation for viscous flow, as well as the excess Gibbs energy of activation for viscous flow, were calculated for both studied binary mixtures.Discussions concerning the experimental and calculated results in relation to the molecular interactions and structural effects between components of mixtures are presented.

Effect of temperature, radiation dose and composition on density, viscosity and volumetric properties of N,N,N′,N′-tetraoctyl diglycolamide (TODGA) and n-dodecane mixture, a promising system for the separation of actinides

The organic solution composed of N,N,N′,N′-tetraoctyldiglycolamide (TODGA) and n-dodecane is extensively studied for the removal of trivalent actinides from the high-level liquid waste arising from nuclear industry. Present work deals with the evaluation of density and viscosity of TODGA/n-dodecane as a function of absorbed gamma radiation dose, temperature and composition. In addition, volumetric and viscometric properties like excess molar volume, apparent molar volume, viscosity deviation, activation energy for the viscous flow, enthalpy and entropy changes of activation of this binary mixture were also estimated. Based on these derived thermodynamic properties, the inter-molecular interactions of this binary liquid solution were predicted. Redlich–Kister type equations were employed to correlate excess volume and viscosity deviation, and the coefficients of fourth degree polynomial that fitted well with the experimental data were estimated. Present study indicated the stable nature of hydrodynamic behaviour of TODGA/n-dodecane system with respect to physical properties up to 500 kGy of absorbed gamma radiation dose.

Thermodynamic Studies on Non-ideal Binary Mixtures of Isoamyl Alcohol and Various Alkanols at 298.15 to 308.15 K

Experimental values of density (ρ), viscosity (η) and speed of sound (u) of five non-ideal binary {solvent + co-solvent} liquid mixture systems, namely isoamyl alcohol (IAA) + ethanol (EA), isoamyl alcohol + 1,2-ethanediol (EDO), isoamyl alcohol + 1,3-propanediol (PDO), isoamyl alcohol + 1,4-butanediol (BDO) and isoamyl alcohol + glycerol (GLY) have been measured over the whole composition range of mole fraction at T = (298.15–308.15) K with 5 K temperature intervals under atmospheric pressure. According to the ρ, η, and u data, the values of excess volume (VE), deviation in viscosity (∆η), and deviation in isentropic compressibility (∆κs) were calculated. The negative values of VE and ∆κs and positive values of Δη obtained for the studied binary liquid systems are indicative of strong intermolecular interactions between unlike molecules. Further, the effects of the number of –OH groups in polyols, as well as the influence of temperature on thermodynamic parameters, were analyzed. Furthermore, the calculated values of VE, ∆η, and ∆κs were correlated with the Redlich–Kister (R–K) model and reasonable standard deviations were obtained.

Volumetric and viscometric properties of binary and ternary mixed alkylamine solutions of 1-dimethylamino-2-propanol, benzylamine and water from 293.15 K to 333.15 K

In this study, the densities and viscosities of the binary solutions 1-dimethylamino-2-propanol (1DMA2P) + H2O, benzylamine (BZA) + H2O, 1DMA2P + BZA and ternary solution 1DMA2P + BZA + H2O were measured at T = (298.15−333.15) K. Furthermore, the volumetric and the viscometric properties including the excess molar volume, partial molar volume, apparent molar volume, limiting apparent molar volume, viscosity deviation, excess Gibbs energy of activation for viscous fluid and Grunberg-Nissan interaction parameters were obtained in terms of experimental data, respectively. The excess molar volumes of binary and ternary solutions were fitted by the Redlich-Kister equation and Cibulka equation, besides, the viscosity and viscosity deviation of binary solution were correlated by using the Grunberg-Nissan equation and Redlich-Kister equation. Moreover, the intermolecular interactions were analyzed based on the volumetric and viscometric properties of solutions.

Insight into structural properties and molecular interactions of maline (choline chloride + malonic acid) and 1, 4- butanediol based pseudo-binary mixture: A thermophysical, spectral, and simulation portrayal

The current study elucidate the thermophysical, spectral, and simulation depiction of the prepared deep eutectic solvent (DES) named as maline comprising of an equimolar mixture of choline chloride (ChCl) as hydrogen bond acceptor (HBA) and malonic acid (MA) as hydrogen bond donor (HBD) in the presence of 1, 4-butanediol (BTD) as other HBD (cosolvent). Various thermophysical properties viz., (densities, ρ, speeds of sound, u, viscosity, η and refractive index, nD) were comprehended for the examined pseudo-binary (maline and BTD) mixtures as a function of composition and temperature. The derived thermophysical properties viz., excess molar volume, VmE, excess isentropic compressibility, κsE, excess intermolecular free length, LfE, deviation in viscosity, Δη, and deviation in molar refraction, ΔRM were found to be negative while the excess speed of sound, uE, excess acoustic impedance, ZE, and deviation in refractive index, ΔnDwere found to be positive which signified the favourable hydrogen bonding interactions between maline and BTD. The partial molar volumes, V¯m,1, V¯m,2 and excess partial molar volumes, V¯m,1o and V¯m,2o of the components at infinite dilution exhibited the negative value due to the contraction in volume over the entire concentration thereby strengthening the presence of specific interaction. The molecular interaction in the examined pseudo-binary system conferred in terms of excess parameters with composition and temperature have also been correlated using the Redlich-Kister (R-K) equation. The significant shifting in the spectral profile as observed from FT-IR (Fourier-transform infrared) spectroscopy evidently inferred the favorable inter-molecular interaction within the maline and BTD based pseudo-binary mixture. A noteworthy change in the chemical shifts as deduced from1H- and 13C- NMR (Nuclear Magnetic Resonance) spectral peaks confirmed the hydrogen bonding networks between maline and BTD. Additionally, the 2D 1H–1H COSY (correlation spectroscopy) outcomes exposed the degree of variation in the inter-molecular interactions and structural arrangement between maline and BTD system. The spectral results were further validated employing theoretical (computational simulation) analysis which accounted the extensive hydrogen bonding from the evaluated computed descriptors Also, the 3D-molecular electrostatic potential (3D-MEP) explicated the effect of charge delocalization in the proximity of hydrogen bonding networks.

Binary System of Polyethylene Glycol 200 (1) + 3-Dimethylamino-1-propylamine (2) for CO2 Absorption: Thermophysical Properties and Spectroscopic Study.

As the concentration of CO2 in the atmosphere keeps increasing, the development of a highly efficient CO2 absorbent is highly desired. In this work, a binary mixture system of polyethylene glycol 200 (PEG 200) (1) + 3-dimethylamino-propylamine (DMAPA) (2) was used for CO2 absorption. Considering the importance of thermophysical properties to binary solutions, the densities and viscosities of the PEG 200 (1) + DMAPA (2) mixture were measured at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K and atmospheric pressure over the entire composition range. Based on the density and viscosity data, the excess properties and viscous flow thermodynamic parameters were calculated, respectively. To obtain the coefficients and to estimate the standard deviations between the experimental and calculated quantities, the excess molar volume (VmE), the viscosity deviation (Δη), and the excess Gibbs free energies of activation for viscous flow (ΔG*E) were fitted to the Redlich–Kister equation. Furthermore, based on the results of UV–vis, FTIR, and 1H NMR spectra, the intermolecular interaction of PEG 200 and DMAPA was discussed. Particularly, a strong intermolecular bonding is formed when the molar ratio of PEG 200 to DMAPA is about 1:2 because of the excess molar volume (VmE). On that account, a mixture of PEG 200 and DMAPA in a ratio of 1:2 was used for studying CO2 absorption, and a CO2 absorption of about 0.19 g per gram of absorbent was achieved at room temperature and atmosphere.

Concentration Dependence of the Viscosity Activation Energy of Aqueous Ethylene Glycol Mixtures

Mixtures of ethylene glycol with water are a prominent example of media with variable viscosity, and ethylene glycol molecules serve as a prototype of various polyols having multiple hydroxyl groups. The dynamic viscosity of ethylene glycol–water mixtures was measured by vibro-viscosimetry over entire range of mole fraction under atmospheric pressure and from 10 to 30 °C; the variation of the viscosity activation energy with ethylene glycol mole fraction was determined and is discussed. In the present work we propose a novel equation for modeling the concentration dependences of the activation energy and viscosity. The theory is based on the assumption that the nonlinear characteristics can be associated with some structural changes of the mixtures, and that the reaction kinetics can be applied to this breakdown. The Grunberg–Nissan parameter and viscosity deviations were calculated. The possible changes in the variety of complexes for different concentration ranges is discussed. Correlation between the activation energy and pre-exponential factor was made. Three concentration regions are determined, separated by ethylene glycol molar fractions x = 0.11 and 0.43, where the structure of the water/ethylene glycol complexes changes.

Density and viscosity of CO2 + ethyl acetate binary systems from 308.15 to 338.15 K and 15 to 45 MPa

Combined with a high-pressure vibrating-tube densimeter and capillary viscometer, the density and viscosity of CO2(1)+ethyl acetate(2) binary systems with x2 = 0.000, 0.036, 0.075, 0.117, 0.163, and 1.000 were measured under conditions of 308.15–338.15 K and 15–45 MPa. In addition, the volumes of mixing (ΔVm) and viscosity deviation (Δη) were also calculated. The results illustrate that the density and viscosity of all systems increased with decreasing temperature and increasing pressure. The viscosity of the binary systems increased with increasing ethyl acetate concentration, and the density reached a maximum point under high pressure conditions (40 and 45 MPa). Moreover, ΔVm was negative and found to be reduced with a temperature decrease and pressure increase. Δη was positive except for pressures at 15 MPa, and these were found to be improved when increasing the temperature and pressure. The PC-SAFT equation of state and the Toscani-Szwarc model were applied to predict and correlate the density of the systems. For viscosity, different types of models were used. The Chung-Lee-Starling model and TRAPP model were introduced to predict pure systems, the Song mixing rule was used for mixed system viscosity correlation, and the Baylaucq equation was applied for unitary and binary system viscosity correlation. Four types of statistical values (AAD, bias, SDV, and RMS) were used to evaluate these models for each system.

Insight into intermolecular interactions in benzonitrile + methyl acrylate/ethyl acrylate/n-butyl acrylate/t-butyl acrylate binary mixtures at temperatures from 293.15 to 318.15 K: Ultrasonic and viscometric study

The ultrasonic speeds, u and viscosities, η of binary mixtures of benzonitrile with alkyl acrylate (methyl acrylate, ethyl acrylate, n-butyl acrylate and t-butyl acrylate) over the entire composition range, including the pure liquids, were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and at pressure, p = 101 kPa. From the experimental data, the excess isentropic compression, κsE, excess ultrasonic speed, uE, excess molar isentropic compression, Ks, mE and deviations in viscosity, Δη have been calculated. The excess properties were correlated by the Redlich-Kister polynomial equation. The partial molar isentropic compressions and excess partial molar isentropic compressions over the whole composition range; and partial molar isentropic compressions and excess partial molar isentropic compressions of the components at infinite dilution have also been calculated. The variations of these parameters with composition and temperature have been discussed in terms of intermolecular interaction prevailing in these mixtures. Further, the η data of these mixtures were theoretically correlated with various empirical and semi-empirical models and the results were compared with the experimental data.

Significance of the inconstant viscosity and internal heat generation on the occurrence of Darcy-Brinkman convective motion in a couple-stress fluid saturated porous medium: An analytical solution

In this analysis, the collective effect of temperature-reliant viscosity and internal heat generation on the appearance of convective motion in couple-stress fluids saturated a thin porous layer is investigated employing linear stability principle. The significant influences of viscosity deviation parameter Q, internal heat generation parameter HS, couple-stress parameter Cs and Darcy number Da on the stability of the arrangement are obtained analytically and presented graphically in term of the critical thermal Darcy-Rayleigh number Rt,c. Below the critical values, no convective motion arises in the considered system. It is recognized that the viscosity deviation parameter Q and internal heat generation parameter HS have destabilizing effect, while the couple-stress parameter Cs and the Darcy number Da show stabilizing effect on the stability of the fluidic system. By increasing the couple-stress parameter Cs from 0.2 to 0.4 and the Darcy number Da from 0.25 to 0.50, the critical thermal Darcy-Rayleigh number Rt,c increased approximately 21% and 51%, respectively.

Thermodynamic and spectroscopic properties of binary liquid mixtures of 2-methylcyclohexanone and o- substituted anilines at various temperatures

ABSTRACT The densities (ρ), viscosities (η), and speeds of sound (u) are reported for binary mixtures of 2-methylcyclohexanone with ortho-substituted anilines (2-chloroaniline, 2-methylaniline and 2-methoxyaniline) over the entire composition range from 303.15 K to 313.15 K and at atmospheric pressure 0.1 MPa. The excess functions and deviation in viscosity were calculated from the densities, speeds of sound, and viscosities at experimental temperatures. FT-IR properties have been carried out and analysed to study the presence of specific interaction such as the formation of hydrogen bonding of the type (O-H·····N or N-H·····O) between unlike molecules in the binary liquid mixtures, a good agreement is observed among the excess parameters and FT-IR properties.

Densities and viscosities for binary mixtures of dimethyl carbonate with 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol

In this work, the density and viscosity data for binary mixtures of dimethyl carbonate with 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol were presented from 303.15 K to 333.15 K at atmospheric pressure over different concentration ranges. The density and viscosity measurement was carried out based on the vibrating-tube densimeter and Ubbelohde capillary viscometer, respectively. Derived properties, such as excess molar volumes and viscosity deviations, were calculated from the experimental values, and were correlated based on the Redlich-Kister equation. In addition, excess molar volumes and viscosity deviations of the studied mixtures were analyzed and compared with other DMC/1-alcohols mixtures reported in the literatures.

Excess thermodynamic properties and FT-IR studies of binary mixtures of 2-butoxy ethanol + amines at different temperatures

Experimental values of density (ρ), speed of sound (u) and viscosity (η) of binary liquid mixtures containing 2-butoxy ethanol with dipropylamine, diethylamine and triethylamine at temperatures (298.15 to 308.15) K with the interval of 5 K have been discussed in the present communication. Using the experimental data, thermodynamic parameters like excess molar volume (VmE), excess isentropic compressibility (κsE), excess speed of sound (uE), deviation in viscosity (Δη), excess Gibb’s free energy of activation (ΔG*E), apparent molar volume (Vφ,i) and partial molar volume (V¯m,i) have been calculated to study the interaction present in these liquid mixtures. Strong intermolecular interaction between the components of the mixtures is made known by these parameters. Order of magnitude of these parameters substantiates the order of interaction of 2-butoxy ethanol with amines. Redlich-Kister polynomial has been used to correlate the excess and deviation properties with composition. To carry out comparison of correlating ability of various viscosity models, standard deviation has been calculated using the corresponding relation. Spectral data of these liquid mixtures also strengthens the results obtained from above calculated thermodynamic properties.