Excess Molar Isentropic Compressibility Research Articles

A study on thermophysical properties of binary mixtures of n-hexane with benzene and some alkyl-substituted benzenes within temperature range (293.15–323.15) K: Experimental and modeling approach

The current work reports densities and sound speeds, and related thermodynamic excess properties, namely excess molar volumes and excess isentropic compressibilities, measured at temperatures from (293.15 to 323.15) K and under atmospheric pressure conditions for binary mixtures of n-hexane with benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Redlich-Kister polynomial correlated the thermodynamic excess properties to test the quality of experimental data. Excess properties contributed to understanding molecular interactions between involved molecules and the peculiarities of their packing in the mixture. The Jouyban-Acree model was used to correlate the mixtures' experimental densities, sound speeds, and their related derived properties, namely isobaric thermal expansivities and isentropic compressibilities. The average absolute percentage deviation of the correlated values from the experimental ones was better than 0.036 %, 0.058 %, 0.040 %, and 0.146 % for density, sound speed, isobaric thermal expansivity, and isentropic compressibility, respectively, attesting to the robustness of the Jouyban-Acree correlations. Additionally, the Perturbed Chain Statistical Associating Fluid Theory Equation of State modeled the densities of the current mixtures. Schaaff's Collision Factor Theory and Nomoto's relation were compared for their ability to model the sound speeds of the mixtures. The efficacy of these models was tested by computing the average absolute percentage deviations between experimental and computed values. The modeled densities are reasonably concordant with experimental data, with an overall deviation of 0.02 %. Notably, Nomoto's relation exhibited superior performance over Schaaff's theory in modeling sound speeds of current mixtures, with an overall deviation of 0.33 %. The current findings underline the efficacy and versatility of the used models for thermodynamic modeling in systems of varying complexity.

Density, Speed of Sound and Derived Properties of Binary Mixtures Propiophenone + Butoxyethanol at T = (303.15, 308.15, 313.15 and 318.15) K

The current study reports the experimental density (ρ) and sound speed (u) values for binary mixes of liquids propiophenone + 2-butoxyethanol at atmospheric pressure (0.1 MPa) and T = (303.15, 308.15, 313.15 and 318.15) K for the full spectrum of composition. densities and sound speed measurements from experiments have been used to estimate excess isentropic compressibility (κsE), excess molar volume (VEm), excess molar isentropic compressibility (KEs,m), excess isobaric thermal expansivity (αEp) and excess sound speed (uE). The Redlich-Kister polynomials were used to correlate excess parameters. Excess partial molar volume quantities (VEm,1 and VEm,2) at infinite dilution and their limiting values (V0Em,1 and V0Em,2) have been analytically determined using Redlich-Kister polynomials from the experimental density data. The results have been analyzed in light of strength and interactions among molecular entities scope and extent prevalent in these mixtures.

Density and speed of sound of (iodobenzene + n-alkane) liquid mixtures at T = (288.15 to 308.15) K. Application of the Prigogine-Flory-Patterson model

(Iodobenzene + n-alkane) liquid mixtures have been studied experimentally, in terms of densities (ρ) and speeds of sound (c), and theoretically, by the application of the Prigogine-Flory-Patterson (PFP) model. The n-alkanes considered are n-heptane, n-decane, n-dodecane, and n-tetradecane. ρ and c measurements have been performed at a pressure p = 0.1 MPa and in the temperature range T = (288.15 to 308.15) K. Excess molar volumes (VmE) and excess isentropic compressibilities (κSE) have been calculated and correlated by Redlich-Kister polynomials. (∂VmE/∂T)p curves at the same (p,T) conditions have been obtained from correlated VmE values. The mixtures are characterized by the following features: (i) VmE increases with the number of carbon atoms of the n-alkane (n), being negative for n = 7, small and S-shaped with positive and negative values for n = 10, and positive for n = 12 and n = 14; (ii) κSE and (∂VmE/∂T)p are negative, increase with n and are very close to zero for n = 14. From these experimental results and the knowledge of the excess molar enthalpies of mixtures containing fluorobenzene, chlorobenzene or bromobenzene with n-alkanes, we have inferred the presence of structural effects, especially important for n = 7 and less relevant for volumetric properties as n increases. The VmE obtained are compared with those of other (halogenated benzene + n-alkane) liquid mixtures existing in the literature, namely systems with fluorobenzene, chlorobenzene, and bromobenzene. From this comparison and the analysis of the isobaric thermal expansion coefficients of the pure compounds, it is inferred that the interactional effects on VmE do not vary appreciably with the length of the n-alkane, so the observed VmE variation is fundamentally determined by the corresponding variation of the contribution from structural effects. Moreover, the application of the PFP model supports this interpretation, providing free volume contributions to VmE that vary parallelly to VmE with the length of the n-alkane, and interactional contributions that rest approximately constant independently of the n-alkane size.

Volumetric and acoustic studies of binary mixtures of DEC with isomeric chlorobenzene at various temperatures

ABSTRACT Densities, ρ, and speeds of sound, u, of binary liquid mixtures of diethyl carbonate with 1,2-dichlorobenzene, 1,3-dichlorobenzene and 1,2,4-trichlorobenzene have been measured over the entire range of composition at 303.15 K, 308.15 K, 313.15 K and 318.15 K and at atmospheric pressure. From the experimental data of the density and speed of sound, the excess properties such as excess molar volume, V m E , excess isentropic compressibility, κ s E , excess molar isentropic compressibility, K s , m E , excess speed of sound, u E , and excess isobaric thermal expansion, α p E , have been calculated. For better knowledge of the solute and solvent interaction, excess partial molar volumes, V ˉ m , 1 E and V ˉ m , 2 E , and excess partial molar volumes, V ˉ m , 1 ∘ E and V ˉ m , 2 ∘ E of the components at infinite dilution have been measured. All the excess parameter values have been fitted using the Redlich–Kister polynomial smoothing equation. The calculated excess values have been analysed in terms of molecular interactions and structural effects.

Acoustic and volumetric study of binary mixtures containing Ethyl propionate with amides at various temperatures

The development of biofuels to replace fossil fuels has recently increased at an exponential rate. Many chemical molecules with a wide range of functional groups make up biofuels. There is a strong correlation between the interactions between these molecules and the performance of biofuels. In this paper, the authors presented the new findings related to interactions existing in ethyl propionate and Formamide(F), N-Methylformamide (NMF), and N, N-Dimethylformamide (DMF) in a 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 expansivity, 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 excess partial molar volume, V¯m,1E, V¯m,2E , excess partial molar isentropic compressibility, K¯s,m,1EK¯s,m,2E over the whole composition range together with partial molar volume, V¯m,10, V¯m,20, partial molar isentropic compressibility K¯s,m,10, K¯s,m,20, excess partial molar volume, V¯m,10E, V¯m,20E and excess partial molar isentropic compressibility, K¯s,m,10E,K¯s,m,20E at infinite dilution have also been calculated from the experimental density measurements and analytically obtained using Redlich-Kister polynomials. The variations of these parameters with changes in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures.

Influence of alkyl chain length and temperature on the densities, viscosities and speeds of sound of binary liquid mixtures of {2-methyl-1-butanol + 2-ethoxyethanol, or 2-propoxyethanol, or 2-butoxyethanol} at T = (298.15, 303.15 and 308.15) K

Density (ρ), viscosity (η) and speed of sound (u) of pure components and binary mixtures of 2-methyl-1-butanol with alkoxyethanols viz., 2-ethoxyethanol, 2-propoxyethanol and 2-butoxyethanol have been measured over the entire range of composition at different temperatures T = (298.15, 303.15 and 308.15) K. Using the experimental data various thermophysical properties such as excess molar volume (VmE), excess molar isentropic compressibility (Ks,mE), excess speed of sound (uE), deviation in viscosity (Δη) and excess Gibb’s free energy of activation for viscous flow (ΔG∗E) have been calculated. The excess or deviation properties used to define the molecular interactions between like and unlike components. Further, the values of excess and deviation properties have been fitted to the Redlich-Kister polynomial equation. The measured viscosities have been correlated with various semi-empirical relations such as Grunberg-Nissan, Tamura-Kurata, Hind et al., Katti-Chaudhri, McAllister (three body interaction) model, Heric-Brewer and McAllister (four body interaction) model. Apart from this, Prigogine–Flory–Patterson (PFP) theory is also used for the estimation of VmE values for studied binary mixtures.

Study of molecular interactions in binary mixtures of 2-ethyl-1-hexanol with primary alcohols (propan-1-ol, 2- propen-1-ol and 2- propyn-1-ol) at various temperatures

ABSTRACT The densities (ρ), viscosities (η), and speeds of sound (u) were reported for binary mixtures of 2-ethyl-1-hexanol with aliphatic primary alcohols (propan-1-ol, 2-propen-1-ol, 2-propyn-1-ol) over the entire composition range from 303.15 K to 313.15 K and at atmospheric pressure 0.1 MPa. The excess parameters (VE,κs E), deviation in viscosity, excess partial molar volumes, ( and ) excess partial molar isentropic compressibility’s ( and ) of the components at infinite dilution were calculated from the densities, speeds of sound, and viscosities at experimental temperatures. The variation of these properties with composition of the mixtures suggests hydrogen bond and charge-transfer complex formation between 2-ethyl-1-hexanol and self-associated primary alcohols. The VE results have been analysed in the light of Prigogine-Flory-Patterson theory. An analysis of each of the three contributions, namely, interactional, free volume and P* to VE shows that interactional contribution was positive for all binary systems. The free volume effect and P* contribution were negative for all the mixtures. Furthermore, the FTIR spectra have been recorded at 298.15 K and found to be useful for understanding the presence of hydrogen bonding between dissimilar molecules in the liquid mixtures. A good agreement was obtained between excess quantities and spectroscopic data.

Experimental, theoretical, computational and spectroscopic analysis in binary liquid mixtures containing 1-propanol and C-1 to C-4 alkyl acetates (T = 298.15–318.15 K): Physicochemical properties and molecular interaction studies

The molecular interactions between 1-propanol (1P) (1) and alkyl acetates (AAc) (C1-C4) (2) were examined by understanding of thermophysical properties of given binary liquid mixtures. Density (ρ), viscosity (η) and speed of sound (u) were measured for 1P, AAc and their binary mixture at T = 298.15–318.15 K with interval of 5 K at 0.1 MPa. Experimental data of ρ, η and u were used to evaluate VmE (excess molar volume), uE (excess ultrasonic speed), Δη (deviation in viscosity), ksE (excess molar isentropic compressibility), G∗E (excess Gibbs free energy of activation of viscous flow), VfE (excess free volume), LfE (excess intermolecular free length) and VaE (excess available volume) and correlated with R.K. (Redlich-Kister polynomial) equation. VmE data was also examined in term of Graph theoretical approach (GTA) and Prigogine-Flory-Patterson (PFP) theory. Δη were analyzed by Bloomfield and Dewan model (BFD) and also examined in terms of Graph theoretical approach (GTA). The u data was examined by different correlations like Van Dael, Nomoto, JFLT (Jacobson’s free length theory), Impedance dependence and CFT (Schaaff’s collision factor theory). FT-IR spectroscopic studies provide important information for understanding the intermolecular interactions between 1P (1) and AAc (2) components in the binary mixture which is also recognized by GTA. Further, DFT studies indicated the strength of molecular interactions and supported the graph theory in predicting probable associative molecular species in the liquid mixtures.

Study of molecular interactions of monoethanolamine with some higher alcohols at 298.15 K

Abstract Experimental measurements of the viscosity, density, and ultrasonic parameters of monoethanolamine (MEA) with 1-butanol, 1-pentanol, and 1-hexanol were carried out at 298.15 K. The excess molar volume (V E), viscosity change (Δη), and isentropic compressibility (ΔK s) are calculated using the viscosity, density, and ultrasonic velocity data. A polynomial equation of the Redlich-Kister type was used to fit these values. With increasing mole fraction, the viscosity, the density and the ultrasonic velocity increase. As the concentration of MEA rises, the excess molar volume falls. All V E values for MEA and 1-hexanol are positive, meaning that V E increases. At all concentrations, isentropic compressibility and viscosity change exhibit negative values.

Analysis of thermo-physical properties and qualitative investigation of molecular interactions in terms of Graph Theoretical Approach in binary liquid mixtures containing 1-propanol + Amines (1,3-diaminopropane or 1,2-diaminopropane or 1-amino-2-propanol) at T = 298.15–318.15 K

In the present report, the molecular interactions between 1P (1-propanol) and Amines (1,3-DAP (1,3-diaminopropane) or 1,2-DAP (1,2-diaminopropane) or 1A2P (1-amino-2-propanol)) are examined by insight of thermo-physical properties of binary liquid mixtures. Density (ρ) and speed of sound (u) were measured for 1P, Amines and their binary mixture at T = 298.15–318.15 K at 0.1 MPa. Experimental data of ρ and u were used to evaluate VmE (excess molar volume), ksE (excess molar isentropic compressibility), VfE (excess free volume), uE (excess ultrasonic speed), LfE (excess intermolecular free length) and VaE (excess available volume). Further, these calculated properties were correlated with Redlich-Kister polynomial (R.K.). VmE data is also examined in term of GTA (Graph theoretical approach) and PFP (Prigogine-Flory-Patterson) theory. FT-IR spectroscopic studies supported the results and clearly indicated that a strong intermolecular interactions exist between 1P and Amines components in the binary mixture which is also recognized by GTA. The u data were examined by different correlations like Nomoto, Impedance dependence, Van Dael, JFLT (Jacobson’s free length theory) and CFT (Schaaff’s collision factor theory).

Insights into experimental and theoretical approach to physicochemical properties of aqueous PEGylated deep eutectic solvents at T=(293.15–323.15) K

This paper demonstrates the excess molar properties: excess molar volumes VmE and excess isentropic compressibilities Ks,mE of aqueous binary mixtures of PEGylated DESs at T = (293.15 - 323.15) K and at atmospheric pressure. The DESs were prepared from combination of Tetrabutylammonium bromide/Benzyltributylammonium chloride as HBA with Polyethylene glycols of different average molar masses 200, 400, and 600 as HBD. The excess molar properties excess molar volumes VmE and excess isentropic compressibilities Ks,mE of DESs binary mixtures were obtained over the entire composition range from experimental values of the density and speed of sound of both pure and aqueous DES mixtures. The Redlich-Kister equation was used to estimate the standard deviation between experimental and calculated excess properties. The stronger interaction between water and components of studied DESs gave negative values for both excess molar properties. This behaviour of the investigated systems was assessed using Extended Real Associated Solution Model (ERAS) and Prigogine-Flory-Patterson theory (PFPT). The obtained results were interpreted in terms of interactions between the mixture components, temperature, structure of HBA and molecular mass of HBD.

Molecular interaction analysis of 1-amino-2-propanol with alkyl acetate (C1-C4): Volumetric, acoustic, isentropic compressibility (T = 298.15–318.15 K) and IR spectroscopic investigations

In the present report, density (ρ) and speed of sound (u) of binary mixtures 1A2P (1-amino-2-propanol) (1) + AAc (2) (MAc (methyl acetate), EAc (ethyl acetate), PAc (propyl acetate) and BAc (butyl acetate)) mixture were calculated at T = 298.15–318.15 K at 0.1 MPa. Based on experimental data different thermo-physical properties like excess molar volume (VmE), excess molar isentropic compressibility (ksE), excess free volume (VfE), excess ultrasonic speed (uE), excess intermolecular free length (LfE) and excess available volume (VaE) were evaluated and also correlated with Redlich-Kister polynomial (R.K.) equation. The obtained result were interpreted in terms of structural and molecular interactions between the mixing components. The effects of steric hindrance and temperature on the excess properties are discussed. In addition, the various correlations like Nomoto, Impedance dependence, Van Dael, Jacobson’s free length theory (JFLT) and Schaaff’s collision factor theory (CFT) were employed to analyze the u data. Further, FT-IR spectroscopy studies clearly indicate that a strong intermolecular hydrogen bonding exist between 1A2P and alkyl acetates components in the binary mixture.

Densities and Sound Speeds of Ternary Mixtures Methyl tert-Butyl Ether + Toluene + n-Hexane (or Cyclohexane) and Their Binary Subsystems at a Temperature of 298.15 K and under Ambient Pressure

Densities ρ and sound speeds c of the ternary systems methyl tert-butyl ether (MTBE) + toluene + n-hexane, MTBE + toluene + cyclohexane, and related binary subsystems MTBE + toluene, MTBE + n-hexane, toluene + n-hexane, MTBE + cyclohexane, and toluene + cyclohexane are measured over the whole composition range at 298.15 K and under ambient pressure. The excess molar volumes, VmE, and isentropic compressibility deviations, ΔκS, were derived from experimental ρ and c data. The experimental results are discussed in terms of the possible interactions between molecules in the mixture and structural effects. The VmE and ΔκS data for the binary and ternary systems were correlated with the Redlich–Kister and Cibulka equations, respectively. Further, the ternary VmE and ΔκS data are compared with the predicted values using the binary contribution models of Radojković, Kohler, Rastogi, Tsao-Smith, Toop, and Scatchard. The root-mean-squared deviation between experimental and predicted values is used as a tool to measure the predicting capabilities of the tested models.

Study of intermolecular interactions in binary mixtures of methyl acrylate with benzene and methyl substituted benzenes at different temperatures: An experimental and theoretical approach

• Reports new u and η data of methyl acrylate + aromatic hydrocarbons mixtures. • The study provides estimation of excess properties of these mixtures. • Provides information on nature and relative strength of interactions in these media. • Various empirical and semi-empirical models are used to correlate viscosity data. • The scaled particle theory (SPT) is used to predict ultrasonic speed theoretically. The ultrasonic speeds, u and viscosities, η of the binary mixtures of methyl acrylate with benzene, toluene, o -xylene, m -xylene, p -xylene, and mesitylene over the whole mole fraction range were measured at six different temperatures and at atmospheric pressure. From the experimental data, the excess isentropic compressibility, κ s E , excess ultrasonic speed, u E , excess molar isentropic compressibility, K s,m E , excess specific impedance, Z E and deviations in viscosity, Δ η have been calculated. The partial molar isentropic compressions, K ¯ s,m,1 and K ¯ s,m,2 , and excess partial molar isentropic compressions, K ¯ s,m,1 E and K ¯ s,m,2 E over the whole composition range, partial molar isentropic compressions, K ¯ s,m,1 ̂ and K ¯ s,m,2 ̂ , and excess partial molar isentropic compressions, K ¯ s,m,1 ̂ E and K ¯ s,m,2 ̂ E of the components at infinite dilution have also been calculated. The results specified the existence of weak interactions between unlike molecules, and these interactions follow the order: benzene > toluene > p -xylene > m -xylene > o -xylene > mesitylene. The magnitude of interactions was found to be dependent on the number and position of the methyl groups in these aromatic hydrocarbons.

Excess Thermodynamic Properties of Ethyl Acetate with Primary Alcohols At 303.15 K

Densities (ρ) and sound velocity (u) for the binary mixtures of ethyl acetate with 1-methanol, 1- ethanol, 1- propanol, 1- butanol, 1-hexanol and 1-octanol were measured over the entire composition range at 303.15 K. From these data, excess molar volume (VE), isentropic compressibility (Ks ) and deviation in isentropic compressibility (ΔKs ) have been calculated with the Redlich-Kister Polynomial equation. The experimental data were discussed in terms of intermolecular interactions between component molecules.

Volumetric and Acoustic Properties of Binary and Ternary Mixtures of Butanol Isomers with Gasoline Surrogate Compounds

Substituting butanol, a renewable fuel for internal combustion engine, as the gasoline blend against the conventionally used ethanol requires the knowledge of their thermophysical properties as these properties decide the fuel injection system, flame propagation, and combustion process in a compression ignition engine. Butanols offer higher energy density and lower tendency to absorb moisture. To offer proof of concept of the influence of temperature and composition of various organic solvents in the isomers of butanol, herein, we had experimentally measured the values of densities (ρ) and speeds of sound (u) of butanol isomers with o-xylene, toluene, and 2,2,4-trimethylpentane at different temperatures (T = 298.15 and 308.15 K) and at 101.3 kPa pressure and over the entire composition range. Measured data have been used to calculate the thermodynamic properties, namely, excess molar volumes VmE and excess molar isentropic compressibilities Ks, mE. The behavior and influence of the temperature and proportion of butanol isomers on measured and calculated properties were studied. Experimental VmE data have been fitted to the Redlich–Kister polynomial equation, and standard errors in prediction were determined. Densities of the binary system are predicted by the PC-SAFT equation of state. We further have used the Prigogine–Flory–Patterson (PFP) theory to predict VmE of the studied systems. Results of predicted and experimentally determined VmE over the entire range of proportion of butanols are compared. Influence of isentropic compressibility on the resulting fuel’s combustion characteristics has been cursorily discussed.

Experimental Study and Modeling Using the PFP Theory and the ERAS Model of the Excess Molar Volume and Isentropic Compressibility of Dimethylbenzylamine with Alkanol Mixtures at Different Temperatures

Experimental Study and Modeling Using the PFP Theory and the ERAS Model of the Excess Molar Volume and Isentropic Compressibility of Dimethylbenzylamine with Alkanol Mixtures at Different Temperatures

Optimization of Thermo-Physical Properties For The Binary System Of Acetone–Water At 303.15-318.15 K By Response Surface Quadratic Model

Thermo bodily residences of binary liquid combos are very beneficial in biotechnology, pharmaceutical, chemical and petroleum refining industries for improved favoured products from diverse raw materials. The physical property data on mixed solvents are important for the theoretical and applied areas of research and are frequently used in many chemical and industrial processes such as design of new process and process equipment (fluid flow, mass transfer or heat transfer calculation) and designing of bioreactor/fermenter. The objective of the current paper is to determine the density, viscosity, ultrasonic velocity, refractive index and surface tension of acetone (1) + water (2) at temperatures of 303.15K to 318.15K for the complete composition degrees and atmospheric pressure. These experimental values were used to calculate the respective excess homes in conjunction with a few acoustic properties. The experimental facts and excess residences have been used to calculate the interacting coefficients and well known deviations from different existing models. Also the new model equations have been evolved with the aid of the use of Design Expert application for density, viscosity, ultrasonic velocity, refractive indices and surface tension. Experimental consequences have been analysed on the premise of molecular interactions among element molecules with the assistance of FT-IR spectrum. Acetone-water binary structures of the prevailing observer have positive values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which suggests sturdy interactions among the components of binary mixtures. Thermodynamic observations of acetone and water mixtures were made. Negative viscosity deviation of acetone-water combinations suggests robust dipole-dipole interactions within the device. Fourier remodel infrared spectroscopy also indicates the sturdy interaction made at 3589 cm-1 and based on the response surface method outcomes, more interplay takes area at zero. Five and zero six moles of acetone and water combination and the consequences are conformed with reference to the R2 cost (0.89). Excess molar extent and isentropic compressibility were decided and kinds of interactions have been discussed primarily based on the derived properties.

Understanding of the interactions between azole-anion-based ionic liquids and 2-methyl-3-butyn-2-ol from the experimental perspective: the cage effect.

The interactions between azole-anion-based ionic liquids (AILs) and 2-methyl-3-butyn-2-ol (MBY) play an important role in AIL-promoted carboxylative cyclization of MBY with CO2. To better understand the interactions between AILs ([P66614][Im], [P66614][4-MeIm], and [P66614][4-BrIm]) and MBY, a detailed investigation from the experimental perspective has been carried out in this study. The results show that the derivative of viscosity (η) with the mole fraction of AIL (xAIL) of AIL + MBY mixtures appears to have the maximum value when xAIL ≈ 0.3, while 1H NMR chemical shifts of P-CH2 of [P66614]+ reach the minimum value at xAIL ≈ 0.3, indicating that [P66614]+ of AILs tend to self-aggregate. The interaction parameters (gji-gii) of the systems obtained from η by the Eyring-UNIQUAC equation are positive, and the difference between the bulk and local composition (xi-xii) is always negative, indicating that AILs can interact with MBY. Moreover, excess molar volumes and isentropic compressibility deviations are all negative deviations and become more negative as the temperature increases, reaching a minimum value at xAIL ≈ 0.30, indicating that azole-based anions can form H-bonds with MBY, and MBY molecules tend to enter the aggregates formed by AILs. Consequently, the cage effect is proposed to describe the interactions between AILs and MBY: MBY first enters the cage formed by the aggregation of [P66614]+, and then forms H-bonds with azole-based anions. Finally, the sizes of the particles of the [P66614][Im] + MBY mixture from dynamic light scattering increase first and then decrease with xAIL, with the maximum of 122 nm at xAIL ≈ 0.25, which confirms the rationality of the cage effect.

Thermo-physical properties of 1,3-Diaminopropane + alkyl acetate (C1-C4) liquid mixtures: Investigation of molecular interactions by insight of IR spectroscopy and DFT studies

The density (ρ) and speed of sound (u) data of 1,3-Diaminopropane (1,3-DAP) (1) + alkyl acetate (AAc) (C1-C4) (2) mixtures at the temperatures (298.15, 303.15, 308.15, 313.15, and 318.15) K and pressure 0.1 MPa were measured. ρ and u data have been used to calculate excess molar volume (VmE), excess molar isentropic compressibility (ksE), excess ultrasonic speed (uE), excess free volume (VfE), excess available volume (VaE) and excess intermolecular free length (LfE). The result of speed of sound have been analyzed in term of various correlations like Nomoto, Van Dael, Impedance dependence and Schaaff's collision factor theory at temperature 298.15 K. The calculated deviation and excess properties are well fitted with Redlich-Kister polynomial equation and further results were analyzed with the help of the structural, inter and intramolecular interaction aspects. IR spectra of the liquid mixture supported the intermolecular interaction between the 1,3-DAP and AAc molecules through shifting of the position of the stretching frequency of some specific functional groups. The results obtained from DFT studies clearly indicates the formation of strong intermolecular interaction between 1,3-DAP and AAc.