Volumetric and ultrasonic properties of ionic liquid (IL) with molecular solvents are important parameter for elucidation of solute-solute and solute-solvent interactions occurring in solutions. In the present work, the density, ρ and speed of sound, u for binary solutions of the protic ionic liquid (1,8-diazabicyclo [5.4.0] undec-7-en-8-ium trifluromethane sulfonate), with molecular solvents like water and ethanol have been measured as a function of molality in temperature range (293.15 to 318.15) K and at atmospheric pressure. From the experimental data, apparent molar volume, Vφ, apparent molar isentropic compression, Ks,φ and limiting apparent molar expansion, Eφ ∞ have been calculated. Further, to understand the extent of interaction between studied IL and solvents the apparent molar properties at infinite dilution were analyzed by using Redlich-Mayer type equation. © 2017 Elsevier B.V.

Ramesh L. Gardas

Department Of Chemistry

K. J. Jisha

Dharmendra Singh

Gyanendra Sharma

Atmospheric pressure

Compressibility of liquids

Organic solvents

Volume measurement

APPARENT MOLAR ISENTROPIC COMPRESSIONS

APPARENT MOLAR PROPERTIES

Apparent molar volume

Effect of temperature

Isentropic compressibility

REDLICH-MAYER EQUATION

SOLUTE-SOLVENT INTERACTION

ULTRASONIC PROPERTIES

Ionic liquids

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IIT Madras

Journal of Molecular Liquids

In the maneuver to achieve desulfurization, we have explored various nitro-substituted positional isomeric imidazolium-based aprotic ionic liquids (ILs). Ortho-, meta-, and para-substituted nitro benzyl group-aided imidazolium-based ILs were synthesized and used to understand the extractive desulfurization (EDS) efficiency of fuels. ILs chosen for the experiment were optimized using the B3LYP method and 6-311(++)g(d,p) of Gaussian 09, and their interactions with thiophene derivatives were analyzed using the integrated electric field polar continuum model solvation. Free energy of solvation provided qualitative information about the ability of ILs to achieve desulfurization. Parameters affecting the efficiency of synthesized ILs were perused, such as the effect of IL volume, concentration, duration of rotation, and other such parameters. Lewis acidity, availability of the Lewis acidic site and π-πinteraction influenced the EDS efficiency of ILs. Copyright © 2019 American Chemical Society.

Energy and Fuels

Effect of Nitro Groups on Desulfurization Efficiency of Benzyl-Substituted Imidiazolium-Based Ionic Liquids: Experimental and Computational Approach

The solvation behavior of ionic liquids containing a common, 1,1,3,3-tetramethylguanidinium cation and different anions, phenylacetate and cinnamate, in water is examined through apparent molar properties. These ionic liquids were chosen because of their versatile applications as environment-friendly solvent, catalyst, and for dissolution and stability of biomolecules. In order to understand the ion-ion and ion-solvent interactions and effect of anion in dilute aqueous solutions of studied ionic liquids, the experimental measurements of density and speed of sound have been carried out as a function of molality (0.01 to 0.2 mol·kg− 1) and temperature from 293.15 to 318.15 K. Experimental data have been used to calculate the apparent molar and other derived thermodynamic properties. Further, Redlich-Meyer equation has been employed to obtain the apparent molar volume and isentropic compressibility at infinite dilution and the empirical parameters which are crucial in understating the hydrophilic and hydrophobic nature of studied ionic liquids. © 2017 Elsevier B.V.

Understanding the solvation behavior of tetramethylguanidinium based ionic liquids in dilute aqueous solutions through apparent molar properties

In this work, we investigated the influence of two different anions on the various thermophysical properties of N,N-diethanolammonium based protic ionic liquids (PILs). For this purpose, two N,N-diethanolammonium based PILs have been synthesized by using trifluoroacetate and lactate as counter anions and characterized through spectral techniques. The thermophysical properties such as density and speed of sound were measured as function of temperature from (303.15 to 343.15) K at atmospheric pressure. The experimental density values used to calculate thermal expansion coefficient (α), isentropic compressibility (κs), molar volume (Vm) and standard entropy (So). The thermal stabilities of the PILs were investigated by thermogravimetric analysis (TGA), and phase transition measurement was done by using differential scanning calorimerty (DSC). Further, to understand the interionic strength of PILs, lattice potential energy (Upot) has been calculated. The experimental densities have been compared with the estimated densities obtained from Gardas and Coutinho model and obtained results are in good agreement. Further, the density values of studied protic ionic liquids have been compared with other protic ionic liquids. Finally, the impact of structure variants in terms of the carboxylate anions has been analyzed over the thermophysical properties of N,N-diethanolammonium based PILs. © 2017 Elsevier B.V.

Effect of anion on thermophysical properties of N,N-diethanolammonium based protic ionic liquids

Interpreting the physiochemical properties and structure-property correlations of ionic liquids (ILs) is a key to the enlargement of their optimized structures for specific applications. In this work, a series of ILs based on 1-alkyl-1,2,4-triazolium cation with trifluoromethanesulfonate anion were synthesized and the effect of cation and temperature on physiochemical properties such as density, viscosity, speed of sound, conductivity, and rheology was studied. Temperature dependence densities were correlated with the densities estimated by the Gardas and Coutinho model, whereas viscosity and molar conductivity have been found to satisfy the Vogel-Tammann-Fulcher (VTF) equation over the studied temperature range 293.15-343.15 K. Further, to explore the wide range of applications, ionicity has been tested by correlating the fluidity with molar conductivity and it was found that synthesized ILs can be referred to as "good ILs". Furthermore, the fluidity behavior describing the interactions between the cation and anion of ILs was investigated through their rheological properties, and the Newtonian behavior of ILs has been examined by varying the effect of shear rate on viscosity. Finally, the impact of structure variants in terms of the N-1 functionalized 1,2,4-triazole ring has been analyzed over the studied properties. © 2016 American Chemical Society.

Journal of Physical Chemistry B

Influence of Cation Size on the Ionicity, Fluidity, and Physiochemical Properties of 1,2,4-Triazolium Based Ionic Liquids

Understanding the volumetric behavior of ionic liquids with molecular solvents is essential for the development of industrial applications. In the present work, attempts have been made to explore and understand the effect of various structurally different protic ionic liquids upon the volumetric and acoustic behavior, when mixed with polar protic solvent (water) and polar aprotic solvent (N-methyl-2-pyrrolidone). Density and speed of sound for ten binary mixture containing five protic ionic liquids namely, propylammonium formate, propylammonium acetate, 3-hydroxypropylammonium formate, 3-hydroxypropylammonium acetate and 3-hydroxypropylammonium trifluoroacetate have been investigated over the whole range of composition at temperature from (293.15 to 333.15) K and at atmospheric pressure. The experimental density and speed of sound data have been used to calculate coefficient of thermal expansion, isentropic compressibility and excess molar volume of studied binary mixtures. In most of the studied binary systems the excess molar volumes were found to be negative and the experimental excess molar volumes have been correlated with Redlich-Kister equation. The protic and aprotic nature of molecular solvents along with its shape and size found to affect the studied volumetric properties. Moreover, the effect of anionic chain length, functionalization of cationic side with hydroxyl group and temperature upon studied properties has also been discussed. The results were analyzed on the basis of ion-dipole interaction, interstitial packing and hydrogen bonding between ionic liquids and molecular solvents. © 2016 Elsevier B.V. All rights reserved.

Structural and compositional effect on the acoustic and volumetric properties of ammonium based ionic liquids with water and N-methyl-2-pyrrolidone

In this work, two pyrrolidonium based ionic liquids namely N-methyl pyrrolidonium bisulfate ([NMP][HSO4]) and pyrrolidonium bisulfate ([PY][HSO4]) were synthesized and characterized by 1H NMR spectroscopy technique. The experimental density, speed of sound, viscosity and conductivity have been measured in the temperature range of (293.15–333.15) K and at 0.1 MPa pressure. From the experimental data, derived thermodynamic properties such as molecular volume, standard entropy, crystal energy, isobaric expansion coefficient, molecular free length and molar conductivity have been calculated. Empirical equations, Newton–Laplace equation, Vogel–Tammann–Fulcher equation and Walden equation were presented to understand the nature of the pure ionic liquids. Further, experimental measurements for density and speed of sound of binary mixtures of [PY][HSO4] with water and/or DMSO were studied as a function of IL concentration at various temperatures and apparent molar properties were calculated using Redlich-Mayer equation. Finally, experimental and derived thermodynamic properties were explored to understand the intermolecular interactions of studied systems. © 2016 Elsevier B.V.

Synthesis and thermophysical properties of pyrrolidonium based ionic liquids and their binary mixtures with water and DMSO at T = (293.15 to 333.15) K

N,N-dimethylethanolammonium (DMEA) based ionic liquids with carboxylate anions are very important in organic synthesis, gas absorption, biological and pharmaceutical applications. The fundamental physiochemical properties will give a platform to better understanding of their nature for scientific community. Here in this work, five DMEA based protic ionic liquids (PILs) with carboxylates were synthesized and their physicochemical properties such as density (ρ) and speed of sound (u) were measured as a function of temperature from (293.15-343.15) K at 0.1 MPa pressure. Several derived thermophysical properties such as molecular volume (Vm), standard entropy (S°), isothermal expansion coefficient (α) and isentropic compressibility (βs) have been calculated using experimental data. The effects of carboxylate anion chain length and temperature on physicochemical properties have been discussed. The crystal potential energy (UPOT) of ionic liquid compared with MX type of inorganic salt and discussed for ion interaction in PILs. © 2016 Elsevier B.V.

Fluid Phase Equilibria

Effect of anion chain length on physicochemical properties of N,N-dimethylethanolammonium based protic ionic liquids

Apparent molar volumes and apparent molar isentropic compressibilities of newly synthesized ammonium-based protic ionic liquid (PIL), namely diethylethanolammonium propionate, at T = (293.15 to 328.15) K and at atmospheric pressure were obtained from experimentally measured density and speed of sound data. Redlich-Mayer type of equation was used to calculate infinite dilution apparent molar volumes, V2 ∞, infinite dilution apparent molar isentropic compressibilities, Ks,2 ∞, and corresponding empirical parameters (Sv, Bv, Sk, and Bk). Positive magnitude of limiting volumetric slope Sv versus m1/2 for protic ionic liquid (PIL) + water binary solutions, suggests that PIL-water interactions are weak. Further, the temperature dependence of V2 ∞ values has also been evaluated. © 2015, Springer-Verlag Berlin Heidelberg.

Journal	Data powered by TypesetJournal of Molecular Liquids
Publisher	Data powered by TypesetElsevier B.V.
ISSN	01677322
Open Access	No