The experimental density, ρ, speed of sound, u and viscosity, η values as a function of ionic liquid concentration, m for binary mixtures (benzyldimethylammonium propionate/benzyldimethylammonium hexanoate + N,N-dimethylformamide) were measured at T = 293.15 to 328.15 K and at atmospheric pressure. Apparent molar volumes, Vφ, and apparent molar isentropic compressibilities, Ks,φ, have been determined from the experimental densities and speed of sound and fitted to a Redlich-Mayer equation for the calculation of limiting parameters (Vφ∞and Kφ∞). The calculated Vφ∞and Kφ∞values indicate that ionic liquid-molecular solvent interactions are stronger for benzyldimethylammonium hexanoate (BDMAH) in DMF than the benzyldimethylammonium propionate (BDMAP) in DMF mixtures. The limiting apparent molar expansibilities, α at each temperature for both ionic liquids in DMF have positive values. 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. © 2014 Elsevier B.V.

Ramesh L. Gardas

Department Of Chemistry

Dasthaiah Keshapolla

Ionic liquids

Viscosity

JONES-DOLE EQUATION

N ,N-Dimethylformamide

REDLICH-MAYER EQUATION

Density (specific gravity)

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

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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

In the present work, density, ρ and speed of sound, u measurements have been performed, for binary mixtures of two synthesized Brønsted-acidic ionic liquids namely N,N,N-triethyl-4-sulfobutaneammonium hydrogensulfate, [N222(C4SO3H)][HSO4] and N,N,N-triethyl-4-sulfobutaneammonium trifluoromethanesulfonate, [N222(C4SO3H)][CF3SO3] with water and DMSO as solvents. Experimental measurements have been carried out at variable concentrations of ILs in the temperature range of (293.15 to 328.15) K with the constant interval of 5 K and at atmospheric pressure. Using experimentally measured density and speed of sound data, apparent molar volume, Vϕ and apparent molar isentropic compressibility, Ks, ϕ and limiting apparent molar expansion, Eϕ ∞ have additionally been derived for the studied binary solutions. Apparent molar property data were fitted to the Redlich-Mayer type equation from which corresponding derived properties i.e. apparent molar volume and apparent molar isentropic compressibility at infinite dilutions, Vϕ ∞ and κs, ϕ ∞ were attained. Magnitude of these derived properties and corresponding empirical parameters were evaluated in the scope of understanding the nature of interactions prevailing among ions of ILs as well as ions and solvents. © 2018 Elsevier B.V.

Understanding the solvation behavior of SO3H functionalized Brønsted acidic ionic liquids in water and DMSO: Volumetric and acoustic approach

To understand the molecular interactions among the components of aqueous solutions with cholinium based aprotic ionic liquids (AILs), their partial molar properties have been studied. Four cholinium based AILs-namely, cholinium propanoate ([Chl][Pro]), cholinium butanoate ([Chl][But]), cholinium pentanoate ([Chl][Pen]) and cholinium hexanoate ([Chl][Hex]) were synthesized and characterized. Thermodynamic properties of these AILs in water at various temperature (293.15 to 333.15) K and at atmospheric pressure were determined from density and speed of sound measurements. Derived thermodynamic properties and related empirical parameters at infinite dilution were also determined using the Redlich-Mayer type of equation. The studied AILs are observed to interact strongly with water, although the ion-solvent interactions decrease with increase in temperature as well as with increase in concentration. © 2018 Elsevier B.V.

Molecular interactions of choline based ionic liquids with water at different temperatures: An experimental study

The precise and accurate thermophysical properties determination of ionic liquid (IL)-solvent binary system is needed for understanding the molecular interactions occurring between these components. The nature of ion-ion and ion-solvent interactions can be studied either experimentally on the basis of apparent and partial molar properties and corresponding infinite dilution properties or by computational studies. In this regard, we have measured the thermodynamic properties of binary aqueous solutions containing newly synthesized N-methylpyrrolidone based protic ionic liquids (PILs) in the temperature range (288.15–328.15) K and at ambient pressure. Experimentally measured density and speed of sound data have been used to calculate the infinite dilution partial molar properties and the corresponding empirical parameters through the Redlich-Mayer type of equation. It is observed that the studied PILs interacts strongly with water, however the ion-solvent interactions decreases with increase in anionic chain length and increase in temperature. Observed intra-ionic and inter-ionic interactions in studied aqueous ionic liquid mixtures were also supported by Density Functional Theory (DFT) calculations. © 2017 Elsevier B.V.

Fluid Phase Equilibria

Understanding ion-ion and ion-solvent interactions in aqueous solutions of NMP based protic ionic liquids through partial molar properties and DFT calculations

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.

Effect of temperature on apparent molar properties of DBU based protic ionic liquid in aqueous and ethanolic solutions

Lactam based ionic liquids were synthesized by an atom economization process between a lactam such as caprolactam or butyrolactam with a Brønsted acid such as formic acid, acetic acid or hexanoic acid. The density, speed of sound and viscosity were measured at atmospheric pressure and as a function of temperature from T = (293.15 to 333.15) K. The experimental density and viscosity values were fitted with linear and Vogel-Tamman-Fulcher (VTF) equations, respectively and found to be fitting well within the experimental error. Thermodynamically important derived properties such as the coefficient of thermal expansion (α) and isentropic compressibility (βs) were calculated from the experimental density and speed of sound values. Lattice potential energy (UPOT) has been calculated to understand the strength of ionic interaction between the ions and the standard entropy (So) has been estimated to assess the disorder within the fluids. The remarkably low values of viscosity of ionic liquids studied are discussed on the basis of activation energy estimated from the Arrhenius equation. Furthermore, the effect of alkyl chain length on the anion, geometry of the cation and temperature has been analysed for the properties studied. © 2014 Elsevier Ltd. All rights reserved.

Journal of Chemical Thermodynamics

Physicochemical properties of low viscous lactam based ionic liquids

The densities, ρ and speeds of sound, u of d(+)-glucose and d(-)-ribose in water and in (0.10, 0.20, 0.30, and 0.40) mol·kg-1 aqueous protic ionic liquid (3-hydroxy propylammonium formate) solutions were measured at temperatures, T = (298.15 to 318.15) K. Infinite dilution standard partial molar volume, V2 and standard partial molar isentropic compressibility, Ks,2 have been calculated, which were used to evaluate the standard transfer volumes, ΔtV2 and ΔtKs,2. The ΔtV2 and ΔtKs,2 values for monosaccharides decrease in the order: d(+)-glucose &gt; d(-)-ribose. The transfer parameters are positive and increase with molalities of ionic liquid (IL) and with temperature. Further, the expansion coefficients, (∂V2/∂T)P, its derivative ( ∂2V2/∂T2)P, pair (VAB and KAB) and triplet (VABB and KABB) volumetric interaction coefficients and hydration numbers, Nw have also been calculated and used to discuss the solvation behaviour of monosaccharides. The variation in the taste quality of monosaccharides in the presence of IL has also been studied from apparent massic volume, v and apparent massic isentropic compressibility, Km parameters. © 2013 Elsevier Ltd. All rights reserved.

Solvation behaviour and partial molar properties of monosaccharides in aqueous protic ionic liquid solutions

In this work, five protic ionic liquids having propylammonium, 3-hydroxy propylammonium as cations and formate, acetate, trifluoroacetate as anions have been synthesized. Thermophysical properties such as density (ρ), viscosity (η) and sound velocity (u) have been measured at various temperatures ranging from (293.15 to 343.15) K at atmospheric pressure. The experimental density and viscosity were fitted with second order polynomial and Vogel-Tamman-Fulcher (VTF) equations, respectively. Also experimental densities were correlated with the estimated density proposed by Gardas and Coutinho model. The coefficient of thermal expansion (α) and isentropic compressibility (βs) values have been calculated from the experimental density and sound velocity data using empirical correlations. Lattice potential energy (UPOT) has been calculated to understand the strength of ionic interaction between the ions. Thermal decomposition temperature (Td) and glass transition temperature (Tg) along with crystallization and melting point were investigated using TGA and DSC analysis, respectively. The effect of alkyl chain length and electronegative fluorine atoms on anionic fragment as well as hydroxyl substituent on cationic side chain in the protic ionic liquids has been discussed for studied properties. The effect of ΔpKa over the studied properties has also been analyzed. © 2014 Elsevier Ltd. All rights reserved.

Thermophysical properties of ammonium and hydroxylammonium protic ionic liquids

A series of alkyltrioctylphosphonium chloride ionic liquids, prepared from trioctylphosphine, and the respective 1-chloroalkane (CnH 2n+1Cl), where n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 or 14, is presented. The cynosure of this work is the manner in which the variable chain length impacts the physical properties, such as melting points/glass transitions, thermal stability, density and viscosity. Experimental density and viscosity data were interpreted using QPSR correlations and group contribution methods. We present the first example of an empirical alternation effect for ionic liquids. © 2011 The Royal Society of Chemistry.

Dalton Transactions

Alkyltrioctylphosphonium chloride ionic liquids: Synthesis and physicochemical properties

Journal of Chemical & Engineering Data

Apparent Molar Volumes and Expansivities of Ionic Liquids Based on N-Alkyl-N-methylmorpholinium Cations in Acetonitrile

Volumetric, acoustic and transport properties of binary mixtures of benzyldimethylammonium based ionic liquids with N,N-dimethylformamide at temperature from 293.15 to 328.15 K

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