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.

Ramesh L. Gardas

Department Of Chemistry

Gyanendra Sharma

Atmospheric pressure

compressibility

Ionic liquids

Temperature distribution

Volatile fatty acids

Volume measurement

APPARENT MOLAR ISENTROPIC COMPRESSIBILITIES

APPARENT MOLAR PROPERTIES

Apparent molar volume

DIETHYETHANOLAMMONIUM PROPIONATE

EMPIRICAL PARAMETERS

PROTIC IONIC LIQUIDS

temperature dependence

WATER INTERACTIONS

Liquids

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IIT Madras

Ionics

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.

Journal of Molecular Liquids

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 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

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

In this work, five protic ionic liquids (PILs) have been synthesized through atom economic neutralization reaction between N-butyl hydroxyethyl amine and brønsted acid RCOOH, where R is H, CH3, C2H5, C3H7, and C4H9. Thermophysical properties such as density, speed of sound and viscosity were measured in the temperature range from 293.15 to 343.15 K at 0.1 MPa pressure. The density data have been fitted to second order polynomial equation as well as correlated with group contribution method developed by Gardas and Coutinho. From the density correlation, molecular volume data for cation and anion constituents of studied ionic liquids have been proposed. Further, the coefficient of thermal expansion, isentropic compressibility, standard entropy, intermolecular free length and potential energy have been calculated by using experimental density and speed of sound data. Viscosity data were correlated with the Vogle-Tamman-Fulcher equation. The relationship between the standard entropy of ionic liquid and the carbon atom number in alkyl chain of the carboxylate anions studied at 298.15 K. Furthermore, the effect of alkyl chain length and temperature has been analyzed for the studied properties. © 2016 Elsevier B.V.

Fluid Phase Equilibria

Measurement and correlation for the thermophysical properties of hydroxyethyl ammonium based protic ionic liquids: Effect of temperature and alkyl chain length on anion

The volumetric properties and taste behaviour of sucrose in aqueous solutions of a protic ionic liquid (3-hydroxypropylammonium acetate) have been studied at temperatures, T = (293.15-318.15) K and at atmospheric pressure. Apparent molar volumes, V2,φ, apparent specific volumes, ASV, apparent molar isentropic compressibilities, Ks,2,φ, and apparent specific isentropic compressibilities, ASIC, were calculated from measured density, ρ and speed of sound, u data. Partial molar volumes, V 2°, and partial molar isentropic compressibilities, Ks,2° at infinite dilution, transfer parameters (ΔtV2° and ΔtK s,2°), expansion coefficients, [(∂V 2°/∂T)P and (∂2V 2°/∂T2)P], interaction coefficients, (YAB and YABB) and hydration numbers, N w, were also evaluated and discussed in terms of solute-cosolute interactions. Further, the effect of protic ionic liquid on the taste behaviour of sucrose has been discussed from ASV and ASIC parameters, as these parameters, which are sensitive to solvation behaviour of solute, are divided into four basic taste qualities occupying certain ranges. © 2014 Elsevier Ltd. All rights reserved.

Food Chemistry

Effect of protic ionic liquid on the volumetric properties and taste behaviour of sucrose

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.

Journal of Chemical Thermodynamics

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.

Journal	Ionics
Publisher	Institute for Ionics
ISSN	09477047
Open Access	No