Standard Partial Molar Volumes Research Articles

Solvation properties of 1-alkyl-3-methylimidazolium thiocyanate ionic liquids in the presence of lithium halide salts in N-methyl-2-pyrrolidone

Recently, ionic liquids in design and optimization of the membrane technology were applied. Thiocyanate based ionic liquids as green and fluorine-free solvents were used effectively in the preparation of membranes that were used in separation and purification. In this work, 1-alkyl-3-methylimidazolium thiocyanate, [RMIM][SCN] (R = butyl, hexyl, and octyl), were synthesized and some of the thermophysical properties of (IL + LiX (X = Cl, Br) + N-methyl-2-pyrrolidone) ternary solutions including density, speed of sound and viscosity data have been determined at T = 298.15 K. Also, the standard partial molar volumes Vφ0, partial molar isentropic compressibility κφ0 and viscosity B-coefficients have been calculated. The scaled particle theory (SPT) was used to determining of different contributions of the Vφ0. The obtained quantities were used to interpret the influence of lithium halide salts on the solute-solvent interactions in the studied IL solutions.

Correction: What is the fundamental ion-specific series for anions and cations? Ion specificity in standard partial molar volumes of electrolytes and electrostriction in water and non-aqueous solvents.

Correction for ‘What is the fundamental ion-specific series for anions and cations? Ion specificity in standard partial molar volumes of electrolytes and electrostriction in water and non-aqueous solvents’ by Virginia Mazzini et al., Chem. Sci., 2017, 8, 7052–7065.

Interaction Between an Active Pharmaceutical Ingredient Ionic Liquid Benzalkonium Salicylate and Small Biomolecules in Aqueous Solution: UV Absorption, Conductivity, and Volumetric Study

UV absorption spectroscopy, electrical conductivity and density experiments have been used to investigate the interactions of some small biomolecules (amino acids/dipeptides) with an active pharmaceutical ingredient in ionic liquid form (API-IL), benzalkonium salicylate (BaSal), in aqueous solution. A number of useful parameters, such as critical micellar concentration (cmc), aggregation number (Nagg) and limiting molar conductivity (Λ0) of BaSal, standard partial molar volumes (\(V_{2,\phi }^{ \circ }\)), corresponding volumes of transfer from water to aqueous BaSal solutions (ΔtrVo), standard partial molar expansibilities (\(E_{\phi }^{ \circ }\)), hydration number (nH) of small biomolecules, as well as the binding constants (Kb) for small biomolecule–BaSal complexes have been evaluated. The dependence of the properties on concentration, temperature and alkyl chain length of amino acids/dipeptides is examined. The results are used to identify the solute–solvent physicochemical interactions occurring in the studied systems.

Thermophysical properties of ionic liquid, 1‑ethyl-3-methylimidazolium ethyl sulfate in organic solvents at dilute region

This paper reports the density, speed of sound, viscosity and refractive index data of the ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate in some polar organic solvents, 1-propanol, ethanol, methanol and acetonitrile in dilute region of the ionic liquid concentration at temperature ranges T = (288.15 to 318.15) K and at atmospheric pressure. On the basis of density and speed of sound data, the apparent molar volume Vφ and apparent molar isentropic compressibility κφ were calculated. From these quantities and with help of Redlich-Mayer equation, the standard partial molar volumes and partial molar isentropic compressibility were obtained. The obtained parameters show that the strength of solute-solvent interactions. The Jones-Dole equation was used for correlating of viscosity data. In addition, the solvation numbers was estimated using the obtained values for the viscosity B-coefficient and the standard partial molar volume for the systems studied at various temperatures. Molar refractions were obtained by using the Lorentz-loran's equation which used to interpret the polarizability of the solutions.

Standard Partial Molar Heat Capacities and Volumes of Barium and Cadmium Ions in Dimethylformamide at 298.15 K

The heat capacity and bulk properties of barium and cadmium iodide solutions in dimethylformamide (DMF) at 298.15 K are measured via calorimetry and densimetry. Standard partial molar heat capacities $$\bar {C}_{{p,2}}^{^\circ }$$ and volumes $$\bar {V}_{2}^{^\circ }$$ ВаI2 and CdI2 in DMF are calculated. The standard values of heat capacity $$\bar {C}_{{p,i}}^{^\circ }$$ and volume $$\bar {V}_{i}^{^\circ }$$ of barium and cadmium in DMF at 298.15 K were determined.

Acoustic and thermodynamic study of D-Panthenol in aqueous solutions of glycol at different temperatures

Abstract The interaction of EG, DEG and TEG with biologically active D-Panthenol, as the function of temperature has been investigated by the combination of acoustic and volumetric methods. Speeds of sound and densities of EG, DEG and TEG in (0.05, 0.10 and 0.15) mol·kg−1 in aqueous solutions of D-Panthenol have been measured at T = (293.15, 298.15, 303.15 and 308.15) K. From the density data, the apparent molar volume ( V ϕ 0 ) and standard partial molar volume of transfer Δ V ϕ 0 for EG, DEG and TEG in aqueous D-Panthenol solutions have been determined. From the speed of sound data, the partial molar isentropic compression K ϕ , s and the partial molar isentropic compression of transfer Δ K ϕ , s 0 , have been determined. The pair and triplet interaction coefficient have also been estimated.

Standard Partial Molar Heat Capacities and Volumes of Barium and Cadmium Ions in Dimethylsulfoxide at 298.15 K

The heat capacities and volumes of dimethylsulfoxide (DMSO) solutions of barium and cadmium iodides at 298.15 K were measured by calorimetry and densimetry. The standard partial molar heat capacities $$\bar {C}_{{p,2}}^{^\circ }$$ and volumes $$\bar {V}_{2}^{^\circ }$$ of BaI2 and CdI2 in DMSO were calculated. The standard heat capacities $$\bar {C}_{{p,i}}^{^\circ }$$ and volumes $$\bar {V}_{i}^{^\circ }$$ of barium and cadmium ions in DMSO at 298.15 K were determined.

Structural changes of water caused by non-electrolytes: Volumetric and compressibility approach for urea-like analogues

Hydration of thiourea (TU), hydroxyurea (HU, hydroxycarbamide), acetone (AC, 2-propanone) and dimethyl sulfoxide (DMSO) has been investigated with the help of the volumetric and compression measurement. The apparent molar volumes and the apparent molar isentropic (adiabatic) compression have been calculated from the density and speed of sound data at temperatures ranging from 288.15 to 308.15 K at atmospheric pressure (0.1 MPa). From these data the standard partial molar volumes and the standard partial molar isentropic compressions have been calculated.The properties of the hydration spheres formed around investigated solutes have been characterised based on four parameters: (i) empirical slope for the dependency of the apparent molar volume on the concentration, (ii) difference between standard partial molar volume and van der Waals volume, (iii) standard partial molar compression, (iv) temperature dependency of the standard partial molar compression. The obtained results have been discussed and compared with the solvation properties of the N-alkyl derivatives of urea.

Volumetric and acoustic behaviour of myo-inositol in aqueous Natural Deep Eutectic Solvent solutions

A study of the interactions in aqueous systems containing a sweetener, myo-inositol, and a NAtural Deep Eutectic Solvent, reline or glyceline, is presented. Both NADESs include the same acceptor group, choline chloride, and different donor groups, urea and glycerol. For this purpose, the density and speed of sound were measured for dilute mixtures, and several related properties were calculated: the standard partial molar volume, the standard partial molar isentropic compression, the standard transfer properties, Hepler's constant, and the compressibility hydration number. The results were evaluated as a function of the temperature and composition, and they show the dominance of the ionic-hydrophilic and hydrophilic-hydrophilic interactions. Moreover, the glyceline disturbs the aqueous mixtures more than the reline.

Studies on the interactions of some small biomolecules with antibacterial drug benzethonium chloride and its active pharmaceutical ingredient ionic liquid (API-IL) benzethonium L-proline at varying temperatures

From the conductivity, density and spectroscopy measurements, the interactions of benzethonium chloride ([BTC]) and its active pharmaceutical ingredient in ionic liquid format benzethonium L-proline ([BT][PRO]) with some amino acids and glycyl dipeptides have been examined. A number of useful parameters, such as standard partial molar volume (V2, ϕo), partial molar transfer volume (ΔtVo), standard partial molar expansibility (Eϕo) of these small biomolecules, critical micelle concentration (cmc), aggregation number (Nagg), thermodynamic micellization parameters of [BTC]/[BT][PRO], as well as binding constant for small biomolecule-drug complex have been evaluated. Group contributions of charged end group (NH3+, COO−), CH2 and (CH2CONH) groups of amino acids/dipeptides to V2, ϕo values have also been perceived. These parameters are helpful to study the structure making capacity of small biomolecules, solvation behavior of [BTC]/[BT][PRO] and various interactions present in the studied ternary solution. The interaction difference of [BTC] and [BT][PRO] with small biomolecules was studied.

Interactions in aqueous solutions of imidazolium chloride ionic liquids [Cnmim][Cl] (n = 0, 1, 2, 4, 6, 8) from volumetric properties, viscosity B-coefficients and molecular dynamics simulations

In this work a systematic study of aqueous diluted solutions (~0.005 < m/mol·kg−1 < ~0.1) of six imidazolium based ionic liquids (IL) [Cnmim][Cl] with different alkyl chain lengths (n = 0, 1, 2, 4, 6, 8) was carried out. Densities and viscosities were measured as a function of IL concentration in the temperature range between 278.15 K and 313.15 K in steps of 5 K. From experimental data, apparent molar volumes, standard partial molar volumes, and viscosity B-coefficients of ILs were derived. The effect of the alkyl chain length on the estimated properties was discussed in terms of ion-ion and ion-solvent interactions. It turned out that the studied cations with longer alkyl side chain (n = 4, 6, 8) can be regarded as structure makers; cations with shortest side chain (n = 0, 1) as structure breakers, whereas [C2mim]+ can be considered as a border line ion. In order to obtain more information about interactions and influence of studied ILs on water structure, computational simulations were performed. For this purpose, DFT calculations using B3LYP-D3 functional and molecular dynamic simulations with OPLS 2005 force field, were applied. Obtained results show that the increase in length of alkyl substituent in imidazolium ring leads to weakening of interactions with water molecules.

Physicochemical properties of L-carnitine in aqueous solution and its interaction with trimethylamine N-oxide, sodium chloride and dextrose: Volumetric and calorimetric insights

Abstract L -carnitine plays physiologically important roles specifically to decrease triglycerides, very low density lipoprotein (VLDL) and cholesterol. Considering these facts, it is believed to be helpful in the reduction of cardiovascular diseases and diabetes. Physicochemical properties of L -carnitine in aqueous or mixed aqueous solutions are scarcely available in literature. Such properties will be useful in understanding the interactions of L -carnitine with other cellular components like trimethylamine-N-oxide (TMAO), dextrose ( D -glucose) and NaCl. The values of densities (ρ) and speeds of sound (u) of L -carnitine were measured over the molality range of m = 0.05 mol·kg−1 to m = 0.3 mol·kg−1 at temperature T = 293.15 K to T = 313.15 K in water and in aqueous solutions of TMAO, dextrose, and NaCl. Using these data, values of apparent molar volume (V2,m,φ) and apparent molar adiabatic compressibility (Ks,2,m,φ) have been determined. The results obtained from these measurements have been used to derive the standard partial molar volume ( V 2 , m o ), standard partial molar adiabatic compressibility ( K s , 2 , m o ), standard partial molar volume of transfer ( Δ tr V 2 , m o ) and standard partial molar isentropic compressibilities of transfer ( Δ tr K S , 2 , m o ) from water to aqueous solutions of TMAO, dextrose, and NaCl. Through Isothermal Titration Calorimetry (ITC), the enthalpies of dilution ( Δ dil H m ) of L -carnitine in water (over a temperature range of T = 293.15 K to T = 313.15 K) and in aqueous solutions of TMAO, dextrose, and NaCl have been determined. The values of standard molar enthalpy of dilution ( Δ dil H m o ) and their transfer values ( Δ tr Δ dil H m o ) have been derived from these measurements. The results have been discussed in terms of possible intermolecular interactions. The data suggest that there is overall balancing of hydrophobic and hydrophilic interactions in system containing L -carnitine and TMAO in aqueous solution, but hydrophobic effect dominates when the co-solute is NaCl or dextrose.

Study on thermophysical properties in the ternary mixture of N-methylglycine solute with (d-glucose + water) binary solvent at temperatures of 298.15, 308.15, and 318.15 K

Density, speed of sound and refractive index data were measured to eight molal concentrations of N-Methylglycine in aqueous d-Glucose for mixed ternary solutions. The molality of N-methylglycine solute is between 0.3140 and 1.2005 mol·kg−1 in 0.2052, 0.4201, 0.6455, and 0.8824 mol·kg−1 aqueous d-glucose solvent at temperatures of 298.15, 308.15, and 318.15 K and at atmospheric pressure. The relation between experimental data of refractive index and density has been good correlated with several empirical and semi-empirical equations like Lorentz–Lorenz, Dale–Gladstone, Eykman, Oster, Arago–Biot, Newton and Modified–Eykman. As well, the derived thermophysical properties as the apparent molar volumes, the standard partial molar volume, standard partial molar volumes of transfer from water to (d-glucose + H2O) solutions, isentropic compressibility coefficient, the estimation of the isentropic compressibility at infinite dilution, and solvation number were calculated from measured values of densities and speeds of sound. Finally, the molar refractivity in ternary mixture was computed using Lorentz-Lorenz equation. The influence of the amino acid and carbohydrate concentration on the thermophysical properties has been evidenced. The obtained values were interpreted in terms of solute-cosolute and solute-solvent interactions present in the studied aqueous mixtures.

Studies on the interactions behaviour of polyhydroxy solutes d (+)-glucose and d (−)-fructose in aqueous triammonium citrate solutions over temperature range T = (288.15–318.15) K

Abstract The interactions of polyhydroxy solutes d (+)-glucose and d (−)-fructose with aqueous solutions of triammonium citrate (TAC) as a function of temperature have been enquired upon by combination of volumetric and ultrasonic studies. Densities and speed of sound of d (+)-glucose and d (−)-fructose in (0.2, 0.4 and 0.6) mol·kg−1 aqueous solutions of triammonium citrate (TAC) are measured at T = (288.15, 298.15, 308.15 and 318.15) K and experimental pressure p = 0.1 MPa. The apparent molar volume, V ϕ , the partial molar volume V ϕ o , and standard partial molar volumes of transfer, Δ V ϕ o for d (+)-glucose and d (−)-fructose from water to aqueous solutions of triammonium citrate (TAC) have been calculated from density data. Apparent molar isentropic compression, K ϕ , s , partial molar isentropic compression K ϕ , s o and partial molar isentropic compression of transfer, Δ K ϕ , s o have been calculated from ultrasonic speed data. The expansibility parameter (∂Vϕ0/∂T)p and its derivative (∂2Vϕ0/∂2T)p along with pair (VAB, KAB) and triplet (VABB, KABB) interaction coefficients have also been calculated. The results have been interpreted in terms of solute–solute and solute–solvent interactions in these systems.

Modulation of hydration characteristics of carbohydrates in aqueous medium of γ-amino butyric acid via volumetric, rheological and time-domain longitudinal NMR relaxation studies

Carbohydrates such as saccharides and their derivatives are engaged in various biological processes such as in transportation and transmission of genetic material, enzymatic processes, and regulation of metabolism. γ-Amino butyric acid (γ-ABA) is a non-protein amino acid and acts as an inhibitory neurotransmitter in the mammalian cerebral cortex. Volumetric, rheological and spectroscopic investigations are helpful to elucidate the molecular interactions occurring between carbohydrates and γ-ABA in aqueous solution. Therefore, the standard state partial molar volumes, V2° and Jones-Dole viscosity B-coefficients of monosaccharides and their derivatives, polyols and disaccharides were determined in molality, mB range (0.05–0.50) mol·kg−1 aqueous solutions of γ-ABA from the precise density and viscosity measurements at temperature range T=(288.15–318.15) K. These data were used to obtain the corresponding volumes of transfer, ΔtrV2° and change in viscosity B-coefficient, ΔB for carbohydrates from water to aqueous solutions of γ-ABA. The taste quality of studied solutes (carbohydrates) has been appraised in the presence of γ-ABA from apparent massic volumes. The volumetric and viscometric interaction coefficients were calculated from the McMillan-Mayer theory of solutions. The expansion coefficients (∂V2°/∂T)P, second-order derivatives (∂2V2°/∂T2)P and dB/dT coefficients were also determined to study the influence of temperature. These quantities have been explained in terms of various interactions occurring in the ternary system on the basis of co-sphere overlap model suggested by Gurney (1953). Proton (1H) NMR relaxation rates (R1) were also obtained for carbohydrates in different γ-ABA solutions made in 9:1 (w/w) (H2O+D2O) solvent, at T=300K. The results have been compared with our previously reported (Banipal et al., 2015, 2016) studies carried out in L-glycine. The stereochemical effects of studied solutes on hydration controlled by their domineering conformations have also been discussed.

Effect of Some Imidazolium-Based Ionic Liquids with Different Anions on the Thermodynamic Properties of Acetaminophen in Aqueous Media at T = 293.15 to 308.15 K

In this work, the effect of two imidazolium-based ionic liquids with different anions, 1-butyl-3-methylimidazolium bromide, [BMIm]Br, and 1-butyl-3-methylimidazolium chloride, [BMIM]Cl, on thermodynamic properties of acetaminophen was investigated. For this purpose, measurement of density ρ speed of sound u and specific electrical conductivity κ for acetaminophen in aqueous solutions of ionic liquid was made at T = 293.15 to 308.15 K and at atmospheric pressure. The standard partial molar volumes Vϕ0, partial molar isentropic compressibility Kϕ0, hydration number nH, and Hepler’s constants (∂2Vϕ0/∂T2)P have been calculated from the density and speed of sound data. The limiting molar conductivities Λ0 and ion association constants KA for the ionic liquids in aqueous solutions of acetaminophen have been estimated using the low concentration chemical model (lcCM). The results confirm presence of a strong attractive interaction between acetaminophen molecules and the ionic liquids which that becomes stronger ...

Study of intermolecular interactions in the ternary (1-Ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO4] / 1-Butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] + D(−)fructose + water) systems using the volumetric properties at different temperatures and ambient pressure

In continuation of our previous works, using the density measurement, we studied some important volumetric properties such as: apparent molar volumes, standard partial molar volumes, limiting apparent molar volumes of transfer, and limiting apparent molar expansibility for the ternary (ionic liquids 1-Ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO4]/1-Butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4]+D(−)fructose+water) at T=(293.15 to 313.15) K. By using the standard partial molar volumes and limiting apparent molar volumes of transfer, the nature of possible interactions in studied solutions are considered. Results demonstrated that for both studied ionic liquids, the Vφ values are increased with rising concentration of ionic liquids and temperature. Also by applying the first derivative of limiting apparent molar expansibility with respect to temperature, the structure maker ability of studied ionic liquids in aqueous D(−)fructose solutions are confirmed.

Volumetric Properties, Viscosity, and Refractive Indices of Different Naringenin Solutions at Several Temperatures

Thermophysical properties including densities and viscosities of naringenin in aqueous solutions of ethanol/1-propanol with alcohol concentrations of (24.00 to 40.00) mol·kg–1 have been measured as a function of concentration of naringenin at temperatures from (293.15 to 323.15) K and atmospheric pressure. Also, refractive indices for studied systems have been determined at 298.15 K. The measured data were used to calculate the apparent molar volume (Vϕ), standard partial molar volume (Vϕ0), partial molar volume (V), viscosity B-coefficients, and molar refractions (Rm). The viscosity and refractive index data have been analyzed by Jones–Dole and Lorentz–Lorenz equations, respectively. The trends of variation of experimental and calculated parameters have been discussed according to the interactions between solvents and solute. The obtained results imply that naringenin acts as a structure maker in the studied system.

Densities and Molar Volumes of Aqueous Solutions of Li2SO4 at Temperatures from 343 to 573 K

Densities of aqueous solutions of lithium sulfate (Li2SO4) at solute molalities ranging from 0.05 to 2.7 mol·kg–1 have been measured by vibrating-tube densimetry over the temperature range 373.15 ≤ T/K ≤ 573.15 at pressures close to the saturated vapor pressure of pure water. The apparent molar volumes (Vϕ) of Li2SO4(aq) calculated from these data together with previously published data at 323.15 and 343.15 K were fitted using a modified Redlich–Rosenfeld–Meyer equation, which in turn was used to extrapolate the experimental data to infinite dilution to obtain the standard partial molar volumes. A comparison of the present and literature data revealed the latter are inaccurate at low concentrations and are increasingly unreliable at higher temperatures. The combination of the present results with selected literature data produced a reliable equation of state for Li2SO4(aq) covering the temperature and pressure ranges 323.15 ≤ T/K ≤ 573.15 and 0.1 ≤ p/MPa ≤ 40. The volumetric behavior of Li2SO4(aq) was fou...

Volumetric, acoustic and spectroscopic studies (FT-IR) of trisodium (TSC) and tripotassium citrate (TPC) in aqueous solution of ionic liquid 1-butyl-3-methylimidazolium tetrafluoro borate [C4mim][BF4] at different temperatures

In this work, density ρ, and speed of sound u, for citrate salts trisodium citrate (TSC) and tripotassium citrate (TPC) have been measured in (0.005, 0.01, 0.03 and 0.05) mol·kg−1 aqueous solution of ionic liquid 1-butyl-3-methylimidazolium tetrafluoro borate ([C4mim][BF4]) at different temperatures T=(288.15, 293.15, 298.15, 303.15, 308.15) K at experimental pressure p=0.1MPa. Different parameters such as apparent molar volume (Vϕ), partial molar volume (Vϕ0), and standard partial molar volumes of transfer (ΔVϕ0) have been calculated by using the experimental density data. From experimental speed of sound data apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression (Kϕ,so), and partial molar isentropic compression of transfer (ΔKϕ,so) have been calculated. The pair and triplet interaction coefficients have been calculated from transfer parameters. Infrared spectral studies have also been carried out for the present mixtures. Work is mainly concerned with the study of the interactions present in the mixtures of trisodium citrate and tripotassium citrate in aqueous solutions of ionic liquid 1-butyl-3-methylimidazolium tetrafluoro borate [C4mim][BF4].