Volumetric studies of ion solvation in propylene carbonate + N,N-dimethylformamide electrolyte solutions

2003 ◽  
Vol 81 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Yang Zhao ◽  
Jianji Wang ◽  
Xiaopeng Xuan ◽  
Ruisen Lin
Keyword(s):  
Propylene Carbonate ◽  
Tetrabutylammonium Bromide ◽  
Partial Molar Volumes ◽  
Lewis Base ◽  
Ion Solvation ◽  
Scaled Particle Theory ◽  
Solvent Mixtures ◽  
Tetraethylammonium Bromide ◽  
Molar Volumes ◽  
Tetraalkylammonium Cations

Apparent molar volumes V2,ϕ and standard partial molar volumes V°2,ϕ for tetraethylammonium bromide (Et4NBr), tetrapropylammonium bromide (Pr4NBr), tetrabutylammonium bromide (Bu4NBr), and tetrahexylammonium bromide (Hex4NBr) have been determined at 298.15 K from precise density measurements in solvent mixtures of propylene carbonate (PC) with N,N-dimethylformamide (DMF). Combined with our previous data for LiClO4 and LiBr in the same solvents, ionic molar volumes of Li+, Et4N+, Pr4N+, Bu4N+, Hex4N+, and related anions have been deduced from the extrapolation method suggested by Conway and co-workers. It is shown that the molar volumes of these cations are quite independent of the nature of the solvent and the composition of the solvent mixtures, in contrast to those of ClO4– and Br– anions. This suggests that the Lewis-base-type solvents with similar molecular volumes have similar interactions with Li+. The constancy in partial molar volume for tetraalkylammonium ions provides helpful evidence for the lack of solvation of large tetraalkylammonium cations in organic solvents. These findings have been interpreted using scaled-particle theory. The results are discussed in terms of ion solvation, packing effects of solvent molecules in the solvation shell, and the electrostriction of solvents.Key words: ionic volumes, propylene carbonate, N,N-dimethylformamide, solvent mixtures, solvation, lithium batteries.

A partial-molar volume study of electrolytes in propylene carbonate-based lithium battery electrolyte solutions at 298.15 K

2002 ◽  
Vol 80 (7) ◽  
pp. 753-760 ◽  
Author(s):  
Jianji Wang ◽  
Yang Zhao ◽  
Kelei Zhuo ◽  
Ruisen Lin
Keyword(s):  
Molar Volume ◽  
Propylene Carbonate ◽  
Partial Molar Volume ◽  
Lithium Battery ◽  
Preferential Solvation ◽  
Partial Molar Volumes ◽  
Scaled Particle Theory ◽  
Solvent Mixtures ◽  
Particle Theory ◽  
Molar Volumes

Apparent molar volumes (V2, ϕ ) and standard partial-molar volumes (V20, ϕ ) of LiClO4 and LiBr at 298.15 K have been determined from precise density measurements in solvent mixtures of propylene carbonate (PC) with dimethylformamide (DMF), tetrahydrofuran (THF), acetonitrile (AN), and methyl formate (MF). The scaled particle theory is used to calculate the contributions of the cavity formation and the electrolyte-solvent interactions to the standard partial-molar volumes. It is shown that V20, ϕ is strongly dependent on the nature of the solvents, and the trends in V20, ϕ with composition of the solvent mixtures are determined by the interaction volumes of electrolytes with solvents. The results are discussed in terms of ionic preferential solvation, packing effect of solvents in the solvation shell, and electrostriction of solvents by ion.Key words: partial-molar volume, scaled particle theory, lithium salts, propylene carbonate, solvent mixtures, lithium battery electrolytes.

scholarly journals Density and Solvation Effects of Imidazolium Based Ionic Liquids in Propylene Carbonate

2018 ◽  
Keyword(s):  
Ionic Liquids ◽  
Propylene Carbonate ◽  
Partial Molar Volumes ◽  
Solvation Shell ◽  
Carbonyl Oxygen ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Intrinsic Volume ◽  
Negative Contribution ◽  
Molar Volumes

The results of densimetry investigation of the solutions of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), hexafluorophosphate (BMIMPF6) and bromide (BMIMBr) in propylene carbonate (PC) at 298.15, 318.15, 338.15 and 358.15 К are presented and discussed in terms of apparent partial molar volumes and solvation contribution. Density measurements were carried out using the vibrational tube densitometer Mettler Toledo DM 50 with accuracy ± 3∙10-5 g/cm3. The limiting partial molar volumes of investigated ionic liquids in PC were obtained from density experiment using Masson equation and divided into ionic contributions. Limiting partial molar volumes of BMIMBF4, BMIMPF6 and BMIMBr in PC slightly increase with the increase of temperature. The limiting partial molar volumes of BMIM+ cation obtained from three ionic liquids with different anions was found to have the same value, 115 cm3/mol at 298.15 K. The intrinsic volume of BMIM+ cation estimated from quantum chemical calculations at the M062X/6‑311++G(d,p) theory level exceeds one obtained from density experiment indicating that solvation of cation has a negative contribution to the volume of ion in propylene carbonate. In order to investigate the microscopic structure of the BMIM+ solvation shell in PC, molecular dynamics simulation of the infinitely dilute solution was carried out in the NVT ensemble at 298.15 K. The results of the simulation reveal that 5-6 PC molecules forming the first solvation shell penetrate into the inner space of the cation, which agrees with the results of a density experiment treatment. From the analysis of the cation-solvent site-site radial distribution functions and the running coordination numbers it was established that the most probable coordination center of PC molecule is carbonyl oxygen.

Solubility of nonpolar gases in 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoropropan-2-ol at several temperatures and 101.33 kPa partial pressure of gas

2001 ◽  
Vol 79 (10) ◽  
pp. 1460-1465 ◽  
Author(s):  
Miguel Angel Sánchez ◽  
Ana María Mainar ◽  
Juan Ignacio Pardo ◽  
María Carmen López ◽  
José Santiago Urieta
Keyword(s):  
Partial Pressure ◽  
Thermodynamic Functions ◽  
Partial Molar Volumes ◽  
Scaled Particle Theory ◽  
Particle Theory ◽  
Molar Volumes ◽  
Gas Solubilities ◽  
Enthalpy And Entropy ◽  
Solubility Of Nonpolar Gases

Solubilities, expressed as mol fractions, of 14 nonpolar gases (He, Ne, Ar, Kr, Xe, H2, N2, O2, CH4, C2H4, C2H6, CO2, CF4, and SF6) in 2,2,2-trifluoroethanol (TFE) at 268.15 and 283.15 K and 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) at 273.15 and 283.15 K, with the partial pressure of gas being 101.33 kPa for all measurements, are reported. Standard changes in the thermodynamic functions (enthalpy and entropy) have been calculated from the solubilities and their variation with temperature. The Scaled Particle Theory (SPT) model has been used to determine these thermodynamic functions and also the partial molar volumes of the gases in the formed solutions.Key words: gas solubilities, nonpolar gases, fluoroalcohols, Scaled Particle Theory.

Partial molar volumes of acidic gases in physical solvents and prediction of solubilities at high pressures

1992 ◽  
Vol 70 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Yuming Xu ◽  
Lili Li ◽  
Loren G. Hepler
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Sulfur Dioxide ◽  
Molar Volume ◽  
Propylene Carbonate ◽  
Infinite Dilution ◽  
High Pressures ◽  
Partial Molar Volumes ◽  
Molar Volumes ◽  
Acidic Gases

Partial molar volumes at infinite dilution for three acidic gases (carbon dioxide, hydrogen sulfide, and sulfur dioxide) in four physical solvents (propylene carbonate, methyl cyanoacetate, N-formyl morpholine, and Selexol) have been obtained using our new dilatometer. These partial molar volumes, in combination with the Henry's law constants obtained previously, have been used in the Krichevsky–Kasarnovsky equation for predicting the solubilities of acidic gases in physical solvents at high pressures. Keywords: partial molar volume, solubility, physical solvents.

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