Comparison of the thermodynamic and transport properties of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) with LiClO4 and Bu4NBr in water at 25 °C

1997 ◽  
Vol 75 (11) ◽  
pp. 1608-1614 ◽  
Author(s):  
Gérald Perron ◽  
Dany Brouillette ◽  
Jacques E. Desnoyers
Keyword(s):  
Phase Diagram ◽  
Surface Tension ◽  
Heat Capacity ◽  
Tetrabutylammonium Bromide ◽  
Lithium Perchlorate ◽  
Mass Action ◽  
Volume Heat ◽  
Action Model ◽  
Self Association ◽  
Solid Liquid

Lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) is a promising electrolyte for lithium batteries. While it presents many interesting features in aprotic solvents (high solubility and conductivity, electrochemical stability, etc.), little is known about its properties in water. The solid–liquid phase diagram, surface tension, volume, heat capacity, and conductivity were therefore measured at 25 °C and compared with the same properties of typical hydrophilic (LiClO4) and hydrophobic (Bu4NBr) electrolytes. To help in the comparison, some of the literature data for LiClO4 and Bu4NBr were extended. The standard Λ0, [Formula: see text] and [Formula: see text] are respectively 71.12 S cm2 mol−1, 139.7 cm3 mol−1 and 543 J K−1 mol−1at 25 °C. LiTFSI s quite soluble, and shows surface activity and a small tendency for self-association in water. The aggregation number estimated from a mass-action model is of the order of 4. Keywords: lithium bis(trifluoromethylsulfonyl)imide, lithium perchlorate, tetrabutylammonium bromide, volume, heat capacity, phase diagram, thermal analysis, surface tension, conductance.

A study of micellization and the thermodynamic properties of a series of aqueous sodium cyclohexyl alkanoate surfactants

2000 ◽  
Vol 78 (9) ◽  
pp. 1222-1232
Author(s):  
Judith A MacInnis ◽  
D Gerrard Marangoni ◽  
R Palepu
Keyword(s):  
Surface Tension ◽  
Thermodynamic Properties ◽  
Speed Of Sound ◽  
Mass Action ◽  
Aggregation Numbers ◽  
Mass Action Model ◽  
Efficiency And Effectiveness ◽  
Action Model ◽  
Ft Ir ◽  
Density Surface

The micellization and the thermodynamic properties of a series of sodium cyclohexyl alkanoates of the general formula C6H11(CH2)nCOONa (where n = 1, 2, 3, 4) were investigated employing conductivity, density, surface tension, viscosity, speed of sound, luminescence probing experiments, and Fourier transform infrared (FT-IR) spectroscopy. The critical micelle concentrations (cmcs) and the aggregation numbers indicate that these surfactants have high cmc values and low aggregation numbers when compared to other single-headed surfactants (most notably the sodium alkanoates). Thermodynamic properties, obtained from the mass action model, indicate that micellization is spontaneous and entropically driven. The saturation area per molecule, the free energies of adsorption, and the efficiency and effectiveness of adsorption were determined through surface tension measurements. The presence of the cylcohexyl ring appears to influence the surface properties of micellization. Both the effectiveness and the efficiency of these surfactants, in lowering the surface tension of water, are lower than that of the straight chain alkanoates.Key words: thermodynamics, micellization, aggregation numbers, speed of sound, and spectroscopy.

Modelling and Experimental Studies of Sorption in the Near Field of a Cementitious Repository

1989 ◽  
Vol 176 ◽  
Author(s):  
P.L. Brown ◽  
A. Haworth ◽  
R. McCrohon ◽  
S.M. Sharland ◽  
C.J. Tweed
Keyword(s):  
Near Field ◽  
Experimental Studies ◽  
Mass Action ◽  
Chemical Equilibria ◽  
Transport Code ◽  
Mass Action Model ◽  
Action Model ◽  
Modelling Studies ◽  
Simple Mass

ABSTRACTA joint experimental and modelling programme is reported, which aims to improve our understanding of sorption processes of radionuclides onto repository materials. Diffusion/sorption experiments of sorption onto cement are described, although results are limited at this stage. The modelling studies use the coupled chemical equilibria and transport code CHEQMATE to simulate some of these experiments. The chemical part of the model is based on a simple mass-action model of sorption. More detailed comparisons will continue when the experiments are terminated, and the samples are sectioned.

Sign in / Sign up

Export Citation Format

Share Document