In traditional theories for electrolyte solutions the solvent is treated only as a dielectric continuum. A more complete theoretical picture of electrolyte solutions can be obtained by including the solvent as a true molecular species. In this thesis we report results for the structural, thermodynamic, and dielectric properties of model electrolyte solutions which explicitly include a water-like molecular solvent. The ions are modelled simply as charged hard spheres and only univalent ions are considered. The water-like solvent is also treated as a hard sphere into which the low-order multipole moments and polarizability tensor of water are included. The reference hypernetted-chain theory is used to study the model systems. The formalism of Kirkwood and Buff is employed to obtain general expressions relating the microscopic correlation functions and the thermodynamic properties of electrolyte solutions without restricting the nature of the solvent. The low concentration limiting behaviour of these expressions is examined and compared with the macroscopic results determined through Debye-Hückel theory. The influence of solvent polarizability is examined at two theoretical levels. The more detailed approach, the R-dependent mean field theory, allows us to consider the average local electric field experienced by a solvent particle as a function of its separation from an ion and is shown to have an effect upon the limiting laws of some thermodynamic properties. Model systems for liquid water are investigated over a large range of temperatures and pressures and are found to have dielectric constants which agree reasonably well with experiment. Model aqueous electrolyte solutions are studied both at infinite dilution and at finite concentration, but only at 25°C. The equilibrium dielectric constants of these solutions are qualitatively consistent with those of experiment. A remarkable diversity of behaviour is obtained for our model solutions by simply varying the hard-sphere diameters of the ions. In many cases the behaviour observed for thermodynamic quantities is in accord with experiment. The ion-ion, ion-solvent and solvent-solvent correlation functions of the solutions are examined in detail, revealing a wealth of structural information. Ionic solvation is generally found to be very sensitive to the details of the interactions within the system. / Science, Faculty of / Chemistry, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/27365 |
| Date | January 1987 |
| Creators | Kusalik, Peter Gerard |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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