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

In order to try to explain some of the rather surprising features of reactions in frozen solutions, four different systems are extensively studied. They are the reaction of methyl iodide with triethylamine to form the quaternary ammonium salt in frozen benzene, the base catalyzed decomposition of t-butyl-peroxy formate to carbon dioxide and t-butyl alcohol in frozen p-xylene, the reaction of ethylene chlorohydrin with hydroxide ion to form ethylene oxide in frozen aqueous solution and the mutarotation of glucose in ice. In addition, a demonstration experiment is presented in which iodide ion is oxidized to iodine by arsenic acid in frozen aqueous solution. Several new features of reactions in frozen solutions are reported; including a maximum in the rate - temperature dependence curve, rate enhancements as large as 1000 - fold over reaction in unfrozen solutions and shifts in the equilibrium position. Kinetic equations are developed which correlate all of the results and which also explain some of the observations of other investigators. These equations are based upon the assumptions that (1) when a solution containing reactive species is frozen all of the reactants as well as any other solutes present are rejected by the crystallizing solvent and are concentrated into regions which remain liquid and that (2) the reaction proceeds normally in these regions. The fundamental equation used for correlating the rate data for the second-order reactions studied is, [formula omitted] where Vn is the total volume of the liquid regions, mA is the total moles of reactant A present in the system at any time and Ah and Bh are the concentrations of the reactants A and B in the liquid regions. The ideas developed for the treatment of reactions in frozen solutions are extended to reactions in organic solids which have a melted phase present. This treatment accounts qualitatively for the observations made on mutarotation in solid glucose. The application of the method to the isomerization of 5-norbornene-2,3-endo-dicarboxylic/anhydride to the exo-isomer allows separation of concurrent reactions in the melt and in the solid. / Science, Faculty of / Chemistry, Department of / Graduate

This thesis is concerned with investigating the suitability of room temperature ionic liquids as solvents in which to perform voltammetry, and in characterising electrochemical processes within these media. After providing a general introduction and a background to the ionic liquid field, the results of six original studies are presented, dealing in turn with the following subjects: • The oxidation of N,N,N',N'-tetraalkyl-para-phenylenediamine (TAPD) in five ionic liquids each incorporating the bis(trifluoromethylsulfonyl)imide anion. • The reduction of oxygen in four ionic liquids based on quaternary alkyl -onium cations and heavily fluorinated anions in which the central ion is either nitrogen or phosphorous. The simulation of double potential step chronoamperometry at a disk electrode for the case of unequal diffusion coefficients and its experimental validation using a variety of aqueous, traditional nonaqueous and ionic liquid solutions. • The rate of diffusion of N,N,N',N'-tetramethyl-para-phenylenediamme (TMPD), its radical cation and dication as a function of temperature and ionic liquid viscosity and four such solvents. • The temperature dependence of the viscosity of five ionic liquids along with the translational and rotational diffusion coefficients of dissolved 2,2,6,6- tetramethylpiperidine-N-oxyl (TEMPO). • The kinetics of the reaction between N,N-dimethyl-para-toluidine (DMT) and its electrogenerated radical cation in an ionic liquid solvent. The experimental strategy common to each report involves the application of cyclic voltammetry and chronoamperometry at disk electrodes immersed in uL-samples of ionic liquid solution. The data so measured is then analysed via the appropriate theoretical equations or, as is commonly necessary, by comparison with simulated voltammetry. Combined, these chosen redox systems provide access to information on various aspects of electrochemistry within ionic liquids, specifically (a) mass transport (b) the nature of the electron transfer process and (c) the rate of follow-up homogeneous reactions. It is the overall finding herein that while both diffusion and heterogeneous electron transfer are significantly slowed relative to the same processes in a conventional organic solvent, the rate of subsequent homogeneous chemistry remains largely unchanged.

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From Introduction Chlorbutol , which is tri-chlor-tertiary-butanol, was first prepared by Willgerodt in 1886 (1). The reaction he used for its preparation is still used today, though slightly modified (2)(3)(4), and is suggested by its original name "acetone-chloroform". The substance was prepared by adding solid potassium hydroxide to a cold mixture of acetone and chloroform (5 ). Chlorbutol is a derivative of the trichlorinated derivative of methane, and its formation may best be described by the use of structural formulae.

Published Article / The world seems to be an increasingly fast-changing place with many societal trends coming and going each year. However, some world-wide trends seemed to have established themselves as being more long-term in nature, e.g. more widespread expectation of global warming, increasing fear of terrorism and globalisation of economies. Other trends are largely confined to the industrialised economies of North America, Europe and the Pacific Rim. Examples include an ageing population, more demanding customers and increasing disposable income. Different trends will be seen in other regions. The impact of these trends upon designers and design cannot be overstated. They will affect the way consumers purchase, use and dispose of products. The types of products that consumer's buy and the features they will require from their products will change. Designers must respond to this with innovative product designs that make optimum use of the already scarce natural resources available. Likewise, engineers must be innovative in their task of converting these designs into reality. <br>This paper seeks to identify some of the trends that will have most impact upon product design in a number of global regions. The responses that designers could (or should) make to these are listed together with some examples of products that illustrate the issues involved. The impact upon the way designers think and how they need to be educated is also discussed. Finally, designers' ideas are only pipedreams until they are transformed into reality through the effort of various types of engineers. The paper concludes by describing some of the new challenges that engineers will face as they play their role in responding to global and regional trends. It is highly likely that the challenges will vary somewhat from one region to the next and so it is crucial that locally-adapted solutions are implemented.

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There are many methods for solving polynomial equations. Dating back to the Greek and Babylonian mathematicians, these methods have been explored throughout the centuries. The introduction of the Cartesian Coordinate Plane by Rene Descartes greatly enhanced the understanding of what the solutions actually represent. The invention of the graphing calculator has been a tremendous aid in the teaching of solutions of polynomial equations. Students are able to visualize what these solutions represent graphically. This report explores these methods and their uses. / text

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