Professor Glenn Hefter

Room: S&C/3.041B

Research

Solution chemistry: particularly the properties and behaviour of electrolyte solutions at high temperatures, in complex mixtures of industrial and environmental interest, and in nonaqueous solvents; new experimental methods such as dielectric relaxation spectroscopy and flow techniques.

Projects

High Temperature Electrolyte Solutions

The properties of electrolyte solutions at high temperatures are of enormous economic importance in the minerals, oil and other industries. World class facilities exist in my labs for the measurement of heats of reaction, heat capacities, densities and Raman and UV-Visible spectra at temperatures up to 300°C. They are used to study systems of scientific and industrial importance, ranging from simple electrolytes to complex hydrometallurgical mixtures.

Dielectric Relaxation Spectroscopy

Dielectric relaxation (DR) spectroscopy is an extremely powerful technique for the study of chemical species in solutions. It provides insights into the structure, stability and dynamics of systems at the nano-level and on the pico-second timescale. State-of-the-art DR measurements are made in my labs on electrolyte and non-electrolyte solutions to study the behaviour of ions, complexes, polymers and micelles. This work involves extensive collaboration with, and the opportunity to work in, overseas Universities.

Hofmeister Effects in Chemistry & Biology

Hofmeister (or specific ion) effects are ubiquitous throughout chemistry and especially biology. They are believed to play an important role in areas as diverse as the measurement of pH and the action of proteins. Yet our understanding of these effects has hardly improved since their discovery over 100 years ago. This project will use a combination of pH and dielectric relaxation to gain detailed insights into these mysterious effects
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Solvation of Ions

Solvation governs the behaviour of ions in solution, including their ability to form complexes and micelles, and their redox and acid/base properties. Yet surprisingly few quantitative data are available for most ions, particularly outside of water. Projects in this area are focused on both simple and complex ions associated with their practical applications in batteries and hydrometallurgy. A variety of techniques are used, including spectroscopy (NMR, Raman, DR, etc.) potentiometry, calorimetry, viscometry, and densitometry.

Molecular Sieves

Molecular sieves are complex alumino-silicates that are the preferred drying agents for most liquids. They are cheap, fast, effective and re-useable. Although molecular sieves contaminate solvents during the drying process, almost nothing is known about such effects. This project aims to quantify the extent of this contamination using a variety of modern analytical techniques.

Heat Capacities and Volumes of Electrolytes

Heat capacities and volumes are fundamental thermodynamic properties of electrolyte solutions but also sensitive probes of ion-solvent-solvent interactions. These properties are easily and accurately measured using a special micro-flow apparatus. Current areas of interest include simple and micellar electrolytes and mixtures of hydrometallurgical interest.

Solubilities of Hydrocarbons in Water and Sea water

Accurate knowledge of hydrocarbon solubilities in water and seawater is needed for the oil extraction industry and for understanding their environmental impacts. However, little reliable information is available. This project involves the use of sensitive analytical techniques to measure the solubilities of a range of key hydrocarbon pollutants under conditions of temperature and salinity typical of marine and estuarine environments.

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