Surface and Colloid Chemistry

Dr. D.W. Thompson

My principal research interests are in the physical and chemical properties of particle surfaces and the properties of colloidal dispersions. The main emphasis is on the properties of mineral particles; their influence on environmental chemistry, and their behaviour in industrial and technological processes.

The formation of mineral particles.

Materials such as metal oxides, sulphides and carbonates are formed by chemical and biological processes in soils and natural waters. These materials markedly influence the chemical composition of natural waters through adsorption and co-precipitation processes. Studies are made of processes involved in mineral formation and the influence of reaction conditions on the surface chemical properties of the mineral particles.

Adsorption processes.

Natural particles can remove large amounts of chemical species from natural waters by the process of adsorption and thus substantially influence natural chemical and biological processes.

In many industrial and technological processes the surfaces of particles are "conditioned" by the controlled adsorption of ions and molecules, in order to optimise properties such as dispersability and flow characteristics. Adsorption studies are carried out in order to elucidate the mechanisms and extents of adsorption under different conditions.

Particle aggregation.

Particle aggregation is of importance in nature where it influences the formation of natural water sediments and the structure and fertility of soils. In many industrial and technological processes particle aggregation behaviour is of crucial importance, for example in mineral mining and in the production of paints, cosmetics and pharmaceutical preparations. Studies are made of the fundamental mechanisms of particle aggregation and of the structures of aggregates formed in different ways.

Previous Stage III project titles include:

  1. The adsorption of copper in mixed dispersions of manganese and titanium oxides.
  2. The hydration of Portland cement.
  3. Heteroaggregation in dispersions of silicon and iron oxides.
  4. Release of calcium, phosphate and lead from iron oxides in aqueous solutions.
  5. The hydrolysis of iron in clay dispersions.
  6. Morphology and surface electrical charge characteristics of calcium carbonate minerals.
Some recent references:
  1. Colloids and Surfaces, (1991) 60 369; (1992) 62 163; (1993) 73 103;
  2. J.Colloid Interface Sci., (1992) 152 197; (1992) 151 236;
  3. Environ.Technol., (1993) 14 367.