Microgels

Microgels have now been in use for a number of years as rheological modifiers in coatings. During this project, the effects of dissolved free polymer on microgel particles to give fine rheological control were investigated. Free polymer may interact with the microgel particles in several ways: the polymer may be absorbed into the particles; it may be depleted leading to particle aggregation; or it may have an osmotic deswelling effect on the microgel particle dimensions.

Microgels were prepared in aqueous and non-aqueous media and suitable free polymers prepared. The degree of absorption of the free polymer was determined by monitoring the concentration of polymer in solution using conventional analytical techniques and nuclear magnetic resonance spectroscopy. Depletion flocculation and changes in microgel particle dimensions were monitored turbidimetrically and by dynamic light scattering respectively. The rheological properties of the microgel systems were investigated.

PRA co-ordination the project whilst the bulk of the practical was carried out in the laboratories of the University of Bristol under the supervision of Professor Brian Vincent.

Further Information

If you are interested in this, or any other project, please contact Richard Holman.