This project deals with some of the fundamental aspects of gel technology. Characterization studies to determine interaction parameters of polymers with solvents, degree of cross-linking, preferential adsorption in mixed solvents, and, when necessary, ionic charge, are carried out to make qualitative predictions based on classical thermodynamic equations for gels. The experimental results obtained on macroscopic gels are then used to determine the role played by surface forces and particle size on the swelling behavior of microgels. The reverse emulsion and suspension polymerization technique is used to prepare microgels with controlled properties of size, cross-linking density, and degree of swelling during polymerization. The microgel properties of primary importance to be investigated are their thermodynamic swelling properties and their rheological and mechanical properties which govern many of the practical and industrial usages of these systems.
