Diffusion-controlled interactions between small molecules, between polymers, and between small molecules and polymers are studied by a combination of fluorescence and phosphorescence quenching experiments and excimer fluorescence. These studies will yield information related to polymerization kinetic parameters and, in particular, will allow for an investigation of how various polymer solution variables such as molecular weight, concentration, and polymer-solvent compatibility control the onset of the 'gel' effect. Furthermore, these studies lead to a greater fundamental understanding at a molecular level of polymer diffusion processes, Rouse dynamics and dynamics of entangled polymers, and the structure of polymer solutions. Photophysical studies such as fluorescence quenching are key to the success of this research.
