POLYMER DIFFUSION-LIMITED INTERACTIONS STUDIED BY LUMINESCENCE QUENCHING.

Diffusion-limited interactions and reactions between small molecules, between small molecules and polymers, and between polymers themselves often occur in polymer solutions. In this particular study, work has been limited to the study of small molecule-small molecule interactions and small molecule-polymer interactions although in the future we hope to study polymer-polymer interactions of the type which are involved in the termination reaction of free radical polymerization. This diffusion-limited reaction is very important in autoacceleration phenomena or the 'gel' effect. Phosphorescence and fluorescence quenching can be used as a tool to study diffusion-limited interactions between a chromophore and a quencher moiety in polymer solutions. Horie and Mita have done limited studies involving phosphorescence quenching of benzil by anthracene and of benzil by anthracene-labeled polystyrene. In the present study, similar techniques are employed to study interactions as a function of inert polymer concentration, polymer MW, polymer species, solvent, and location of the quencher label on the polymer. The results of this study can be successfully interpreted in terms of the Duda-Vrentas free volume theory.