SYNTHESIS AND SOLUTION CHARACTERIZATION OF PYRENE-LABELED POLYACRYLAMIDES

A new pyrene-containing acrylamido monomer, [1-(beta-aminoethyl) sulfonamidopyrene] acrylamide (APS) has been synthesized and carefully purified for copolymerization and subsequent photophysical studies. Pyrenesulfonamide-labeled acrylamide copolymers were prepared in homogeneous and microheterogeneous (surfactant) solutions utilizing free radical polymerization techniques. A comparatively blocky microstructure is suggested for the surfactant-polymerized sample relative to the solution-polymerized material as evidenced by enhancement of excimer to monomer intensity (I(E)/I(M)) for the former. I(E)/I(M)) varies with concentration for both polymer samples in H2O, reflecting intermolecular hydrophobic interactions of the pyrenesulfonamide labels. Pyrenesulfonamide ground-state aggregates are denoted by excitation spectra. Correlation of polymer dilute solution rheological behavior with the photophysical response of the pyrenesulfonamide label can be related to the degree of intramolecular association.