PHOTOPHYSICAL STUDY OF PYRENE-LABELED ST DVB COPOLYMERS

The photophysical properties of a series of pyrene-labelled styrene/di vinyl benzene (St/DVB) copolymers have been studied for the first time by steady-state fluorescence spectra. The results indicate that when pyrenyl content (mol%) in the copolymer is lower than 0.006%, the fluo rescence spectra only show the pyrenyl monomer emission, while the 0-0 transition band is much suppressed and the vibronic structure is part ially lost. However, in the fluorescence spectra of the copolymers wit h pyrenyl content higher than 0.3%, there appear some new emission ban ds at ca 420 nm, 440 nm and 475 nm. These results are explained in ter ms of the formation of ground-state and excited-state aggregates, whic h reveals the heterogeneity of the crosslinked networks.