US EPA

1172179 

Journal Article 

Photophysical properties of a quinoline derivative in polymer matrices 

Rogge, C; Ahmad, SR 

2000 

Yes 

Journal of Optoelectronics and Advanced Materials
ISSN: 1454-4164 

2 

3 

247-254 

English 

WOS:000089455700005 

The photophysical properties of a quinoline derivative were studied to evaluate its use as a marker for the optical identification and subsequent automatic sorting of polymers. The steady state fluorescence spectra and fluorescence lifetimes of the derivative in additive-free PVC and commercial-grade HDPE are reported. The fluorescence properties of the dye in PVC, which contained an optical brightener and a light stabiliser, and in methanol and cyclohexane were also studied. The results show that, the steady state fluorescence characteristics of the dye, attributed to an excited state intramolecular proton transfer (ESIPT) process, are nearly independent of the environment. The emission peak wavelength was found to vary between 514 nm (in methanol) and 521 run (in PVC). The results of fluorescence lifetime measurements strongly indicate that hydrogen bonding leads to non-radiative deactivation of the excited dye molecules. The fluorescence lifetime of the dye in cyclohexane, PVC and HDPE ranges from approximately 3.7 ns to 4.2 ns, but in methanol is reduced to a value beyond the time resolution limits of the setup employed. A strong decrease in the fluorescence quantum yield of the dye in this solvent is also observed. 

fluorescence spectroscopy; decay kinetics; polymer; dye