Temperature dependence of electronic energy transfer and quenching in copolymer films of styrene and 2-(2'-hydroxy-5'-vinylphenyl)-2H-benzotriazole

Quenching of the emission of both the polystyrene monomer and the excimer for a series of varying composition copolymer films of styrene and 2-(2'-hydroxy-5'-vinylphenyl)-2H-benzotriazole is reported. The preponderance of quenching for both the monomer and excimer emissions is due to interception of the migrating excitation at the quencher site, although additional quenching results via long-range dipole-dipole energy transfer from the monomer and excimer traps to the quencher trap. The quenching of the monomer fluorescence and phosphorescence and that of the excimer fluorescence were found to be temperature independent over the ranges 14-58 and 191-296 K, respectively. Most significantly, it is concluded that the energy migration process is temperature independent over the range 14-296 K.