title: Photodegradation of polymer-dispersed perylene di-imide dyes.
abstract: Polymer-dispersed perylene di-imide dye photodegradation is investigated by monitoring the fluorescence intensity as a function of 532 nm laser pulses. Anaerobically irradiated polymer-dye films exhibited an accelerated decrease in fluorescence intensity, which was partially recovered upon exposure to oxygen. Decelerated photodegradation rates were observed for perylene di-imide ethanol solutions upon the addition of a singlet oxygen quenching antioxidant. These observations suggest reversible photoreduction and type II photo-oxidation as important photodegradation mechanisms. Type II photo-oxidation for perylene red 532 nm irradiation is supported by a singlet oxygen quantum yield of 0.09+/-0.03, determined via detection of time-resolved O2 (a1delta(g) --> X3sigma(g)-) infrared phosphorescence.
authors.affiliation: Department of Environmental Science and Technology, Shinshu University, Nagano, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Nikolay
authors.initials: N
authors.lastname: Barashkov
authors.forename: Jerry
authors.initials: J
authors.lastname: Heath
authors.forename: Wade N
authors.initials: WN
authors.lastname: Sisk