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TitleTriplet state energy and electron transfer in coronene-doped polymethylmethacrylate
Publication TypeJournal Article
Year of Publication2003
AuthorsSmith, G.J., Dunford C.L., Woolhouse A.D., Haskell T.G., and Barnes T.H.
JournalJournal of Photochemistry and Photobiology A: Chemistry
Pagination267 - 272
Date Published2003
ISSN10106030 (ISSN)
Keywordsarticle, chemical reaction kinetics, electron transport, energy transfer, high temperature, phosphorescence, photochemical quenching, photochemistry, photodegradation, poly(methyl methacrylate), polymer, temperature dependence
AbstractThe phosphorescence yield and decay kinetics of coronene in deoxygenated polymethylmethacrylate (PMMA) have been determined over the temperature range 77-300 K. At temperatures below ∼200K the decays were close to single exponential (lifetime = 9.3 s at 77 K). However, at higher temperatures the decays were best fitted by the function I (t) = I0 exp(at + btn), where 0.3 < n < 0.4. This kinetic behaviour is attributed to long range energy transfer via a number of steps following a quasi-one-dimensional random walk from the coronene triplet state to trap sites. Discontinuities were observed in the temperature dependence of the phosphorescence yield of coronene in polymethylmethacrylate at temperatures of 175 and 255 K, corresponding to the onset of rotations within the polymer molecule. © 2003 Elsevier Science B.V. All rights reserved.

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