title: Mechanism of wavelength conversion in polystyrene doped with benzoxanthene: emergence of a complex.
abstract: Fluorescent guest molecules doped in polymers have been used to convert ultraviolet light into visible light for applications ranging from optical fibres to filters for the cultivation of plants. The wavelength conversion process involves the absorption of light at short wavelengths followed by fluorescence emission at a longer wavelength. However, a precise understanding of the light conversion remains unclear. Here we show light responses for a purified polystyrene base substrates doped with fluorescent benzoxanthene in concentrations varied over four orders of magnitude. The shape of the excitation spectrum for fluorescence emission changes significantly with the concentration of the benzoxanthene, indicating formation of a base substrate/fluorescent molecule complex. Furthermore, the wavelength conversion light yield increases in three stages depending on the nature of the complex. These findings identify a mechanism that will have many applications in wavelength conversion materials.
authors: 1] Kyoto University, 2 Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan [2] National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors: Hidehito
authors: H
authors: Nakamura
authors: Yoshiyuki
authors: Y
authors: Shirakawa
authors: Hisashi
authors: H
authors: Kitamura
authors: Nobuhiro
authors: N
authors: Sato
authors: Osamu
authors: O
authors: Shinji
authors: Katashi
authors: K
authors: Saito
authors: Sentaro
authors: S
authors: Takahashi
mesh_terms: D005456:Fluorescent Dyes / Q000138:chemical synthesis*; D008422:Materials Testing; D011137:Polystyrenes / Q000138:chemical synthesis*; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D011137:Polystyrenes; D014966:Xanthenes
references: Nat Mater. 2008 May;7(5):343-5
references: 18432200
references: Appl Radiat Isot. 2013 Oct;80:84-7
references: 23845742