Photochromic Properties of Spiropyran in Polymeric p–Conjugated Matrices
Martin Vala, Martin Weiter, Gabriela Tajtrova, Stanislav Nespurek, Petr Toman and Juliusz Sworakowski
The contribution reports the results of studies of the photochromic reaction of 6-nitro-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indoline] (SP) in poly(methyl methacrylate) and in p conjugated photoconductive polymer matrices based on poly(p-phenylene vinylene) derivatives. The polymer matrix strongly influences the reaction rate, lifetime of coloured species and the value and distribution of activation energies of the bleaching process. It was also found that the activation energy depends on the intensity of light used for photochromic conversion and the exposure time. Photochromic reaction is influenced by energy transfer processes between the conjugated chain and photochromic additive.