The photoexcitation, relaxation, and optical erasure regimes of spiropyran- (SP-) doped polymer films were studied. Cellulose acetate, poly(vinyl acetate), and poly(methyl methacrylate) (PMMA) were used as host polymer matrices. We studied the character of the photoreaction for both coloring and bleaching processes. Reversible holographic recording in SP-PMMA films and the origin of the photochemical fatigue was studied upon repeated UV-visible irradiation cycles.

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The photo excitations of Spiropyran-doped polymer films were studied. Cellulose acetate (CA), commercial ploy(methyl methacrylate) (PMMA) and PMMA prepared by radical polymerisation of MMA, were used as host polymer matrices. The open form of SP presents a maximum of absorption cantered at about 600 nm upon UV irradiation. We have determined the photoreaction rate constants, kuv and k15, for the coloring and bleaching processes. Reversible holographic recording in SPIPMMA films was studied and photochemical fatigue resistance was evaluated upon repeated UVfVisible irradiation cycles. We found a loss of 42, 53 and 74% respectively in PMMA by gravity deposition, PMMA (by polymerisation of MMA) and cellulose acetate films.