The reversible reaction that takes place in the writable, readable, erasable (WRE) photosensitive materials involving fulgides (ABERCHROM 540 and 670) was investigated with a photochemical and holographic approach. It appeared that the fatigue of the photosensitive material was strongly dependent on the properties of the matrix used as a support. This was precisely established both by spectroscopic monitoring (λmax, absorbancemax, photo-stationary state) and by following the diffraction efficiency η values. There was a nice correlation between the evolution of the spectral features of C isomer and of the η values all along the WRE cycles. This combined approach was applied to four different supports: PVK, PMMA, PEPC/PS and epoxy RESIN. So for both fulgides: (1) PVK, frequently used in optics, appears as being the worst one. The starting fulgides were destroyed after only a few WRE cycles. This was assigned to the intrinsic photoaging of PVK whose absorption in UV domain is far from negligible and leads to the formation of radical species able to attack the fulgide. (2) Holograms recorded in PMMA and PEPC/PS present similar behavior with a loss of ≈10% after 8 cycles. (3) Epoxy RESIN appears to be a very good candidate for these reversible systems; no fatigue was observed after 40 cycles. It has to be attributed to the matrix in which the detrimental rotation process, giving rise to the non photochromic Z isomer, is strongly inhibited.
[1]
G. Derderian,et al.
Investigation of the Photophysical Processes and Photochemical Reactions Involved in PVK Films Irradiated at λ > 300 nm
,
2003
.
[2]
Wayne E. Jones.
Photochromism: Molecules and systems: Edited by H. Dürr and H. Bouas-Laurent. Elsevier, Amsterdam, 1990, 1068 pp. US$297.50/Dfl. 580.00. ISBN 0-444-87432
,
1995
.
[3]
Gurusamy Manivannan,et al.
Holographic and spectroscopic characterization of spiropyran doped poly(methyl methacrylate) films
,
1994
.
[4]
N. Singh,et al.
Picosecond Dynamics of Bragg Grating Formation in the Fulgide E-α-(2,5-Dimethyl-3-furyl)ethylidene(dicyclopropylmethylene)-2,5-furandione
,
1996
.
[5]
Gurusamy Manivannan,et al.
Spiropyran-doped poly(vinyl carbazole): a new photopolymer recording medium for erasable holography
,
1995
.
[6]
Michel Bolte,et al.
Characterization of dye-doped PMMA/PVK films as recording materials
,
1998,
Other Conferences.