Preparation and photochromism of sulfonated spiropyran-silica nanocomposites

Tagaya, Hideyuki; Nagaoka, Takeshi; Kuwahara, Tsuneo; Karasu, Masa; Kadokawa, Jun‐ichi; Chiba, Koji

doi:10.1016/s1387-1811(98)00062-6

Cited by 27 publications

(27 citation statements)

References 14 publications

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“…Figure 3 shows the decoloration kinetics of the free spiropyran. It is known that in polar environments, the open merocyanine form is stabilized and vice versa 31. As expected, the polar mica particles retarded the relaxation of the zwitterionic colored merocyanine species in switching back to the nonpolar colorless spiropyran.…”

Section: Resultssupporting

confidence: 66%

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Synthesis of high‐molecular‐weight linear methacrylate copolymers with spiropyran side groups: Conformational changes of single molecules in solution and on surfaces

Adelmann

Mela

Gallyamov

et al. 2009

J. Polym. Sci. A Polym. Chem.

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P(BMA-co-HEMA-spiropyran) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization of butyl methacrylate (BMA) and 2-(trimethylsilyloxy)-ethyl methacrylate (HEMA-TMS), removal of the TMS-protective groups, and the polymer analogous esterification of the hydroxyethyl side chains with a spiropyran containing a carboxylic acid group. UV-induced conformational changes of the synthesized macromolecules and low-molecular-weight spiropyran molecules were studied. Rate constants and half-life times of the ring closure reaction from zwitterionic merocyanine to the spiropyran species were determined in the presence and absence of mica-dispersed particles in toluene both with the free spiropyran and the polymer-bound spiropyran. Scanning force microscopy was used to visualize the conformation of spiropyran-decorated single macromolecular chains and agglomerated polymer-bound merocyanine adsorbed on mica.

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Section: Resultssupporting

confidence: 66%

“…A polar environment stabilizes the charged structure of the merocyanine form. It is known that for the reversible switching of free spiropyrans adsorbed on a silica matrix, a coexistence of polar and nonpolar regions on the matrix (e.g., toluene) is essential 31, 36, 37…”

Section: Resultsmentioning

confidence: 99%

Synthesis of high‐molecular‐weight linear methacrylate copolymers with spiropyran side groups: Conformational changes of single molecules in solution and on surfaces

Adelmann

Mela

Gallyamov

et al. 2009

J. Polym. Sci. A Polym. Chem.

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“…Photochromic molecules, accommodated in porous silicates, have been studied with respect to the influence of host-guest interactions on the photoprocesses, giving indications for strongly increased lightfastness. [7][8][9][10] Also, enhanced stability against thermal relaxation and improved photoswitching reversibility are observed for spiropyran derivatives in porous silica and faujasite, [11,12] or for azobenzene in the zeolite ZSM-5 and in microporous aluminophosphate AlPO 4 -5. [13,14] In contrast, fast thermal relaxation was observed when embedding photochromic molecules in the hydrophobic parts of template-containing Si-MCM-41 thin films.…”

Section: Introductionmentioning

confidence: 94%

“…As it was shown that spiro-dyes exhibit strong matrix effects, e.g., in porous silicates, [11,12,[23][24][25][26][27][28] we chose to analyze the matrix effects on the thermal fading behavior of a representative spirooxazine dye, 5-chloro-1, (1,4)oxazine], encapsulated in functionalized mesoporous silicates. In particular, two effects were studied that influence the fading speed of the encapsulated dye ( Fig.…”

Section: Introductionmentioning

confidence: 99%

Tuning the Thermal Relaxation of a Photochromic Dye in Functionalized Mesoporous Silica

Mühlstein

Sauer²,

Bein

2009

Adv Funct Materials

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In this study, it is shown that the kinetics of the back‐switching reaction of a photochromic spirooxazine dye encapsulated in mesoporous silica materials can be significantly influenced both by the space available to the dye molecules and by the functionalization of the silica wall. Steric hindrance of the ring‐closing process due to high dye content or small pore size leads to a slow fading speed of the irradiated dye species. Further, the density of surface silanol‐groups present at the silica walls has an effect on the switching behavior of the dye because of their ability to stabilize the zwitterionic merocyanine isomers, thereby slowing the fading process from the open to the closed form. This stabilization effect is further enhanced in the presence of acidic functional groups, while, in contrast, basic functional groups reduce the stabilization of the open‐from dye isomers, and thus a faster decay of the irradiated species is observed. Control over the fading speed of photochromic dyes is interesting for applications requiring a particularly fast or slow fading speed.

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“…[19][20][21][22] The spiropyranes encapsulation into a glassy sol-gel matrix is an interesting starting point to prepare specific light sensors. [23][24][25] The main purposes of the present work are: the design, preparation and characterisation of sol-gel glasslike materials sensitive against light radiation in the visible range and, as far as possible, the production of a reversible and reusable device. Such a sensitive material should modulate its optical response inside the light intensity range allowed for the correct conservation of historical objects exposed or stored in museums.…”

Section: Introductionmentioning

confidence: 99%