Stability against photodegradation of a photochromic spirooxazine dye embedded in amino-functionalized sol-gel hybrid coatings
A photochromic spirooxazine derivative, 1-pro- pyl-3,3,5,6-tetramethyl-spiro[indoline-2-30-[quinolino]oxazine], was successfully embedded in sol–gel thin silica films functionalized with different amino groups. The resulting films show high transparency and exhibit a strong blue col- oration upon ir...
| Autores: | , , |
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| Tipo de documento: | artigo |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2012 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/343370 |
| Acesso em linha: | http://hdl.handle.net/10261/343370 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Photochromic hybrid materials Photostability Spirooxazine |
| Resumo: | A photochromic spirooxazine derivative, 1-pro- pyl-3,3,5,6-tetramethyl-spiro[indoline-2-30-[quinolino]oxazine], was successfully embedded in sol–gel thin silica films functionalized with different amino groups. The resulting films show high transparency and exhibit a strong blue col- oration upon irradiation with UV light. The composition of the embedding matrix has an important effect on the photo- stability of the photochromic molecules upon exposure to sunlight, and can therefore be used to design coatings in which the dye molecules have improved durability. In this sense, the incorporation of different amino groups (–PrNH2, –PrNMe2 and –PhNH2) in the ormosil network, results in an enhanced stabilization of the photochromic dye, as compared with unfunctionalized matrices. In matrices modified with aminophenyl groups (–PhNH2), the photostability of the dye has been increased, reaching a factor of 8, due to the for- mation of hydrogen bonds between the amino groups and the OH groups of the pore surface, limiting the availability of these groups to undergo side reactions with the dye during irradiation that lead to its degradation. Increasing the photostability of the photochromic dye is an important issue for the long term usage of photochromic materials in out- doors applications, limited, nowadays, by their low durability when exposed to sunlight. |
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