Incorporation and optical behaviour of 4-dimethylaminazobenzene in sol-gel silica thin coatings
Various percentages of 4-dimethylaminazobenzene (dimethyl yellow, DY) have been incorporated into silica sol-gel coatings prepared from tetraethylorthosilicate and methyltriethoxysilane. The dye was entraped in the sol-gel layer maintaining its acid-basic properties. Sensitivity of coatings against...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/417895 |
| Acceso en línea: | http://hdl.handle.net/10261/417895 |
| Access Level: | acceso abierto |
| Palabra clave: | Coatings Dyes Sensors SiO2 Sol-gel processes |
| Sumario: | Various percentages of 4-dimethylaminazobenzene (dimethyl yellow, DY) have been incorporated into silica sol-gel coatings prepared from tetraethylorthosilicate and methyltriethoxysilane. The dye was entraped in the sol-gel layer maintaining its acid-basic properties. Sensitivity of coatings against pH in aqueous media was evaluated by absorption spectrophotometry for each type of samples, including one pre-treated at low temperature. The response time of coatings from acid pH to neutral conditions and vice versa allows to propose the use of this system as a pH optical sensor. On the other hand, several tests oriented to point out the behaviour of coatings during chemical attack were performed: firstly by dipping the samples in distilled water for different lengths of time and, secondly, submitting them to reiterated cycles at 60 °C in a washing machine using conventional abrasive detergent. Results obtained in both cases indicated good resistance, especially for those hybrid films prepared from tetraethylorthosilicate and methyltriethoxysilane doped with 5 wt.% DY. |
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