Water/humidity and ammonia sensor, based on a polymer hydrogel matrix containing a fluorescent flavylium compound

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Galindo Rosales, FJ (Author) Other; Lima, JC (Author) Other; Luis, SV (Author) Other; Melo, MJ (Author) Other; Parola, AJ (Author) Other; Pina, F (Author) Other

Journal

Title: Journal of Materials Chemistry

Vol. 15

Pages: 2840-2847

ISSN: 0959-9428

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 40 Citations

Scopus - 47 Citations

Other information

Authenticus ID: P-000-639

DOI: 10.1039/b500512d

Abstract (EN): Flavylium compounds can conveniently be encapsulated in water permeable cross-linked poly(2-hydroxyethyl methacrylate) ( PHEMA) polymer hydrogel matrices. The polymer is also permeable to gases, for example ammonia and hydrogen chloride. The ability of the polymer to concentrate water from the surrounding atmosphere was demonstrated. The absorption and emission spectra of the encapsulated flavylium compounds are very dependent on the pH, and by consequence ammonia ( or hydrogen chloride) can be easily detected. The intensity of the fluorescence emission of the flavylium cation (AH+ species obtained in acidic media) is very dependent on the water content due to the efficient excited state proton transfer involving the AH(+)* excited state and water. The combination of flavylium emission sensitivity to water and ability of the polymer to concentrate water from the surrounding atmosphere, confers this material potential utility as a humidity sensor with high sensitivity.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8