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Dye Modification of Nanofibrous Silicon Oxide Membranes for Colorimetric HCl and NH 3 Sensing
Author(s) -
Geltmeyer Jozefien,
Vancoillie Gertjan,
Steyaert Iline,
Breyne Bet,
Cousins Gabriella,
Lava Kathleen,
Hoogenboom Richard,
De Buysser Klaartje,
De Clerck Karen
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201602351
Subject(s) - materials science , membrane , electrospinning , covalent bond , aqueous solution , silicon dioxide , chemical engineering , nanofiber , ph indicator , doping , sol gel , usable , nanotechnology , organic chemistry , composite material , polymer , optoelectronics , computer science , chemistry , biochemistry , world wide web , engineering
Colorimetric sensors for monitoring and visual reporting of acidic environments both in water and air are highly valuable in various fields, such as safety and technical textiles. Until now sol‐gel‐based colorimetric sensors are usually nonflexible bulk glass or thin‐film sensors. Large‐area, flexible sensors usable in strong acidic environments are not available. Therefore, in this study organically modified silicon oxide nanofibrous membranes are produced by combining electrospinning and sol‐gel technology. Two pH‐indicator dyes are immobilized in the nanofibrous membranes: methyl yellow via doping, methyl red via both doping, and covalent bonding. This resulted in sensor materials with a fast response time and high sensitivity for pH‐change in water. The covalent bond between dye and the sol‐gel network showed to be essential to obtain a reusable pH‐sensor in aqueous environment. Also a high sensitivity is obtained for sensing of HCl and NH 3 vapors, including a memory function allowing visual read‐out up to 20 min after exposure. These fast and reversible, large‐area flexible nanofibrous colorimetric sensors are highly interesting for use in multiple applications such as protective clothing and equipment. Moreover, the sensitivity to biogenic amines is demonstrated, offering potential for control and monitoring of food quality.