Dye Modification of Nanofibrous Silicon Oxide Membranes for Colorimetric HCl and NH3 Sensing |
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Authors: | Jozefien Geltmeyer Gertjan Vancoillie Iline Steyaert Bet Breyne Gabriella Cousins Kathleen Lava Richard Hoogenboom Klaartje De Buysser Karen De Clerck |
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Affiliation: | 1. Fibre and Colouration Technology Research Group, Department of Textiles, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium;2. Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Ghent, Belgium;3. Sol‐gel Centre for Research on Inorganic Powders and Thin Films Synthesis, Department of Inorganic and Physical Chemistry, Faculty of Sciences, Ghent University, Ghent, Belgium |
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Abstract: | 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 NH3 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. |
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Keywords: | HCl sensors nanofibers NH3 sensors pH‐indicator dyes sol‐gel |
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