| Summary: | 碩士 === 國立交通大學 === 環境工程系所 === 96 === Ammonia is an odorous gas which commonly exists in the atmosphere due to human, agricultural and industrial activities. And typical online ammonia sensing instruments provide high resolution data but the instrument cost is usually expensive. On the other hand, the low cost ammonia measurement devices such as ammonia sensing probes are limited by their low accuracy of measurement.
In this study, we developed the ammonia sensing material by using MCM-41 impregnated with bromocresol green. MCM-41 is one kind of mesoporous molecular sieves. It can be applied to many fields due to well-defined pore shapes, narrow distribution of pore sizes, large pore volumes, high surface area, excellent thermal, hydrothermal, chemical and mechanical stability. And the bromocresol green dye (BG) is commonly used as a pH indicator with colorimetric from pH 3.8 (yellow) to pH 5.4 (blue).
The results showed that visible color change was observed within 30 sec of ammonia detection from 1~5ppm NH3 concentration level. Besides, the adsorption of ammonia gas was preceded with adsorption efficiency of over 95%. Thus the adsorbents can provide further application potential as a color indicator for an ammonia adsorber upon saturation.
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