可定量化偵測氨氣之顯色材料研究

Abstract

隨著科技的進展，在工業製程、作業環境安全、環境保護等方面都面臨氨氣污染的問題，可知氨氣的去除及偵測相關研究日益重要。本研究利用鋁改質之中孔洞分子篩MCM-41與溴甲酚綠染劑，合成氨氣顯色感知材料。在接觸氨氣時，會產生肉眼可辨識之反應，顏色由黃褐色轉變為藍色。在低濃度氨氣環境中，本材料反應相當靈敏，利用改良的UV-Vis即時偵測光譜儀研究顯示，僅需5分鐘，便可偵測ppmv甚至sub-ppmv的氨氣濃度，在0.25~2ppmv氨氣濃度範圍其檢量線之線性關係相當高(R > 0.998)，理論偵測極限為0.185ppmv；此外，本研究也發現相對溼度可幫助感知材料的變色反應，且填充不同樣品重量可改變其適用偵測範圍；在高溫脫附後，本材料經數十次反覆使用測試，證實其擁有重複使用之特性，為一表現性優異之氨氣顯色感知材料。本研究第二部分則是研發可重複使用之檢知管材料，使用中孔洞材料如SBA、MCM-41與Al-MCM-41為載體，與溴甲酚綠染劑結合，合成氨氣顯色感知材料。探討流量、相對溼度的影響，以及適用濃度範圍，以開發為低成本，可重複使用之氨氣檢知管感測材料，期待能應用於各式工業用途。

A color change mesoporous adsorbent for sensing ammonia gas was developed. Meso-structured MCM-41 impregnated with bromocresol green (BG) dye was prepared as an ammonia sensing material. It was then incorporated into a UV-Vis DRA spectroscopic instrument for online detection of ammonia gas. The results showed that the absorption response of the sensing material was very sensitive upon exposure to ammonia gas, and high linear correlation in the absorbance was achieved with the ammonia test range from 0.25 to 2 ppmv with response time of only 5 minutes. The method of detection limit is 0.185ppmv. Moreover, the effects of relative humidity and sample weight were studied in the UV-Vis DRA system. The color change process was fully reversible during tens of cyclic tests upon repeated adsorption-desorption of the ammonia gas. Such features enable the mesoporous materials to be very promising for optical sensing applications. Furthermore, we applied different mesoporous materials, such as SBA and MCM-41, impregnated with bromocresol green (BG) dye to the ammonia sensing materials. And compare the differences between materials to be applied as the detecter tube.