改質奈米鈦管應用吸附不同有機蒸氣之研究

Sorption of volatile organic compounds on organic substance-modified titanate nanotube

彭宸鋒(Peng,Chen-Fong)

指導教授 ： 趙換平 ； 鄧志浩

中原大學/工學院/生物環境工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500634

摘要

奈米鈦管具有高表面積，因此可被當作吸附劑使用，目前對有機蒸氣之吸附劑以活性碳為主，但活性碳除製作成本較高外，也可能受到水蒸氣影響以致吸附量降低，因此本研究將以有機物質對合成奈米鈦管進行表面改質，將奈米鈦管表面由親水性轉換成疏水性，再以此吸附揮發性有機物，並討論合成材料對有機物之吸附量與吸附機制。
在本研究中，利用水熱合法製成奈米鈦管，再使用十六烷基三甲基溴化銨(HDTMA)與十八烷基三氯矽烷(OTS)對奈米鈦管進行改質，改質後的材料將以SEM、TEM、FTIR、EDX與接觸角檢測其表面性質，並以此吸附劑吸附甲苯、乙苯、正己烷、正庚烷、1,1,2-三氯乙烷與四氯乙烯，改質前後的奈米鈦管被至於實驗設備中，利用氮氣將個別的有機蒸氣混與帶出通過吸附管，再以Thomas equation 方程式計算出各種有機物之吸附量，並比較吸附量與有機物物化性質之相關性。結果顯示所有的吸附劑對有機物吸附量皆呈現甲苯>乙苯>1,1,2-三氯乙烷>四氯乙烯>烷類，除烷類外皆與有機物的揮發速率與分子量大小有關，對於不同種類有機物則吸附劑吸附量大小OTNT＞HTNT
＞TNT，此結果與吸附劑表面疏水性有關，因此可得表面疏水性高的吸附劑確實可獲得較高之吸附量。

關鍵字

水熱合成、奈米鈦管、揮發性有機物、吸附

並列摘要

Titanate nanotubes (TNTs) with the high specific surface area can be used as the adsorbents. Activated carbon is the most common adsorbent to adsorb volatile organic compounds (VOCs). However, it is high cost to produce the activated carbon. The water vapor might affect adsorption of organic vapor on the activated carbon surface.In this study, we use organic substance to modify the surface of TNT, which changes the hydrophilic surface to hydrophobic one. Then, the synthesized adsorbents were applied to adsorb organic vapor. The adsorptive amounts of VOCs and adsorption mechanism were discussed.
The TNT was synthesized through a hydrothermal method. Then, the TNT was modified using octadecyltrichlorosilane (OTS) and hexadecyltrimethylammonium bromide (HDTMA) to produce OTNT and HTNT. The materials were characterized using SEM、TEM、FTIR、EDX and contact angle. The target VOCs included toluene, ethylbenzene, n-hexane, n-heptane, 1,1,2-trichloroethane and tetrachloroethylene. The synthesized TNT, OTNT and HTNT were laid in the pilot. Nitrogen was used to mix and purge organic vapor to pass through adsorption tube. The adsorptive amount of organic compounds and adsorption mechanisms between the adsorbents and adsorbates were discussed.
Results showed that the highest adsorption capacities of VOCs were for all adsorbents is in the decreasing ordertoluene > ethylbenzene >1,1,2-trichloroethane > tetrachloroethylene>alkanes. Except for alkanes, adsorptive amounts of organic compounds were related to their volatilization rates. The adsorptive amounts for all of VOCs adsorbing on the adsorbents indicated the decreasing order OTNT> HTNT > TNT. So we know the mechanism of adsorption of not only concerned with the hydrophilic and hydrobic organics.

並列關鍵字

Hydrothermal method、titanate nanotubes 、volatile organic compounds、sorption

參考文獻

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