奈米碳管海棉氣體檢測器的製作與特性研究

The fabrication and characterization of a carbon nanotube sponge vapor sensor

侯鈺玲(YU-Ling Hou)

指導教授 ： 張士欽

國立清華大學/工學院/材料科學工程學系/碩士(2013年)

摘要

奈米碳管海棉以一種創新的方法去製成有機氣體檢測器並加以利用進行研究。奈米碳管海棉以濃硫酸和硝酸加以酸化並將其加入聚乙烯醇水溶液。當將其碳管液放入冰箱中結冰後，在低壓中利用昇華的方式移除冰，然後遺留下來的便為奈米碳管海棉。以兩塊銅片為電極去放在海棉的兩側做為一個有機氣體檢測器。隨著有機氣體的吸附和脫附造成檢測器的電阻改變，並加以記錄。發現以奈米碳管海棉做成的檢測器對於丙酮和乙醇是展現相當高的響應。
為了縮短檢測器的回復時間，是利用電流去加熱碳管海棉檢測器和增加氣體的脫附速率。當一個相當高的電壓是被施加時，電阻可以在五分鐘內回復並縮短回復時間。而且在經過過電加熱之後，對於碳管海棉的結構並沒有太大的改變。另外在相對濕度的測試中，發現飽和最大電阻值和靈敏度是隨著相對濕度的增加呈現線性的增加。

關鍵字

奈米碳管 ； 氣體檢測器

並列摘要

The application of the carbon nanotube sponges made by an innovative process as organic vapor sensors was studied. Carbon nanotubes were made hydrophilic by acid treatment and then dispersed in water with PVA. After frozen, the ice in the frozen solid was removed by sublimation without melting under low pressure. Then, what left is a carbon nanotube sponge. Copper sheet electrodes were attached on the two opposite sides of the sponge to form an organic vapor sensor. The change of electric resistance of the sponge with adsorption and desorption of organic vapors were investigated. It is found that the carbon nanotube sponge sensor exhibiting high and rapid response to acetone and ethanol vapors.
To shorten the recovery time of the sensor, electric current was applied to heat the CNT sensor and so increase the rate of gas desorption. When a relatively high voltage is applied, the resistance can be recovered in 5 minutes and shorten the recovery time. And then no much difference between the spectra measured before and after the test were found. In the relative humidity test, the saturated maximum resistance and the sensitivity increase linearly with increasing relative humidity from 27 % to 85 %.

並列關鍵字

carbon nanotube ； gas sensor

參考文獻

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