本研究運用酸化的多壁奈米碳管（MWCNT）來製備新一代的氣體偵測器，並針對醇類以及其混合物去進行氣體偵測分析。多璧奈米碳管首先進行酸化處理，酸化後的碳管溶於水中並與聚乙烯醇水溶液混合形成一個分散均勻的混合溶液，接著將溶液注入預先準備好的鐵氟龍（Teflon）管中，以Freeze-drying的方式製備出碳管海綿。運用奈米碳管海綿製備而成的氣體偵測器可以偵測在飽合蒸氣壓下水與不同的醇類以及其在不同濃度下的混合物。本研究同時探討其氣體吸附的機制，並分析氣體偵測器對不同種類的受測物其響應值與其分子極性和蒸氣壓乘積間的關係。

Novel gas sensors based on functionalized multi-wall carbon nanotubes (MWCNTs) were fabricated and characterized with alcohols and their mixtures. MWCNTs (Multi-walled-carbon-nanotubes) were first functionalized by acid treatment and were then dispersed in PVA solution. The solution was then transferred into Teflon tubes to fabricate CNT foams by freeze-drying. The sensors were capable of distinguishing water and different alcohols at saturated pressure and their mixtures of varying concentrations. The operating mechanisms for the fabricated sensors were proposed, wherein correlations between the sensitivity of the sensor and the product of the molecular polarity and vapor pressure of different vapors were established and experimentally demonstrated.

I. Introduction 1
2-1 Carbon nanotubes (CNTs) 2
2-2 Carbon nanotube foams 2
2-3 Gas sensors 3
III. Experimental 8
3-1 Materials and equipment 8
3-2 Preparation of dispersed CNTs solution 8
3-3 Fabrication of the CNT sponge gas sensors 9
3-4 Sensor characterization 10
IV. Results and discussion 14
4-1 Typical response behavior and reproducibility of the gas sensor 14
4-1-1 Typical response behavior of sensors 14
4-1-2 Reproducibility of sensors 14
4-1-3 Response of sensors to pure one-component solution 15
4-2 Gas sensing factors 17
4-2-1 Saturated vapor pressure (SVP) and polarity of the analyte vapors 17
4-2-2 Geometry of the analyte molecules 19
4-3 Response of sensor to binary mixture 22
4-3-1 Response of sensors to mixture of ethanol and water 22
4-3-2 Response of sensors to mixture of ethanol and methanol 23
V. Conclusions 38
References 39

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