高電壓低電流之電弧放電法合成單層奈米碳管及其純化與電阻電容測試

Synthesis of single walled carbon nanotubes by high voltage and low current arc discharge: purification, resistance and capacitance measurements of single walled carbon nanotubes

陳昱廷(Yu-Ting Chen)

指導教授 ： 徐文光

國立清華大學/工學院/材料科學工程學系/碩士(2006年)

https://doi.org/10.6843/NTHU.2006.00237

摘要

一般使用電弧放電法合成單壁奈米碳管的電源供應條件大多皆為低電壓、高電流，範圍為20~40伏特、50~100安培，製程反應時間為15~120分鐘，單壁奈米碳管純度約50%，本論文首度嘗試高伏特、低電流，即200伏特、20安培，製程反應時間為1~3分鐘，並且經由比較在不同製程條件下，即不同的氦氣壓、電壓、金屬含量，成功的找出當氦氣壓為100torr、電壓為200伏特、金屬含量為C：Y：Ni＝2.5：0.1953 ：0.5415，能成功的合成出2g的原始煤煙(此時消耗陽極石墨棒長度5cm、直徑1cm) ，其單壁奈米碳管純度約20%，再藉由氧化熱處理與鹽酸處理的純化步驟，能將原本純度約20%的單壁奈米碳管提升到60%以上，最後藉由微小電路量測純化前後的單壁奈米碳管的電性發現，單壁奈米碳管的純度越高，電阻值越低而電容值越高。

關鍵字

單層奈米碳管 ； 電弧放電法 ； 純化

並列摘要

Arc discharge was generally used to synthesize high quality single-walled carbon nanotubes (SWNTs) with low voltage (20 ~ 40 V) and high current (50 ~ 100 A), respectively. Meanwhile, reaction time is controlled to 15 ~ 120 minutes and 50 % total yields is estimated. In our study, it is the first time to produce SWNTs via high voltage (200 V) and low current (20A), and finally, a high efficient condition (100 torr He, 200 V, composition of C：Y：Ni＝2.5：0.1953 ：0.5415 and 3 minutes reaction time) was proposed to synthesize SWNTs. When the anode was consumed 5cm in length and 1cm in diameter, 2g raw soot will be obtained and its purity is about 20%. Heat-oxidized and hydrochloric acid-pickling treatments are used to purify our raw soot and then the yield percentage is rise to more than 60%. Furthermore, compared to pristine SWNTs, purified SWNTs perform a higher capacitance and electrical conductance which are confirmed by a 2 port measurement.

並列關鍵字

single walled carbon nanotubes ； arc discharge ； purification

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