隨著奈米科技的發展，奈米材料的結構特性與應用，成為目前科技發展研究的重點之ㄧ。奈米碳管的發現對於奈米材料的發展具重大的影響，由於奈米碳管優異的物理與化學特性，因此具有相當大的應用潛力。 合成後的奈米碳管，會含有大量的金屬觸媒顆粒以及碳不純物，影響後續奈米碳管的應用，所以必須先經過純化程序以提高奈米碳管的純度，然而純化程序會對奈米碳管的物理與化學特性造成改變。本研究藉由不同氧化劑與氧化劑濃度對奈米碳管進行純化，探討純化前後對於奈米碳管表面特性的影響。研究結果顯示，純化程序改變奈米碳管表面物理與化學性質，不同氧化劑純化後奈米碳管的純度，以硝酸為最高，鹽酸次之，其次為過氧化氫，由於硝酸純化後奈米碳管的金屬含量明顯降低，純度因而提升。由氮孔隙吸附分析發現，不同氧化劑純化後奈米碳管表面積與微孔體積皆有增加的趨勢，僅9M 硝酸純化後奈米碳管為例外，氧化劑濃度越高，對奈米碳管表面結構破壞也越大。經傅立葉紅外光譜分析發現，未經處理之奈米碳管表面並無官能基存在，純化後奈米碳管表面化學性質改變，並在缺陷處產生羧基、酚基、羰基三種官能基，不同官能基的含量未必隨著氧化劑濃度增加而增加。實驗結果顯示，純化程序對奈米碳管表面特性造成改變，不同氧化劑純化奈米碳管的影響也不同。 The objective of this work is to study the influences of the oxidant and their concentration on the physical and the chemical properties of the purified CNTs. The properties of the raw and the purified CNTs were examined by thermal gravimetric analysis (TGA), Raman spectroscopy, nitrogen adsorption, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and Boehm’s titration. The TGA results showed that HNO3 can effectively remove amorphous carbon and metal particles while HCl and H2O2 have limited removal efficiency. Raman spectra showed that the G/D ratio of the CNTs increased when the CNTs were purified by HNO3, and that decreased when the CNTs were purified by both HCl and H2O2. Generally speaking, HNO3 is the most effective oxidant, followed by HCl, and H2O2 is the least. It was also found that the total surface area and the micropore volume were increased in all oxidation conditions used in this work, except 9 M HNO3. This was because the CNTs were severely damaged by 9M HNO3 and bundled together. Purifications also introduce functional groups on the CNTs, such as carboxylic, lactone, and phenolic groups. However, the amount of introduced functional groups showed no correlation to the concentration of the oxidation agents.
