液相純化多壁奈米碳管及酸處理產生官能基之研究

Functionization of multi-walled carbon nanotubes by solution treatments

蔡濬宇(Chun -Yu Tsai)

指導教授 ： 鄭如茵

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2006年)

摘要

本篇論文使用化學液相純化法，首先使用熱重損失分析儀(TGA)分辨不同管徑的多壁奈米碳管熱穩定性，比較40~60nm管徑和10~30nm管徑，選擇表面積大且熱穩定性較高的40~60nm管徑的多壁奈米碳管做為化學液相純化實驗原料，於RO去離子水超音波振盪分散多壁奈米碳管並於RO去離子水加熱煮沸，過濾乾躁製得初始原料。經由逆流冷凝管的廻流裝置，使用相同濃度的單純酸(30%)，硝酸、鹽酸、硫酸經拉曼光譜(Raman spectroscopy)做定性分析看其純度(無定形碳和主結構為六邊形碳的相對比值)，另外使用不同濃度的硝酸當氧化劑，發現濃度愈高多壁奈米碳管純化後產率愈低，但含氧官能基愈多。而由不同酸的混合體積比來探討其羧基的含量，經電子能譜儀(XPS)和傅利葉轉換光譜儀(FT-IR)分析發現隨著硝酸濃度的增加含氧官能基也相對增加，而混合入不同體比的硫酸和鹽酸其羧基的量也相對提高，並使用能量分散光譜儀(EDS)分析催化劑金屬含量。綜合上述的分析找出適當的多壁奈米碳管化學液相純化法和產生較多含量的含氧官能基製程，增加多壁奈米碳管的化學活性。

關鍵字

多壁奈米碳管 ； 含氧官能基

並列摘要

Multi-walled carbon nanotubes (MWNTs) have C=C double bonds that can be opened to create functionality during purification processes in liquid solutions. Before doing purification, we use a thermal gravimetric analyzer (TGA) to measure thermal instability for two MWNT samples (10-30 and 40-60 nm in diameter). Since MWNTs with diameter 40-60 nm keep their structural integrity at a higher temperature than those with diameter 10-30 nm in the TGA measurement, we choose them as our raw sample. After sonication, filtering and drying, our raw MWNTs are purified in a reflux apparatus using different acid solutions such as nitric acid (HNO3), hydrochloride (HCl) and sulphuric acid (H2SO4) in the same concentration. Such purified MWNTs are characterized by Raman spectroscopy to obtain the fraction of sp2 (the graphitic state) to sp3 (the diamond-like state). Meanwhile, using H2SO4 of different concentrations as an oxidant in the HCl solution and repeating the reflux step, we find that the yield of MWNTs decreases with the concentration of H2SO4, yet resulting in more oxygenic functional groups on MWNTs. These observations are later confirmed by X-ray photoemission spectroscopy and Fourier-transform infrared spectroscopy. Finally, energy dispersive spectroscopy is used to analyze the chemical composition of metal catalysts in all purified MWNTs. Our work demonstrates improved purification as well as increased functionality for MWNTs after solution treatments.

並列關鍵字

multi-walled carbon nanotubes ； oxygenic functional groups

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