本研究利用化學氣相沉積法(CVD)成長多壁奈米碳管，以乙炔做為碳源、二茂鐵和二甲苯的混合溶液作為催化劑，藉由改變成長溫度、碳源種類、反應時間、催化劑濃度、反應氣體(乙炔)流量以及大氣電漿表面處理等實驗參數，觀察不同的製程參數對奈米碳管成長之影響。使用電子顯微鏡觀察奈米碳管之形態，並以拉曼光譜儀分析奈米碳管的性質。 實驗結果顯示：成長溫度、碳源種類、反應時間、催化劑濃度、反應氣體流量皆會在特定的範圍內，成長出濃密且排列良好的奈米碳管，在反應溫度810oC、反應時間10分鐘、乙炔流量2.5sccm、催化劑濃度10wt%的成長條件下，可成長出長度約130微米之直立奈米碳管。而經過大氣電漿表面處理後之試片，可藉由電漿活化試片表面，提高試片的表面能，增加試片表面的吸附性質，實驗證明適當的電漿表面處理可明顯改善試片表面的吸附能力，使得碳原子和催化劑能有效地沉積在試片表面。 奈米碳管的成長參數是影響奈米碳管的外型、數量、品質和純度的考慮因素，使奈米碳管在未來能朝向高成長速率、大面積與高純度的生長仍是一項需要努力的目標。 Thermal chemical vapor deposition (CVD) was adopted in this research to synthesize multi-wall carbon nanotubes where acetylene and ferrocene-xylene mixture were used as the carbon source and catalyst respectively. Effect of the processing parameters such as growth temperature, carbon source, reaction time, concentration of catalyst, flow rate of reaction gas, and pre-treatment of the substrate on the growth of carbon nanotubes were systematically studied. The morphology and characteristics of the obtained carbon nanotubes were analyzed using SEM and Raman spectroscopy. Results showed that densely packed and well-aligned carbon nanotubes could grow to a length above 150μm in 10 minutes duration under the conditions of 2.5sccm of acetylene, 10wt% of ferrocene-xylene and at a growing temperature of 810oC. The atmospheric plasma was employed to activate silicon substrates and results showed that plasma surface treatment could increase the deposition catalysts on substrate and subsequently improved the CNT growth. It was shown in the study processing parameters had profound effects on the shape, quantity, quality and purity of the obtained carbon nanotubes. Further efforts have to be made if higher growth rate, larger area and better purity carbon nanotubes are to be produced in the future.
