定向碳纳米管阵列的制备及其在可见—近红外波段反射性质的研究

发布时间：2018-04-20 15:25

  本文选题：碳纳米管 + 定向生长　； 参考：《西北大学》2015年硕士论文

【摘要】：碳纳米管阵列(CNTs array)具有独特的拓扑结构及优异的物理化学性能,在很多领域都有广泛的应用。目前,将碳纳米管阵列作为减小反射、增强吸收的涂层材料方面的应用具有巨大的潜在价值,并且可以很快的实现工业化应用。但对于碳纳米管阵列反射性质方面的研究仍然是不足的,实验得到的反射率结果与理论计算仍然有一定的差距,且反射率随入射角度变化规律的研究不够详细。为了系统地研究碳纳米管阵列的反射性质,我们制备了不同厚度的定向碳纳米管阵列并对其在可见-近红外波段变角度的反射性进行了研究,得到了小角度入射下极低的反射率以及在不同入射角度下的反射率变化规律。本论文的主要工作如下：(1)实验中基于改进的无需预先处理衬底的热CVD法系统地研究了反应温度、氢气比例、催化剂浓度及生长时间四个反应条件对垂直定向碳纳米管阵列组织形貌的影响,实现了高质量定向碳纳米管阵列的可控制备：生长时间一定时,碳管阵列的长度在温度700℃,催化剂浓度0.05g/ml,氢气与氩气浓度之比为2/8时达到顶峰；碳纳米管阵列的生长速率分为两个阶段,前25 min基本是线性增长的,之后变得平缓；适宜碳纳米管定向生长的温度范围是700-740℃,催化剂浓度范围是0.05～0.06 g/ml,生长时间范围是5～25 min,氢气与氩气浓度之比为1/9～3.5/6/5。(2)通过对本实验得到的定向碳纳米管阵列进行可见一近红外波段变角度反射率的测量,系统地研究了波长、入射角度及碳管阵列厚度对反射率的影响,并且实验观察到拐角θ0会随着波长的增加而减小；入射角度在拐角θ0之前其反射率极低,入射角度在拐角θ0之后其反射率呈指数增长；从实验研究中还得到轻微的不定向性不会对反射率有太大的影响,并且在波长一定的情况下,厚度和反射率及拐角θ0之间并无明显规律,,但总体上长的碳管比短的碳管反射率更低。
[Abstract]:CNTs array (CNTs array) has been widely used in many fields due to its unique topological structure and excellent physical and chemical properties. At present, the application of carbon nanotube arrays as a coating material to reduce reflection and enhance absorption has great potential value, and can be applied to industrial applications very quickly. However, the research on the reflection properties of carbon nanotube arrays is still insufficient, the experimental results of reflectivity are still far from the theoretical calculation, and the variation of reflectivity with incident angle is not enough detailed. In order to systematically study the reflective properties of carbon nanotube arrays, we have prepared directional carbon nanotube arrays with different thickness and studied their reflectivity at different angles in the visible and near infrared band. The very low reflectivity and the variation of reflectivity at different incident angles are obtained. The main work of this thesis is as follows: (1) in the experiment, the reaction temperature and hydrogen ratio are systematically studied based on the improved thermal CVD method, which does not need to preprocess the substrate. The effects of catalyst concentration and growth time on the morphology of vertical aligned carbon nanotube arrays were investigated. The controllable fabrication of high quality oriented carbon nanotube arrays was achieved. The length of carbon nanotube arrays was 700 鈩，

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