Preparation Of Oriented Carbon Nanotube Arrays And Their Reflection Properties In Visible - Near Infrared Band

Carbon nanotubes (CNTs) array has unique topology structure and excellent physical and chemical properties, has extensive application value in many fields. At present, the carbon nanotube array as reducing reflection, enhance the absorption of coating materials have great potential application value, and can realize industrial application. But for the reflection properties of carbon nanotube array is still inadequate, the reflectivity results of experiment and theory calculation there is still a certain gap, and reflectivity detailed research on the laws of the change with incident Angle is not enough. In order to systematically study reflection properties of carbon nanotube array, we prepared the directional carbon nanotube arrays with different thickness and the turn Angle in visible, near infrared band of reflective are studied, an extremely low reflectivity is obtained under the small Angle of incidence and the change law of reflectance under different incident angles. The main contents of this paper are presented as follows:(1) In our experement, we used a non-template CVD method with a single-furnace system to prepare vertically aligned nanotube arrays. The reaction temperature, reaction time, catalyst concentration, hydrogen concentration were systematically studied for the influence of the carbon nanotube array tissue morphology, and got the controllable optimization paramerers of the preparation of carbon nanotube:when the growth time was fixed, the length of the aligned carbon nanotube arrays reached its peak in growth temperature 700 ℃, catalyst concentration 0.05 g/ml, hydrogen concentration 2/8; the growth rate of carbon nanotube arrays was divided into two parts, in the first 25 min time the growth rate of carbon nanatubes was basically linear growth, but after 25 min the growth rate of carbon nanatubes got very gently; the suitable aligned for carbon nanotube arrays growth temperature range is 700～740 ℃, catalyst concentration range is 0.05～0.06 g/ml, growth time range is 5-25 min, hydrogen concentration range is 1/9～3.5/6.5.(2) We studied the reflection properties of the carbon nanotube in the visible-near infrared wave band. We found that in the relation curve between the incident angle and reflectivity a very special point of view was observed, under the incidence angles before the special point of view the reflectivity were almost to zero, after that the reflectivity showed a trend of exponential growth with incidence angles; and the special point of view decreased with the increasing wavelehth; carbon nanotube arrays with light poor direction had not too big effect, and in the certain wavelength cases there was no obvious regularity between the the special point of view and thickness, but on the whole length of tubes are lower than those of short carbon nanotubes reflectivity.