Measurement and control of cooling/synthesis processes of carbon clusters in an arc reactor

电弧反应器中碳簇冷却/合成过程的测量和控制

基本信息

批准号：
17540467
负责人：
MIENO Tetsu
金额：
$ 2.37万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

1) Passive Mie scattering experimentUnder normal gravity condition, an obstacle plate is set in a reactor, and dispersed light is recorded by a CCD camera. It is found that about 0.5 micrometer size of carbon clusters generate around the arc plasma, and they flow upwards by natural heat convection (v~0.5 m/s). This flow is in good consistent with the result of fluid simulation. The generation place of carbon clusters is around the plasma, where the gas temperature decreases from 8000 K to less than 1200 K.2) Active Mie scattering experimentLaser light is irradiated from bottom side to upper side through center of the arc plasma. 90 degree-scattered laser-light is detected and processed by the pulse-modulation technique and the Lock'in amplification technique. As a result, larger signal is obtained according to the discharge current and the He-gas pressure. Vertical distribution of the scattered intensity changes a little above the arc plasma.3) Production process of single-walled carbon nanotubesA 8-ch cluster-collector is set aside of the arc plasma, and coming carbon particles are collected at the each position. From this measurement, spatial distribution of nanotubes is measured. As a result, nanotubes are almost produced around the periphery of the arc plasma, where the gas temperature sharply decreases.4) Gas flow and production of multi-walled carbon nanotubes by a thermal CVD methodIn a vertically set glass tube, a small steel-ball is set, on which Ni-catalyst-powder is coated. By flowing Ar gas and ethanol gas, and by 800 C of thermal heating, we could make carbon nanotubes. Depending on the flow direction of hydrocarbon gas,nanotube-density is changed.

1）被动米氏散射实验在正常重力条件下，反应器内设置障碍板，用CCD相机记录散射光。发现电弧等离子体周围产生约0.5微米大小的碳簇，并通过自然热对流（v~0.5 m/s）向上流动。该流动与流体模拟结果吻合较好。碳团簇的生成地点在等离子体周围，气体温度从8000K降低到1200K以下。2）主动米氏散射实验激光通过电弧等离子体中心从下侧到上侧照射。 90度散射激光通过脉冲调制技术和锁定放大技术进行检测和处理。结果，根据放电电流和氦气压力获得更大的信号。散射强度的垂直分布在电弧等离子体上方略有变化。3）单壁碳纳米管的生产过程在电弧等离子体旁边设置8通道簇收集器，在每个位置收集到来的碳颗粒。通过该测量，可以测量纳米管的空间分布。结果，纳米管几乎在电弧等离子体的外围产生，其中气体温度急剧下降。 4）气体流动和通过热CVD方法生产多壁碳纳米管在垂直设置的玻璃管中，一个小钢管设置球，球上涂有镍催化剂粉末。通过通入Ar气和乙醇气体，经过800℃的加热，我们可以制造碳纳米管。根据碳氢化合物气体的流动方向，纳米管密度发生变化。