金属纳米粉装置设计

摘要

纳米科技是二十世纪八十年代发展起来的一门新兴交叉、前沿学科。在二十一世纪纳米科技是三大重要技术之一，属于前沿性课题之一。其中纳米粉体的制备是纳米科技的重要研究内容之一。蒸发冷凝法制备纳米粉体是一种较早的物理方法，本文用电弧法制备，也是属于蒸发冷凝法的一种。

本文首先介绍了纳米科技的基本知识及其发展状况和应用前景。然后设计了一套电弧加热法制备纳米粉体的实验装置。该装置的工作原理是在一定压力的惰性气氛或反应气氛中，将金属等材料作为电弧的电极，使其在高温电弧等离子的作用下被溶化、蒸发。蒸汽遇到周围的气体就会被冷却或发生反应形成超微粉。该系统共有加热系统、真空系统、生成室、收集室等几部分组成。首先针对纳米颗粒的生产条件设计了生成室和真空系统。然后用电弧加热制备生成纳米蒸汽。冷阱采用了不断输入液氮实现了急速冷却，使蒸汽快速成核以保证纳米尺度。最后通过采用手套箱结构的收集装置实现真空室中粉体的包装从而避免了氧化。整个系统易于加工实现，能够满足制备纳米微粒的实验需求。

关键词：纳米粉体；电弧加热；制备；冷阱

Abstract

Nanotechnology is developing a newcross-cutting, cutting-edge disciplines in the eighties of the twentieth century. Nanotechnology in the twenty-first century technology is one of the three most important are the forefront of one of the topics. Preparation of nano-powder of which is an important research nanotechnology one. Prepared by evaporation condensation nanopowder is a physical method earlier in this paper was prepared by arc, but also belong to a kind of evaporation condensation method.

This article introduces the basic knowledge of nanotechnology and its development and application prospects. Arc and then designed a nano-powders prepared by heating of the experimental apparatus. The working principle of the device is in a certain atmosphere of pressure of inert or reactive atmosphere, such materials as metal arc electrodes, so that at a high temperature arc plasma melting under the role of evaporation. Encountered in the surrounding gas steam will be cooled or the formation of ultrafine reaction. The system total heating system, vacuum system, to generate room, the collection consists of several rooms. First of all, for the production of nanoparticles designed to generate conditions of rooms and vacuum system. Preparation of arc and then use to generate nano-steam heating. Cold trap using liquid nitrogen to achieve a constant input of rapid cooling, so that rapid nucleation of steam to ensure that the nanometer scale. Finally, through the use of glove-box structure of the collection device to achieve a vacuum packed powder chamber to avoid oxidation. The realization of the entire system is easy to process, prepare to meet the experimental needs of nanoparticles.

Key words: nano-powder; arc heating; Preparation; cold trap

目录

第一章绪论 (1)

第1.1节引言 (1)

第1.2节金属纳米粉的制备方法概述 (4)

1.2.1机械法 (4)

1.2.2物理法 (5)

1.2.3化学法 (6)

第1.3节纳米粉体制备及应用国内外现状 (7)

1.3.1纳米粉体制备及应用的国内现状 (7)

1.3.2纳米粉体制备及应用的国外现状 (9)

第1.4节本文研究的主要内容 (11)

第二章电弧法制备金属纳米粉研究 (13)

第2.1节电弧 (13)

2.1.1电弧物理 (13)

2.1.2弧柱中的气体电离 (14)

2.1.3电极的电子发射 (16)

2.1.4电弧的物理特性 (18)

第2.2节电弧的应用 (23)

第2.3节电弧制取金属纳米粉体 (24)

2.3.1电弧法制备金属纳米粉体的原理 (25)

2.3.2金属纳米粉成核机理 (26)

第三章真空系统的设计 (28)

第3.1节实验装置的整体结构设计 (28)

第3.2节真空系统的设计 (29)

3.2.1真空获得设备——真空机组及其选用 (30)

3.2.2真空容器的设计 (33)

3.2.3真空测量系统 (44)

第3.3节真空系统设计中的注意点 (46)

第3.4节真空管路 (48)

第3.5节真空材料 (48)