碳纳米管材料的研究现状及发展展望[英文]

Research status and development prospect of carbon nanotubes Abstract:

Carbon nanotubes due to their unique structure and excellent physical and chemical properties, and has wide application prospect and huge commercial value. This paper reviewed the methods for preparing carbon nanotubes, structural properties, application and development trend of carbon nanotubes.

Keywords: carbon nanotubes; preparation; antistatic; stealth; radar absorbing coating

Nanometer material because of its size in the transition region junction of atomic clusters and macroscopic objects, with the quantum size effect, small size effect, surface effect and the macroscopic quantum tunnel effect and other characteristics, exhibit many unique physical and chemical properties. Nanometer material nineteen eighties early after the formation of the concept, the world have paid great attention. It has unique properties, physical, chemical, material research, biology, medicine and other fields with meters of new opportunities.

1, carbon nanotube preparation, structure and properties

1.1, the preparation of carbon nanotubes

1.1. 1 arc method

Graphite arc method is carbon nanotube synthesis method is the most typical of the earliest. The principle of arc chamber filled with inert gas protection, two rod of graphite electrode near, pull up the arc, and then opened, in order to maintain stable arc (1). The relatively high temperature cathode anode discharge process, so the graphite anode is consumed continuously, at the same time deposit containing carbon nanotubes product [2] on graphite cathode. This method has the characteristics of simple and fast, carbon nanotubes can maximize the graphitization, tube less defects. But there are disadvantages are: arc discharge violently, difficult to control the process and product, composition of carbon nanoparticles, amorphous carbon or graphite debris, impurities, so it is difficult to separate. After years of study, researchers have improved on the method, such as Takizawa et al. Discharge by arc, by changing the catalyst of nickel and yttrium ratio, the diameter distribution control product objective. Colbert[3] et al. General cathode (Boulder graphite electrode) into a cooled copper electrode and graphite electrode, in the above, morphology and structure. This product, the arc discharge method have rejuvenated.

1.1.2 catalytic pyrolysis method

Catalytic pyrolysis method, chemical vapor deposition, by hydrocarbons or carbon oxide cracking in catalytic. The basic principle of the organic gas (such as acetylene, ethylene) mixed with a certain proportion of nitrogen as the suppression of gas, prior to removing the oxygen into the quartz tube, at a certain temperature, the formation of carbon on the catalyst surface cracking, carbon source through the catalyst diffusion in the catalyst surface, after long carbon nanotubes, at the same time pushing forward [4] small catalyst particles. Until the catalyst particles are coated with a layer of graphite, carbon nanotube growth end. The advantages of this method are: easy to control the reaction process, simple equipment, low cost of raw materials, large-scale production, higher yield. Disadvantages are: low reaction temperature, carbon nanotube layer number, the degree of graphitization is poor, and there are many crystal defects, mechanical properties and physical and chemical properties of carbon nanotubes may have adverse effects.

1.1.3 ion or laser evaporation method

The 1996 Nobel Prize for chemistry, carbon nanotubes were synthesized to obtain one of the Smally team for the first time using laser evaporation method. Since then, laser evaporation method is an effective method for preparing single-walled carbon nanotubes of [5]. This method in Ar atmosphere, with the double pulsed laser evaporation containing Fe