Single-walled carbon nanotubes (Single-Walled Carbon Nanotubes, SWCNTs) by virtue of the unique structure and special physical and chemical properties, has excellent electrical, mechanical, thermal properties, necessarily determines its physical, chemical, information technology, environment science, materials science, energy technology, life and medical sciences and other fields all have broad application prospects.

1. Hydrogen storage materials:

Recent studies have shown that carbon nanotutes is very suitable for use as a hydrogen storage material. According to the structural characteristics of the single-walled carbon nanotubes, leading to both the liquids and gases which have a significant adsorption of carbon nanotubes using hydrogen in the hydrogen storage is the large surface area, the pore structure of the material showed a physical adsorption or chemisorption properties, storing hydrogen at 77-195K, about 5.0Mpa conditions.

2. Large-capacity supercapacitor

Carbon nanotubes with high crystallinity, good conductivity, large surface area, pore size can be controlled by synthetic processes, surface area of up to 100% utilization, with all the requirements of an ideal supercapacitor electrode material.

Super capacitor energy storage mechanism can be divided according to types of energy storage mechanism with high specific surface area of activated carbon electrode of the capacitor, electric double layer capacitor based on carbon electrode / electrolyte interface charge separation generated; using RuO2 and other precious metal oxide electrode the storage mechanism of the capacitor, is based on the adsorption surface of the capacitor body with the oxide electrode redox reaction produced - Faraday pseudo capacitance. In the same area of the electrode, the Faraday is quasi-capacitor capacitance electric double layer capacitor times, and power characteristics of the electric double layer capacitor instantaneous high-current discharge is better than Faraday capacitors. For the electric double layer capacitor, which is to determine the amount of energy stored by the effective specific surface area of the capacitor electrode plate. Due to SWNTs having the largest surface area and good conductivity, carbon nanotubes prepared by the electrodes, can significantly increase the electrical capacity of the electric double layer capacitor. Preparation of raw materials mixed gas of carbon nanotubes Tsinghua horse Hitoshi, who used catalytic pyrolysis of propylene and hydrogen, and by adding a binder or by means of high temperature and pressure process for preparing carbon nanotubes solid electrodes, using sulfuric acid electrolyte solution as prepared based on these carbon nanotube electrodes of supercapacitors.

3. High-strength composite materials

Since the single-walled carbon nanotubes are the most characteristic one-dimensional materials with a very unique, very perfect microstructure and very large aspect ratio, a growing number of experiments show that single-walled carbon nanotubes have extraordinary mechanical properties become the ultimate form of preparation super-composites. Carbon nanotubes as composite reinforcing materials, first performed on a metal base, such as carbon nanotubes iron / matrix composites, carbon nanotube / matrix composites, carbon nanotube / nickel matrix composites, carbon nanotube / copper-based the results show that the composite materials, although the carbon nanotubes may improve certain properties of the matrix material, but because the carbon nanotubes and the metal compound at a high temperature, tend to congregate at the grain boundaries to form a brittle interface level, both of the Q weakened the combined strength and therefore remains to be further studied in recent years, carbon nanotube composites research focus has shifted to the carbon nanotube polymer composite materials, polymer materials force in improving energy side shoots wins while research has made some progress Wu Xijun group by chemical vapor reaction and vacuum sintering method for preparing a successful carbon nanotube composite WC-Co and WC-Co-VC nano carbide, preliminary results indicate that the composite nano-carbide hardness is up, bending strength and conventional hard alloys are similar, with a carbon nanotube composite nano-carbide nano may become a new way to improve the strength and toughness of cemented carbide.

4. The field emission device

Single-walled carbon nanotubes have excellent field electron emission performance, the performance can be used to produce flat panel display devices replace bulky, heavy weight of the cathode tube technology. Researchers at the University of California proof carbon nanotubes have good stability and resistance to ion bombardment ability, good performance, you can work in a vacuum environment 10-4Pa current density reaches0.4A/ cm3. The array of carbon nanotubes deposited on a display a polymer film made of the work of 200 hours at the working voltage of 200V and current density of up to 10-2A/ cm3. Currently, research in this area is close to the industrialization of Japan has made a prototype of such a color TV technology, the image resolution is now known to other technologies impossible to achieve, they predict the species in 2001 TV market. The single-walled carbon nanotubes in the gold film composed of crystalline array provides up to106A/ cm3 of current density. Compared with the conventional electron gun made of carbon nanotubes and, in the air, not only a stable, easy to produce features, and has a lower operating voltage and a large emission current, for the manufacture of large flat displays. Undoubtedly, monitor the effectiveness and profits will draw carbon nanotubes to millions of households, and soon form a new industry.

5. Electrical, mechanical properties integrated application - carbon nanotube muscle

Robot, fiber converters, prosthetics, sonar and other such devices, the Mirage, by the reaction of a material, direct conversion of electrical energy into mechanical energy is crucial, although ferroelectric and electrostrictive material particularly suitable, but the biggest operational temperature and voltage which can allow high and low energy conversion efficiency, its application is very limited, studies of single-walled carbon nanotubes are expected to solve these problems, Banghman et al found that a single-walled carbon nano stress motor brake pipe pieces produced higher than normal muscle, bigger than the high strain modulus ferroelectrics, and ordinary muscles, this macro brakes are made up of billions of nanoscale actuators, whose actuation without ion doping (embedded), to overcome the brake is reduced by ion doping defects life and efficiency, low operating voltage of only a few volts can produce a large strain of the brake, the ferroelectric is much better than conventional brakes , the author studies predict that the energy conversion efficiency by optimizing brake preparing nanotube sheet obtained, is expected to have higher than any known technology to make artificial muscles from dream into reality.

In addition to these five kinds of applications, single-walled carbon nanotubes are also used in nano-electronic devices, catalysis fiber, film industry, manufactured nanomaterials, very broad application prospects, applied research is currently still in the exploratory stage of carbon nanotubes.