Carbon NanotubesCarbon nanotubes are one-dimensional carbon material. They were discovered about 10 years ago. A new molecular form of carbon discovered a whole series of new and unexpected physical, mechanical and chemical properties. These unique properties make nanotubes a key element in nanotechnology.Carbon nanotubes are cylindrical elongated structures with a diameter of one to several tens of nanometers and can up to several centimeters long. They consist of one or more hexagonal graphite planes rolled in a tube and usually have a hemispherical head at the end.According to the definition, the basic classification of nanotubes is carried out by the method of folding the graphite plane. This folding method is determined by two numbers n and m, which define the folding direction expansion to the translation vectors of the graphite lattice. This is illustrated in the picture.According to the value of parameters (n, m) two types of the following types of nanotubes are distinguishes:- direct (achiral) nanotubes--- "armchair" or "spike-tooth" (armchair) n=m--- zigzag like (zigzag) m=0 or n=0- helical (chiral) nanotubesOne of the remarkable properties of carbon nanotubes is that their properties depend on geometry. Their electric properties, in particular, depend on angle of torque: carbon nanotubes can have metallic and semiconducting conductivity. Metallic nanotubes conduct electricity at absolute zero temperature, while the conductivity of semiconducting tubes is zero at absolute zero and increases with increasing temperature.Nanotubes can be used in the following areas:Mechanical applications: heavy-duty fibers, composite materials, nanosaclesApplications in microelectronics: transistors, nanowires, transparent conductive surfaces, fuel cellsTo create connections between biological neurons and electronic devices in the latest neuro-computer developments Capillary applications: capsules for active molecules, metals and gases storageOptical applications: displays, LEDsMedicine (in active development)
