| Researchers from the Institute of Problems of Microelectronics Technology and Extra Pure Materials (Russian Academy of Sciences) have designed and tested a new device for production of a new promising material - nanotubes. The researchers believe that it is exactly the material a transport cable can be produced of to connect the Moon and the Earth. Back at the beginning of the last century, the idea was born to build a transport cable between the Earth and the Moon to deliver goods from our planet to the Moon. Until recently, there has been no material enabling to make this idea a reality. Polymers would not stand cosmic radiation, and the steel cable would have enormous weight. The most durable material as of today - Spectra 1000 - would allow to produce a cable of only 315 kilometers long, as the longer cable is simply unable to bear its own weight. Carbonic nanotubes would very well suit the role of a structural material for such a cable. According to the researchers' estimates, a lightweight cable of required length can be produced from this material, the cable being 50 times stronger than the current most durable materials. The problem is that the researchers have not learned yet to produce high quality nanotubes in large quantities: that is either too expensive or feasible only in the laboratory environment. Therefore, this material is still pretty exotic, its price varying from $60 through $100 per gram. The scientists from Chernogolovka have designed a device that allows to produce pretty large amounts of high quality nanotubes. The device is based on a rather simple scheme: spirit, glycerin or their mixture gets from a specially cooled chamber into the zone of graphite heater bar, where the temperature reaches 1000-2000 degrees C. That results in ultraspeed heating and substance combustion. The products precipitate on a special carbonic glass bell covering the device, or they are removed outside together with vapors and gases, thus allowing to protect the product from various unnecessary impacts. Precipitations of such kind normally contain amorphous carbon, soot and various particles covered by a shell of carbon, as well as carbon fibre and nanotubes. However, in this particular case the researchers came across a surprise: the precipitations obtained in the device turned out to contain only nanotubes and carbon fibre. No other admixtures were found. It means that a laborious procedure is not required for rectification from unnecessary compoments. The fibres are 30-150 nanometers thick, and nanotubes are 20-50 nanometers thick, their length being several micrometers. The growth of nanotubes can be accelerated with the help of catalysts - iron, nickel, cobalt and gold. If the surface where nanotubes are to be precipitated is covered with a thin film of such catalyst in the form of some pattern, then nanotubes will precipitate only upon the pattern, the other parts remaining clean. In principle, such devices may lay the foundation for industrial production of nanotubes. Maybe, a nanotube cable will soon connect the Moon and the Earth. |