Carbon nanotubes (CNT), members of the fullerene structural family, are allotropes of carbon with a nanostructure that can have a length-to-diameter ratio greater than one million. These cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science. They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat.
Nanotubes were first observed in 1991 in the carbon soot of graphite electrodes during an arc discharge experiment that was intended to produce fullerenes. However the first large scale production of carbon nanotubes was made in 1992 by two researchers at NEC's Fundamental Research Laboratory. The method used was the same as in 1991. During this process, the carbon contained in the negative electrode sublimates because of the high temperatures caused by the discharge. Because nanotubes were initially discovered using this technique, it has been the most widely used method of nanotube synthesis. Rigaku Vacuum Rotary Feedthroughs are a critical enabling technology for nanotube production by arc discharge.1