CARBON exhibits a unique ability to form a wide range of structures. In an inert atmosphere it condenses to form hollow, spheroidal fullerenes. Carbon deposited on the hot tip of the cathode of the arc-discharge apparatus used for bulk fullerene synthesis will form nested graphitic tubes and polyhedral particles. Electron irradiation of these nanotubes and polyhedra transforms them into nearly spherical carbon 'onions'. We now report that covaporizing carbon and cobalt in an arc generator leads to the formation of carbon nanotubes which all have very small diameters (about 1.2 nm) and walls only a single atomic layer thick. The tubes form a web-like deposit woven through the fullerene-containing soot, giving it a rubbery texture. The uniformity and single-layer structure of these nanotubes should make it possible to test their properties against theoretical predictions.

Cobalt-catalysed growth of carbon nanotubes with single-atomic-layer walls

Large-scale synthesis of aligned carbon nanotubes was achieved by using a method based on chemical vapor deposition catalyzed by iron nanoparticles embedded in mesoporous silica. Scanning electron microscope images show that the nanotubes are approximately perpendicular to the surface of the silica and form an aligned array of isolated tubes with spacings between the tubes of about 100 nanometers. The tubes are up to about 50 micrometers long and well graphitized. The growth direction of the nanotubes may be controlled by the pores from which the nanotubes grow.

https://science.sciencemag.org/content/sci/274/5293/1701.full.pdf

Large-Scale Synthesis of Aligned Carbon Nanotubes

Catalytic growth of single-walled manotubes by laser vaporization

https://www.andrew.cmu.edu/user/dl0p/laughlin/pdf/PMS.pdf

Amorphous and nanocrystalline materials for applications as soft magnets

SINCE carbon nanotubes1 were first synthesized in macroscopic quantities2, it has become possible to explore their physical and chemical characteristics. There has been much speculation3 about the properties of materials encapsulated within the tubes, but experimental studies of this issue require a reliable means of open-ing and filling the tubes. Various approaches have been developed for opening up4–6 the tube ends and encapsulating material4,6,7, but these work only for a limited range of materials or in low yield. Here we describe a general method that allows carbon nanotubes to be opened at the end and filled with a variety of metal oxides using wet chemical techniques. We anticipate that this method will lead to extensive study of the chemistry and physics of filled nanotubes, which might find applications in catalysis, separation and storage technology and in the development of materials with new magnetic and electrical properties.

A simple chemical method of opening and filling carbon nanotubes

Growth and structure of graphitic tubules and polyhedral particles in arc-discharge

Electron and x-ray-diffraction studies of nanotubes have revealed that the distances between the graphitic sheets are larger by a few percent than those in bulk graphite. The mean value of the interlayer spacings is 0.344\ifmmode\pm\else\textpm\fi{}0.001 nm.

Tadanobu Yoshikawa

Papers

Growth and structure of graphitic tubules and polyhedral particles in arc-discharge

Interlayer spacings in carbon nanotubes.

Carbon nanocapsules encaging metals and carbides

Bamboo-shaped carbon tube filled partially with nickel

Synthesis and electron-beam incision of carbon nanocapsules encaging YC2