Carbon nanotube
Allotropes of carbon with a cylindrical nanostructure / From Wikipedia, the free encyclopedia
Dear Wikiwand AI, let's keep it short by simply answering these key questions:
Can you list the top facts and stats about Carbon nanotube?
Summarize this article for a 10 year old
A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range (nanoscale). They are one of the allotropes of carbon. Two broad classes of carbon nanotubes are recognized:
- Single-walled carbon nanotubes (SWCNTs) have diameters around 0.5–2.0 nanometres, about 100,000 times smaller than the width of a human hair. They can be idealised as cutouts from a two-dimensional graphene sheet rolled up to form a hollow cylinder.[1]
- Multi-walled carbon nanotubes (MWCNTs) consist of nested single-wall carbon nanotubes[1] in a nested, tube-in-tube structure.[2] Double- and triple-walled carbon nanotubes are special cases of MWCNT.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Chiraltube.png/320px-Chiraltube.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Kohlenstoffnanoroehre_Animation.gif/220px-Kohlenstoffnanoroehre_Animation.gif)
Carbon nanotubes can exhibit remarkable properties, such as exceptional tensile strength[3] and thermal conductivity[4][5][6] because of their nanostructure and strength of the bonds between carbon atoms. Some SWCNT structures exhibit high electrical conductivity[7][8] while others are semiconductors.[9][10] In addition, carbon nanotubes can be chemically modified.[11] These properties are expected to be valuable in many areas of technology, such as electronics, optics, composite materials (replacing or complementing carbon fibres), nanotechnology (including nanomedicine[12]), and other applications of materials science.
The predicted properties for SWCNTs were tantalising, but a path to synthesising them was lacking until 1993, when Iijima and Ichihashi at NEC, and Bethune and others at IBM independently discovered that co-vaporising carbon and transition metals such as iron and cobalt could specifically catalyse SWCNT formation.[13][14] These discoveries triggered research that succeeded in greatly increasing the efficiency of the catalytic production technique,[15] and led to an explosion of work to characterise and find applications for SWCNTs.