Nanotubes, as with many of the topics I write about on this site, was a difficult subject for me to grasp. Everything I know about chemistry can be found in a bartender's guide. The significant role that nanotubes play in the benefits and risks of nanotechnology, made it important that I try at least understand the basics. You know what? It wasn't that hard to understand the concept of a nanotube or buckyball, once I learned what an allotrope was.

Allotropes

Diamonds, the hardest known natural mineral, and the flaky graphite used in pencils are both made of carbon. How is it that they are so different?

Pure carbon occurs as many different allotropes (structures which differ only in the way the atoms are arranged.) Allotropes generally differ in physical properties such as color and hardness.

Diamond and graphite are two allotropes of the element carbon. Buckyballs and nanotubes are two more. This diagram shows how the atoms are arranged for each allotrope.

The discovery in 1985 of buckminsterfullerene (buckyball), opened a new era for the chemistry of carbon and for novel materials. The Japanese Sumi Ijima discovered nanotubes in 1991. The nanotubes synthesized in the laboratory showed remarkable mechanic properties as well as thermal conductivity and resistance to flame.