Multi walled nanotubes
Multi-walled nanotubes (MWNT) are made out of several rolled layers of graphene. There are two kinds of MWNT designs: 1- The Russian Doll model, which contains several single-walled nanotubes rolled in a form of a concentric cylinder. 2- The Parchment model, where a single sheet of graphite is rolled in around itself, similar to a parchment. The diameter of Multi-walled nanotubes can variate from 0.2nm to 20nm, but in some cases it can exceed the 100nm range.
Nanotubes are highly conductive and are applied in energy storage, automotive parts, and electronic devices, among others.