Graphene

Graphene has emerged as one of the most promising nanomaterials because of its unique combination of exceptional properties: it is not only the thinnest but also one of the strongest materials; it conducts heat better than all other materials; it is an excellent conductor of electricity; it is optically transparent, yet so dense that it is impermeable to gases - not even helium, the smallest gas atom, can pass through it.Graphene is the name for a single layer (monolayer) sheet of carbon atoms that are bonded together in a repeating pattern of hexagons. This sheet is only one atom thick. Monolayers of graphene stacked on top of each other form graphite. Since a typical carbon atom has a diameter of about 0.33 nanometers, there are about 3 million layers of graphene in a 1 mm thick sheet of graphite. In scientific terms: The extraordinary characteristics of graphene originate from the 2p orbitals, which form the pi state bands that delocalize over the sheet of carbons that constitute graphene. Harder than diamond yet more elastic than rubber; tougher than steel yet lighter than aluminum.