twisted nanoribbons

Zipped Graphene Nanotubes

Roll Up Roll Up, in the world of graphene shares there can be no more apt an answer to the problem of investment choice than to invest in two companies and form a merger, or Roll-up. But, before you close all your trades to invest in this new company , I should just say that the roll up news of the week is not one of take over and consolidation but something all together more interesting; the furling of graphene into carbon nanotubes.

Nanoscale materials are notoriously difficult to fabricate, and nanotubes in particular require atom by atom growth. The problem of chirality, or how the tube spirals to produce metallic or semiconducting properties, has been something that has preoccupied the minds of a team from the University of Jyvaskyla, Finland. With graphene having been previously made from the chemical cleaving of nanotubes the Finnish team began to wonder whether the reverse operation would produce nanotubes of a specific type.

Using a quantum molecular dynamic simulation and classical continuum-elasticity modelling, the team, lead by Oleg Kit, fathomed a way for the graphene to be rolled such that the edges would begin to form bonds with each other. The method requires a twisting motion to produce the effect: the calculations show that graphene nanoribbons create a helical zip when twisted, with the carbon atoms of each edge forming the chemical bonded teeth of the zip. By adjusting the strain of the twist the nanotube can be finessed to create tubes of specific chirality and also used to produce interstitial encapsulation of molecules within the tube.

The twisting forms the tubes in much the same way as a twist to a belt eventually results in a tube and the model suggests that the same method could be adopted for the production of tubes with other nanoscale planar objects.


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