  The synthesis of single-wall carbon nanotubes (SWCNTs) of desired diameters
and chiralities is critical to the design of nanoscale electronic devices with
desired properties.1-6 The existing methods are based on self-assembly, 7-16
therefore lacking the control over their diameters and chiralities. The present
work reports a direct route to roll graphene. Specifically, we found that the
electrostatic deposition of graphene yielded: (i) flat graphene layers under
high vacuum (10-7 Torr), (ii) completely scrolled graphene under hydrogen
atmosphere, (iii) partially scrolled graphene under nitrogen atmosphere, and
(iv) no scrolling for helium atmospheres. Our study shows that the application
of the electrostatic field facilitates the rolling of graphene sheets exposed
to appropriate gases and allows the rolling of any size graphene. The technique
proposed here, in conjunction with a technique that produces graphene
nanoribbons (GNRs) of uniform widths, will have significant impact on the
development of carbon nanotube based devices. Furthermore, the present
technique may be applied to obtain tubes/scrolls of other layered materials.
