Toroidal Carbon Nanotube as Molecular Motor

In this work we propose a system that avoids the open extremities of external nanotube (NT) using a device with an external nanotube has the form of a closed ring and the internal nanotube (as a probe) in a form as semi-closed nanotube. The system consists of a rigid and static closed ring nanotube and the internal probe allowing relaxation between them (internal and external NT). The probe has asymmetric form and results in a system which presents movement by van der Waals (vdW) interactions. The simulations were made by well-known classical molecular dynamics with standard parameterizations. We calculated thermodynamics properties of these devices as molar specific heat (8.985 kcal/(mol K)) and temporary entropy variation. Properties as probe speed for this system was obtained, molecular motor efficiency versus time. In our calculations this system has 2983 carbon atoms with up to almost 7 ps of simulation. We also propose that the probe when moving (by conservation of angular moment) impels NCR in felt opposite to the probe movement, in similar way to the hamster running in a circular cage. These facts can be useful for the constructions of new molecular machines.