Modeling Nanotube Applications

Joan Adler, Tali Mutat, Polina Pine, Moshe Sheintuch and Yuval Yaish

Carbon nanotubes have a wide variety of actual and potential applications,
and are small enough that modeling of these applications on a atomistic 
scale is possible, if not easy. Two diverse applications under study at 
the Technion are nanotubes as seperators of diffusing molecules 
(physics/chemical engineering) and nanotubes as mass sensors in NEMS 
(physics/electrical engineering). Both projects use  Molecular Dynamics:
in the former this is combined with Grand Canonical Monte Carlo in 
dual control volumes. We model the nanotube atoms with a Reactive 
Empirical Bond Potential, and use predictor-corrector variants for
the equations of motion in the diffusion project and verlet in the
mass-sensor one.

In the former the nature of the diffusion and of the molecular seperation 
is studied for different loadings and molecular mixtures and in the latter
the thermal vibrations are calculated. In both cases great attention to the
 ``statistical mechanical'' aspects such as equilibration are required. 
In the former an exploration of diffusion behaviour in
rigid versus flexible nantubes was made. In the latter initial 
results in agreement with an analytic calculation of a special case
were found. Vizualization and animation  with our Atomistic Visualization 
package AViz of the dynamics has been carried out  for both  debugging 
and presentation purposes and  these can be viewed at 
http://phycomp.technion.ac.il/~phr76ja/ccp2007

Links to webpages with animations

  • Diffusion in nanotubes - still figure upper left, animation of benzene diffusion in a nanotube.
  • Vibrations of nanotubes, animation of vibrations.
  • How to draw a nanotube
  • How to slice a nanotube - above center

    and for an alternative approach to model nanotubes,

  • How to crochet a nanotube - above right