Computational studies of gas-carbon nanotube collision dynamics

Molecular dynamics simulations of collisions between gas particles and carbon nanotubes at elevated temperatures show that low frequency thermal vibrations of the nanotube dominate the scattering dynamics and that particle-tube energy transfer in the tube radial direction is far more efficient than that in the axial direction. The dominant role of the tube's thermal fluctuations reduces the importance of other collision parameters such as collider mass and collider-tube interaction strengths, and xenon, neon, helium and hydrogen particles all have similar collision dynamics and high scattering probabilities. At 1300 K, which is the temperature used in catalytic chemical vapour deposition single-walled nanotube growth, hydrogen molecules scatter from the tube while carbon atoms are efficiently trapped on the tube surface.