T0501-3-5 Energy accommodation of gas molecules with free-standing vertically aligned single-walled carbon nanotube arrays

Abstract

The scattering of gas molecules on films of vertically aligned single-walled carbon nanotubes was investigated by molecular beam technique. The free-standing samples were employed for the detailed evaluation of the interaction between the films and gas molecules without the presence of substrates. The scattered molecules are divided to three components: reflected molecules, diffusively transmitted molecules, and directly transmitted molecules. Even for the thickness of 0.1μm, most of the incident molecules are reflected on the topmost of the films, where nanotubes are randomly oriented, and well accommodated to the surface temperature. Transmitted molecules exhibit diffusive (i.e. cosine) scattering distribution except for the direction along the beam axis, where molecules preserve their incident velocities without interaction with nanotubes.