Energy accommodation of gas molecules with free-standing films of vertically aligned single-walled carbon nanotubes

Abstract

The scattering process of gas molecules on vertically aligned single‐walled carbon nanotubes (VA‐SWNTs) was investigated by the molecular beam technique. To investigate interactions between VA‐SWNT films themselves and helium gas molecules without the presence of substrates, free‐standing films were used. The scattered molecules are divided into three components; reflected molecules, diffusively transmitted molecules, and directly transmitted molecules without interaction with SWNTs. Even with the thin film, most molecules have interacted with the films, which suggests that most molecules have interacted at the randomly oriented layer at the topmost of the films. Because of low accommodation coefficients of helium gas, VA‐SWNTs films are thought to be useful as a surface modification to enhance energy accommodation.