Abstract
The scattering process of gas molecules on vertically aligned single-walled carbon nanotubes (VA-SWNTs) was evaluated by 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 incident molecules were reflected from the films. This result suggests that most molecules well interact with the randomly oriented layer at the topmost of the films. High accommodation coefficients for helium in spite of its mass mismatching to surface atoms, demonstrates that VA-SWNTs films are useful as a surface modification to enhance energy accommodation.
