Theoretical calculation on permeation of gas molecules through crystalline poly (p-xylylene) (PPX) films
- First Online:
- Cite this article as:
- Bian, L., Shu, Y., Xu, J. et al. Sci. China Technol. Sci. (2013) 56: 40. doi:10.1007/s11431-012-5068-2
Molecular mechanics (MM) and the gradually reduced size (GRS) techniques were used to construct the crystalline poly-p-xylylene (PPX) films, including PPX N, PPX C and PPX D. The corresponding chain-end area of crystalline PPX films provides enough free volumes for adsorbing and transferring gas molecules. Then, the permeable properties of gases were calculated using Grand Canonical Monte Carlo (GCMC), NVT-Molecular Dynamics (MD) and cluster analysis methods. The calculated diffusion coefficients are in the same order of magnitude over a range of temperatures and pressures. And there is no permeation property of gases in the inner part of the crystalline PPX films.