The diffusion of light gases through polyvinyl butyral: Molecular hydrogen, helium, and neon

The diffusion of molecular hydrogen, helium, and neon through a polyvinyl butyral (PVB) membrane is investigated by Molecular Dynamics (MD) simulations. An understanding of the mechanism of this diffusion is crucial to optimize the industrial conditions for the production of PVB with desired properties. In this work, a comparison of the radial distribution functions of light gases (H-2, He, and Ne) around the alcoholic- and ketonic-oxygens of PVB shows that H-2 interacts more strongly with the membrane than He or Ne. Further, it is found that Ne has a lower self-diffusion coefficient while H-2 has more diffusivity through a model of a PVB membrane. Finally, it was found that the mechanism of diffusion of Ne from a low-temperature hopping changes to a liquid-like mechanism at high temperatures. However, the mechanism of H-2 and He diffusion through the membrane was hopping/liquid like in all studied temperatures. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The diffusion of molecular hydrogen, helium, and neon through a PVB membrane is investigated, with hydrogen showing stronger interaction with the membrane, neon having a lower self-diffusion coefficient, and hydrogen exhibiting higher diffusivity.