Anomalous Diffusion of Helium and Neon in Low-Density Silica Glass

Sergey V Kukhtetskiy; Elena V Fomenko; Alexander G Anshits

doi:10.3390/membranes13090754

Anomalous Diffusion of Helium and Neon in Low-Density Silica Glass

Membranes (Basel). 2023 Aug 24;13(9):754. doi: 10.3390/membranes13090754.

Authors

Sergey V Kukhtetskiy¹, Elena V Fomenko¹, Alexander G Anshits^{1

2}

Affiliations

¹ Federal Research Center "Krasnoyarsk Science Center SB RAS", Institute of Chemistry and Chemical Technology SB RAS, Akademgorodok 50/24, Krasnoyarsk 660036, Russia.
² Department of Chemistry, Siberian Federal University, Svobodnyi pr. 79, Krasnoyarsk 660041, Russia.

Abstract

The diffusion properties of low-density non-porous silica glasses (expanded silica glasses) were researched with the aim of searching for the molecular structure of membrane materials intended for the effective separation of helium-neon gas mixtures. It has been shown on a large number (84) of computer models of such glasses that there are molecular structures of silica in which various helium and neon diffusion mechanisms are simultaneously implemented: superdiffusion for helium and subdiffusion for neon. This makes it possible to significantly (by 3-5 orders of magnitude) increase the helium permeability of such glasses at room temperature and maintain a high selectivity for the separation of helium and neon (at the level of 104-105) at the same time.

Keywords: expanded silica glass; helium; low-density silica glass; membrane separation of a helium–neon mixture; neon; permeability; selectivity.

Grants and funding

This research was funded by the budget project FWES 2021-0013 for Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences.