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ID 20586
本文ファイル
著者
Asaeda, Masashi
キーワード
silica membrane
molecular dynamics
gas permeation
micropore
NDC
化学
抄録(英)
The mechanisms involved in pressure driven gas permeation through a micropore on vitreous SiO2 membranes were examined molecular dynamics (MD) simulation. Virtual amorphous SiO2 membranes were prepared by the melt-quench method utilizing modified Born-Mayer-Huggins (BMH) pair potential and Stillinger-Weber (SW) three-body interactions. A dual control plane non-equilibrium MD (DCP-NEMD) technique was employed to simulate gas permeation phenomena under a constant upstream pressure, in which the permeating molecules were modeled as Lennard-Jones particles. The dependencies of the permeance of helium and CO2 molecules on temperature and pore size were examined. For cylindrical pores about 8 and 6 Å in diameter, the calculated temperature dependencies for the permeance of helium molecules were similar to the tendencies predicted by the normal Knudsen permeation mechanism, while in the case of CO2 permeation, a temperature dependency larger than helium and a significant deviation from the Knudsen mechanism were observed. The deviation was more obvious for the smaller 6 Å pore model. A simple gas permeation model that takes the effect of the pore wall potential field into consideration satisfactorily explained the permeation properties of CO2 in the high temperature region. The permeation mechanism was also examined from the viewpoint of the lateral potential and density distribution in a micropore. The values for the potential within micropores, predicted from the observed temperature dependencies of the gas permeation rate and using the simple gas permeation model, were in good agreement with the depth of the potential field resulting from the given potential parameters. The findings also indicate that the density (pressure) difference in a micropore between the pore entrance and exit, which could be enhanced by an attractive pore wall potential, might be the true driving force for permeation, particularly in the high temperature region.
掲載誌名
Journal of Membrane Science
293巻
1-2号
開始ページ
81
終了ページ
93
出版年月日
2007-04-20
出版者
Elsevier B.V.
ISSN
0376-7388
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright (c) 2007 Elsevier B.V.
関連情報URL
部局名
工学研究科