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Experimental studies of gas permeation through microporous silica membranes
Author(s) -
Yoshioka Tomohisa,
Nakanishi Eisuke,
Tsuru Toshinori,
Asaeda Masashi
Publication year - 2001
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690470916
Subject(s) - permeation , microporous material , permeance , membrane , chemistry , chemical engineering , molecule , chromatography , materials science , organic chemistry , biochemistry , engineering
Permeation mechanism of inorganic gases was studied experimentally and theoretically through microporous silica membranes prepared by the sol–gel method. Inorganic gas permeation was measured using the membranes with subnano pores in diameter. The permeance of He increased with increasing temperature for various cases, while that of CO 2 , O 2 and N 2 decreased. In particular, the observed temperature dependency of CO 2 was greater than those of other gases. In such small pores, the interaction energy between a permeant molecule and the pore wall can affect gas‐permeation properties. A simple gas‐permeation model is used considering the effect of the attractive or repulsive pore‐wall potential field, which deviates from the ambient gas phase of the gas molecule concentration (pressure) in a pore. The model can explain the experimental gas‐permeation properties successfully. Potential curves of CO 2 and N 2 in a silica pore were also calculated to predict the permeation ratio of CO 2 /N 2 . This model can help understand further the gas‐permeation mechanism in micropores.