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The composite porous glass membrane was prepared by coating on porous alumina tubing by sol-gel method. The porous glass layer of the membrane contains 30 mol% of Zr2. The permeation rate of hydrogen of this membrane is ca. 50 times higher than that of a symmet ric porous glass membrane with a reasonable separa tion factor for H2/N2 mixture and this membrane shows no degradation by heating at 500. This mem brane is also proved to be stable by water vapor ex posuring test at 350 in an autoclave.

In Raman spectra of ZnBr2-KBr-PbBr2 glasses, the dominant bands are observed at about 60cm-1 and 155cm-1 or 174cm-1. The 60cm-1 band was assigned to the mode containing bending vibrations and the 155cm-1 or 174cm-1 band to the symmetric mode containing the stretching vibration between zinc and bridging or non-bridging bromine, respectively. The compositional dependence of the intensity of the 155cm-1 and 174cm-1 bands gives information about both the structural role of PbBr2 and the network structure from the viewpoint of bridging and non-bridging bromines. The introduction of PbBr2 increased the number of non-bridging bromine. This indicates that PbBr2 has the same role of glass modifier as that of KBr. On the other hand, the 155cm-1 band was observed even for a glass of the composition with 20mol% PbBr2, in which the atomic ratio, Br/Zn, is 4. This suggests that there are free bromide ions and/or zinc ions coordinated with more than four bromide ions.