Journal of the American Ceramic Society, Vol.93, No.11, 3752-3756, 2010
Hydrogen Gas Permeation Through Al(2)O(3)-SiO(2) Glasses Containing Metal Ions
We reported in this paper on permeation behaviors of hydrogen gas in alumino-silicate glasses doped with Eu(3+), Nd(3+), and Cu(+) ions. The permeation coefficients determined by monitoring the gas flow rate were similar to 10(-13)-10(-12) mol.(m.s.Pa)(-1) in the temperature range of 300 degrees-600 degrees C, which were two orders of magnitude higher than SiO(2) glass. It was found that when hydrogen gas is loaded, it diffuses in glass, followed by reducing the Eu(3+) and Cu(+) ions and forming hydroxyl bonds. The hydrogen gas permeation was also investigated from the formation of hydroxyl bonds, the values of which were smaller than those determined from the gas permeating test. The precipitated copper metal particles were removed by etching in acid solution, resulting into the increased permeation coefficients. On the other hand, the Eu(3+)-containing glasses exhibited decreased coefficients by heating in hydrogen gas.