Positronium lifetimes and gas permeation in Aquivion? for fuel cells

摘要

Variations of ortho-positronium (o-Ps) lifetime and gas permeability of the Aquivion? E8705 membrane were studied as functions of temperature under vacuum and relative humidity at room temperature. When the temperature was varied between 0 and 100 °C in vacuum, the hole volume of Aquivion? E8705, deduced from o-Ps lifetime, gradually increased. However, when the relative humidity was changed at room temperature, the hole volume was essentially unchanged. Good linear correlations between the logarithm of permeabilities of O_2 and H_2 and reciprocal hole volume at different temperatures indicates the importance role of free volume in gas permeation in dry Aquivion? E8705. However, for hydrated Aquivion? E8705 the permeability less depends on hole volume.