Glass based hydrogen barriers

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Glass containers for long term H2 storage, as for mobile electronic devices and off-grid systems, rely on chemically durable glasses of easy workability and low H2 permeability (< 10-20 mol s-1 Pa-1 m-1 @ 200C). The development of such glasses is still difficult due the lack of correlations between basic glass structure parameters and H2 permeation proved by systematic experimental investigations. During the first stage of our project, we could show that H2 permeation is governed by two factors independently: the atomic packing density (ionic porosity) and the topology of the glass network. The applied second stage of the project should therefore focus on the variation of atomic packing density of a given glass network topology by means of chemical strengthening (alkaline exchange), controlled cooling (fictive temperature) and Ar pressure treatments (mixed gas effects). Although promising basic insights into the structural mechanism of H2 permeation in glass, such phenomena have not been addressed so far. The EGA powder method refined during the first project stage allows measuring the required very low H2 permeability data. The results intended herewith offer essential contributions to the development of efficient H2 storage devices or protection barriers and will improve the basic understanding of related structural mechanisms in glasses.