The future hydrogen economy requires gas barrier solutions for new challenges, such as the prevention of permeation losses from polymer tank and pipework materials, or the protection of sensitive components against hydrogen corrosion. Gas loss is particularly critical, as hydrogen is an extremely valuable commodity on the one hand but can also act as an indirect greenhouse gas on the other. In addition, the handling of hydrogen raises safety-related issues. The realisation of a hydrogen economy therefore requires highly efficient hydrogen barriers with complex requirement profiles.

For this contribution, hydrogen permeation through uniaxially strained thin SiO_x based gas barrier films, formed at room temperature and ambient pressure on PET foil substrates by UV photochemical conversion (Photoconversion), was investigated using a dedicated measurement system. Hydrogen permeation measurements were conducted as a function of the stack of laminated single SiO_x barrier films, of the sample temperature as well as of the uniaxial mechanical strain applied to the samples. The results demonstrate a significant overall improvement of the hydrogen barrier properties for both single SiO_x barrier films on PET and laminated single SiO_x barrier films on PET. In the case of strained samples, the hydrogen barrier properties deteriorate due to stress-induced crack formation in the barrier films. This deterioration is strongest for strained single SiO_x barrier films but can be substantially reduced by laminating single SiO_x barrier films.