Thermal dynamics of few-layer-graphene seals

Being of atomic thickness, graphene is the thinnest imaginable membrane. While graphene's basal plane is highly impermeable at the molecular level, the impermeability is, in practice, compromised by leakage pathways located at the graphene-substrate interface. Here, we provide a kinetic analysis of such interface-mediated leakage by probing gas trapped in graphene-sealed SiO2 cavities versus time and temperature using electron energy loss spectroscopy. The results show that gas leakage exhibits an Arrhenius-type temperature dependency with apparent activation energies between 0.2 and 0.7 eV. Surprisingly, the interface leak rate can be improved by several orders of magnitude by thermal processing, which alters the kinetic parameters of the temperature dependency. The present study thus provides fundamental insight into the leakage mechanism while simultaneously demonstrating thermal processing as a generic approach for tightening graphene-based-seals with applications within chemistry and biology.

Automated summary

Graphene is the thinnest imaginable membrane with high impermeability, but leakage pathways at the graphene-substrate interface compromise its impermeability. This study provides a kinetic analysis of interface-mediated leakage and shows that thermal processing can significantly improve the leak rate.