Graphene: a perfect nanoballoon

TL;DR

This study uses first-principles density functional theory to analyze helium atom penetration through defective graphene, revealing high energy barriers that preserve graphene's impermeability for small atoms, supporting its use in nanocage applications.

Contribution

It provides a detailed quantum mechanical analysis of helium penetration barriers in defective graphene, highlighting the material's potential for nanomembrane construction.

Findings

Penetration barriers decrease exponentially with defect size.

Graphene remains impermeable to small atoms despite defects.

High energy barriers persist even with large defects.

Abstract

We have performed a first-principles density functional theory investigation of the penetration of helium atoms through a graphene monolayer with defects. The relaxation of the graphene layer caused by the incoming helium atoms does not have a strong influence on the height of the energy barriers for penetration. For defective graphene layers, the penetration barriers decrease exponentially with the size of the defects but they are still sufficiently high that very large defects are needed to make the graphene sheet permeable for small atoms and molecules. This makes graphene a very promising material for the construction of nanocages and nanomembranes.