Graphene Membraned Blocks Helium and Other Gasses, Allows Water Through

[Drakkith]

Just read this article and figured I'd share it: http://arstechnica.com/science/news...-things-are-just-right-water-flows-freely.ars

However I do have a question. The article never explained why helium, hydrogen, and other gasses were being blocked, they only explained how water was allowed through. Per the article:

To explain how this was possible, the authors hypothesized that the size between the layers of graphene were just right. They suggest that, at a free channel spacing of just about five angstroms, a monolayer of water forms that is capable of undergoing a low-friction flow in the two-dimension channels that exist between the layers (take that, no slip hypothesis!). To move between layers—and hence traverse the membrane—the authors posit that a percolating network of graphene nanocapillaries exists that allows the water to flow throughout and across the membrane.

What about this particular way of assembling the graphite would cause helium and hydrogen to not leak out?

 

[DrClaude]

Link to original paper:
http://dx.doi.org/10.1126/science.1211694