Pockets In Graphene Layers Allow Viewing of Liquids With an Electron Microscope 32
slew writes "Looking at liquids with a transmission electron microscope to observe things like crystal growth has been difficult to do. This is because liquids need to be confined to a capsule to view them in a TEM (because the electrons are flying at the sample in a chamber near vaccuum pressures where liquids would evaporate or sublimate). Traditional capsules of Silicon Oxide or Silicon Nitride have been fairly opaque. A paper describes a new technique with a 'pocket' created between two graphene layers which can hold liquids for observation by a TEM and the graphene is apparently much more transparent than previous materials allowing a better view of the processes (like crystalization), taking place in the liquid. The BBC has a non-paywalled summary article."
Graphene pockets today... (Score:1, Interesting)
Other work says water diffuses through graphene (Score:5, Interesting)
TFA seems inconsistent with a recent report that graphene is so transparent to water than one can in effect use a graphene barrier to selectively out-diffuse water. (http://biology-forums.com/index.php?topic=18349.0;topicseen) gives a popularized account of the original work that indicates you can concentrate alcohol in alcohol/water solutions by simply putting a graphene film bottlecap on the bottle. Yahoo! for those of us who want to make EverClear from vodka, I guess.
So if this story is talking about using graphene to enable TEM examination of aqueous systems, I don't see why the water doesn't diffuse rapidly out of the graphene bubble boundary, especially given the tiny volumes that would be involved in a TEM specimen.
The graphene water diffusion paper is "Unimpeded Permeation of Water Through Helium-LeakTight Graphene-Based Membranes", paywalled at Science Mag. Really interesting.
Re:Other work says water diffuses through graphene (Score:5, Interesting)
The liquid used in the experiment was a mixture of Pt(acetylacetonate)2, o-dichlorobenzene and oleylamine.
No water was involved, though you are correct that this technique wouldn't be able to be used for aqueous sstems.