High-Resolution EM of Colloidal Nanocrystal Growth Using Graphene Liquid Cells

Liquid Nanocrystals In high-resolution transmission electron microscopy, grid materials are used to support solid samples while providing a means for preventing a build-up of static charge. Liquids are difficult to study at the same atomic resolution and require encapsulation to prevent excess sample movement, sample damage, or evaporation. Materials that have been used for liquid cells, like silicon nitride or silicon oxide, need thick layers and have poor electron transmittance at the thicknesses required because they contain high atomic number elements. Yuk et al. (p. 61 ; see the Perspective by Colliex ) show that liquids can be encapsulated in graphene sheets, and through this technique, they studied the formation of platinum nanocrystals with atomic resolution. The crystals could be tracked as they selectively coalesced, modified their shape, and formed surface facets.