In this article here you can read about Rice University’s graphene foam. Today I will go over the basics of graphene and its material properties. I will explain how its chemical structure creates such high strengths and speak briefly about the article.
Mechanical Properties of Graphene
Graphene itself is just a molecule of carbon like diamond or graphite but with a different crystal structure. It forms a 2-D hexagonal structure with 3 hybrid orbital bonds and 1 pi bond that extends orthogonally to the 2-D plane. This is the source for graphene’s exceptional mechanical properties, at least in two directions. This image should explain why; any force applied orthogonally to the plane of graphene molecules will have a different stress/strain relationship than a force applied in parallel to the plane. Materials that exhibit this property are called anisotropic; their material properties vary by direction.
Overcoming Anisotropic Limitations
As you can see from the graphic in the abstract the multiwalled carbon nanotubes (MWCNTs) and sintered Nickel are used in conjunction to create a template for the graphene shell. Note the different configurations of the 2-D graphene layers; by layering different orientations of graphene planes researchers overcame the anisotropy of the graphene.