It is a piece of clear tape embedded with a tattoo - like design made from multiple layers
of graphene flakes.
However, they only had
tiny graphene flakes with diameters in the microns available to them, so that edge effects predominated.
The laser burns away everything but the carbon to a depth of 20 microns on the top layer, which becomes a foam - like matrix of
interconnected graphene flakes.
Flagship - affiliated physicists from RWTH Aachen University and Forschungszentrum Jülich have together with colleagues in Japan devised a method for
peeling graphene flakes from a CVD substrate with the help of intermolecular forces.
The catalytic action of individual Ni atoms at the edges of a
growing graphene flake was directly captured by scanning tunneling microscopy imaging at the millisecond time scale, while force field molecular dynamics and density functional theory calculations rationalize the experimental observations.
Bruce Kane at the University of Maryland in College Park sprayed
charged graphene flakes a micron wide into a vacuum chamber.
The researchers made a thin film of graphene oxide by chemically exfoliating graphite
into graphene flakes, which were then mixed with water and concentrated by centrifugation into a thick slurry.
Theoretically, macroscopical three - dimensional graphene assemblies should retain the properties of
nanoscale graphene flakes.
But rather than a flat sheet of hexagonal rings of atoms, the laser left a spongy array of
graphene flakes attached to the polyimide, with high surface area.
Göteborg, Sweden (Scicasts)-- A tiny layer of
graphene flakes becomes a deadly weapon and kills bacteria, stopping infections during procedures such as implant surgery.
Many researchers — including Jonathan Coleman at Trinity College Dublin — have been chasing ways to make large amounts of good -
quality graphene flakes.
Someone fed water with
graphene flakes in it to spiders and then looked at the spider silk that they spun.
The treatment removes ink binders and reduces graphene oxide to graphene — physically stitching together millions of
tiny graphene flakes.
However, as soon as the defects were covered with few layers
of graphene flakes, the distribution of reactive centers became uniform (without localized reactivity centers typical for defect areas).
Individual Ni atoms catalyzing the growth of
a graphene flake along its edges were imaged on the millisecond time scale.
The images show
a graphene flake before (a), two minutes (b), and eight minutes (c), after exposure to a solution of lithium and liquid ammonia (Birch - type reaction).
«Compared to those small molecules used in current hair dyes,
graphene flakes are humongous,» said Huang, who is a member of Northwestern's International Institute of Nanotechnology.
«The laser aligns
the graphene flakes vertically - like little pyramids stacking up.
Thomas Swan's commercial manager, Andy Goodwin, mentions flexible, low - cost electronic displays;
graphene flakes have also been suggested for use in desalination plants and even condoms.
Graphene flakes can have a very large proportion of edge atoms, all of which have a particular chemical reactivity.