26.03.2014 7:39

What good graphene cardboard

If we manage to create a mass production method of such materials, energy storage experimental graphene nanocomposites and get a strong push forward.

Pekka Koskinen ( Pekka Koskinen ) of Yuvyaskyulskogo University (Finland) proposed a new type of nanostructures – graphene “cardboard.” In fact, this graphene sheets stacked in a wavy surface – a kind of corrugated graphene.

That the structure is not deformed, invited both sides to protect its conventional flat sheets of material.

Graphene is a new type of composite composed of undulatory medium and two flat outer layers. (Here and below illustration Pekka Koskinen.)

Recently, it has been experimentally shown that the graphene sheets under certain conditions arise naturally folds such as those that can be observed on the thin fabric. According to the Finnish materialovedov such folds can be fixed by linking the folded sheets together and flat graphene “walls” by covalent bonds introduced into the material by irradiation or chemical functionalization.

Trying to simulate the possible effects of such grafenokartona Mr. Koskinen concluded that depending on the frequency and size of waves all the qualities of the new material, including mechanical, can be significantly modified in a controlled manner.

In particular, increasing the load, bending modifiable graphene sheet can make waves as flat and sinusooboraznymi or even mushroom and flattened. As a result these four “phase” graphene paperboard will have different strength and functionality dissimilar electrodes composed of various types of batteries or capacitor plates. And due to the greater than usual (flat) graphene surface area grafenokarton working in such devices will likely have much higher rates.


Phase diagram of graphene cardboard. Depending on the force applied to the deformable material, waves formed on the surface will have a different shape.

Applying various efforts in the formation of “gofrografena”, you can get the final product with different degrees of flexibility. And the difference between the least and most flexible types of such “nanokartona” will be approximately tenfold, says the researcher. Among other exotic properties of the simulated material stands the possibility of realizing his negative value of Poisson’s ratio . That is, an application of a load material is likely to become thicker in the direction perpendicular to the stress, as if he was the polymer of auksetikov . Materials of this type have special mechanical properties easily absorb large amounts of mechanical energy and effectively resist destruction. Create possessing such qualities of graphene-based nanocomposite would open a new page in a number of practical applications.

Report on a study published in the journal Applied Physics Letters .