Graphene typically costs $200,000 per ton. Now scientists can make it from scraps.
Graphene is incredibly useful, but very difficult to produce, so far.
A new technology developed at Rice University will turn waste into one of the most valuable materials in existence: graphene. Chemist James Tour and his team have developed a rapid process that can turn large amounts of waste into graphene flakes.
It is something very important. The world throws away 30-40% of all food because it spoils, and plastic waste is a global concern. We have already shown that any solid carbon-based material, including mixed plastic waste and rubber tires, can be converted into graphene.
james tour
The value of graphene is mainly due to its incredible resistance and the wide variety of industrial applications it has. This material is made up of a single layer of carbon atoms linked together by six chemical bonds, creating a latticework that looks like chicken wire.
Graphene can be added to all kinds of materials to improve their strength or make them lightersuch as concrete or metals. It is the most conductive material, so it is very useful to be used as a heat sink, for example, in LEDs or smartphones. It could also be used in battery technology, paints, sensors and many other things: the applications of this material are almost endless.
Despite its great utility, graphene is still not part of our daily lives largely due to its prohibitive cost. Graphene is difficult to produce on a large scaleY”the current commercial price of graphene ranges from $67,000 to $200,000 per tonTour explains.
The new technique, called instant heating by Joule effect, it is much simpler, cheaper and does not depend on any solvents or dangerous chemical additives. In a nutshell, a carbon-based material is exposed to 2,760°C heat for just 10 milliseconds. This breaks all chemical bonds in the input material. All atoms except carbon are converted to gas, which escapes in this proof-of-concept device but could be captured in industrial applications. The carbon, however, reassembles into flakes of graphene.
In addition, this technique produces so-called turbostatic graphene. Other processes produce what is known as AB stacked graphene, in which half of the atoms in one sheet of graphene sit on top of the atoms in another sheet of graphene. This results in a tighter junction between the two sheets, which makes them difficult to separate. Turbostatic graphene does not have this order between the sheets, so it is easier to separate them.
The most obvious use case for what the researchers dubbed “graphene flashis to use these graphene flakes as a component of concrete. “Reinforce concrete with grapheneTour explains,we could use less concrete for construction, and it would cost less to manufacture and transport. Basically, we trap greenhouse gases, like carbon dioxide and methane, that food waste would have emitted in landfills. We convert these carbons into graphene and add this graphene to concrete, reducing the amount of carbon dioxide generated during the manufacture of concrete. It’s a win-win environmental scenario with graphene“.
Concrete is one of the main applications of this material, but there are also many others. As this method and others for producing bulk graphene mature, we can expect to see a future with increasingly stronger, lighter, more advanced and less destructive materials and technologies for the ‘environment.
Going through rice.edu