Graphene Technologies, a company pursuing commercial applications of the carbon nano-material known as graphene, has been issued US Patent Number 8,420,042 for a breakthrough process for atom-by-atom synthesis of graphene by the exothermic chemical reduction of carbon dioxide.
This process represents a dramatic departure from the current methods of producing graphene, such as chemical vapor deposition and chemical exfoliation of graphite.
Graphene consists of a single atomic layer of carbon atoms arranged in a hexagonal lattice structure. Over the past decade it has garnered widespread attention in the scientific community due to its electrical and thermal conductivity, strength, transparency and specific surface area. It can be manufactured in various forms, including nano-scale platelets or film.
By combusting magnesium in the presence of carbon dioxide, Graphene Technologies is able to produce bulk volumes of pristine, few-layer graphene platelets from inexpensive, commonly available feedstock. The reaction uses carbon dioxide to oxidize magnesium at temperatures up to 7,000°F, forming nano-scale magnesium oxide and carbon. Process parameters such as reaction temperature, thermal gradient and pressure can be used to control the morphology of the graphene produced. Additionally, the process can be operated to chemically functionalize or dope the graphene product and to produce nano-forms of other materials added as reactants.
The patent also covers a multi-stage reactor designed to utilize energy produced by the highly exothermic reaction and recycling of the magnesium as feedstock.
"With this process for producing graphene from carbon dioxide, Graphene Technologies is setting a new standard in terms of cost, quality, scalability and sustainability," said Jon Myers , the company's CEO. "Our next challenge, which we are pursuing both independently and jointly with our corporate partners, is to use our production technology as a platform upon which to develop new applications. We are moving quickly on several opportunities and will have more to say soon."