Forget chemicals, catalysts and expensive machinery — a Kansas State University team of physicists has discovered a way to mass-produce graphene with three ingredients: hydrocarbon gas, oxygen and a spark plug.
Their method is simple: Fill a chamber with acetylene or ethylene gas and oxygen. Use a vehicle spark plug to create a contained detonation. Collect the graphene that forms afterward.
Chris Sorensen, Cortelyou-Rust university distinguished professor of physics, is the lead inventor of the recently issued patent, “Process for high-yield production of graphene via detonation of carbon-containing material.” Other Kansas State University researchers involved include Arjun Nepal, postdoctoral researcher and instructor of physics, and Gajendra Prasad Singh, former visiting scientist.
“We have discovered a viable process to make graphene,” Sorensen said. “Our process has many positive properties, from the economic feasibility, the possibility for large-scale production and the lack of nasty chemicals. What might be the best property of all is that the energy required to make a gram of graphene through our process is much less than other processes because all it takes is a single spark.”
Graphene is a single atom-thick sheet of hexagonally coordinated carbon atoms, which makes it the world’s thinnest material. Since graphene was isolated in 2004, scientists have found it has valuable physical and electronic properties with many possible applications, such as more efficient rechargeable batteries or better electronics.
For Sorensen’s research team, the serendipitous path to creating graphene started when they were developing and patenting carbon soot aerosol gels. They created the gels by filling a 17-liter aluminum chamber with acetylene gas and oxygen. Using a spark plug, they created a detonation in the chamber. The soot from the detonation formed aerosol gels that looked like “black angel food cake,” Sorensen said.
But after further analysis, the researchers found that the aerosol gel was more than lookalike dark angel food cake — it was graphene.
“We made graphene by serendipity,” Sorensen said. “We didn’t plan on making graphene. We planned on making the aerosol gel and we got lucky.”
But unlike other methods of creating graphene, Sorensen’s method is simple, efficient, low-cost and scalable for industry.
Other methods of creating graphene involve “cooking” the mineral graphite with chemicals — such as sulfuric acid, sodium nitrate, potassium permanganate or hydrazine — for a long time at precisely prescribed temperatures. Additional methods involve heating hydrocarbons to 1,000 degrees Celsius in the presence of catalysts.
Such methods are energy intensive — and even dangerous — and have low yield, while Sorensen and his team’s method makes larger quantities with minimal energy and no dangerous chemicals.
“The real charm of our experiment is that we can produce graphene in the quantity of grams rather than milligrams,” Nepal said.
Now the research team — including Justin Wright, doctoral student in physics, Camp Hill, Pennsylvania — is working to improve the quality of the graphene and scale the laboratory process to an industrial level. They are upgrading some of the equipment to make it easier to get graphene from the chamber seconds — rather than minutes — after the detonation. Accessing the graphene more quickly could improve the quality of the material, Sorensen said.
The patent was issued to the Kansas State University Research Foundation, a nonprofit corporation responsible for managing technology transfer activities at the university.
Arjun Nepal, Kansas State University postdoctoral researcher and instructor of physics, describes a special process of mass-producing graphene.
Rutgers experts discover easy way to make graphene for flexible and printable electronics, energy storage, and catalysis
Rutgers University engineers have found a simple method for producing high-quality graphene that can be used in next-generation electronic and energy devices: bake the compound in a microwave oven.
The discovery is documented in a study published online today in the journal Science.
“This is a major advance in the graphene field,” said Manish Chhowalla, professor and associate chair in the Department of Materials Science and Engineering in Rutgers’ School of Engineering. “This simple microwave treatment leads to exceptionally high quality graphene with properties approaching those in pristine graphene.”
The discovery was made by post-doctoral associates and undergraduate students in the department, said Chhowalla, who is also the director of the Rutgers Institute for Advanced Materials, Devices and Nanotechnology. Having undergraduates as co-authors of a Science paper is rare but he said “the Rutgers Materials Science and Engineering Department and the School of Engineering at Rutgers cultivate a culture of curiosity driven research in students with fresh ideas who are not afraid to try something new.”
Graphene – 100 times tougher than steel – conducts electricity better than copper and rapidly dissipates heat, making it useful for many applications. Large-scale production of graphene is necessary for applications such as printable electronics, electrodes for batteries and catalysts for fuel cells.
Graphene comes from graphite, a carbon-based material used by generations of students and teachers in the form of pencils. Graphite consists of sheets or layers of graphene.
The easiest way to make large quantities of graphene is to exfoliate graphite into individual graphene sheets by using chemicals. The downside of this approach is that side reactions occur with oxygen – forming graphene oxide that is electrically non-conducting, which makes it less useful for products.
Removing oxygen from graphene oxide to obtain high-quality graphene has been a major challenge over the past two decades for the scientific community working on graphene. Oxygen distorts the pristine atomic structure of graphene and degrades its properties.
Chhowalla and his group members found that baking the exfoliated graphene oxide for just one second in a 1,000-watt microwave oven, like those used in households across America, can eliminate virtually all of the oxygen from graphene oxide.
Graphene, the one-atom-thick carbon sheet material that could revolutionize everything from energy storage to computer chips, can now be made much more easily – at least, that’s what scientists from Northern Illinois University (NIU) are telling us.
While previous production methods have included things like repeatedly splitting graphite crystals with tape, heating silicon carbide to high temperatures, and various other approaches, the latest process simply involves burning pure magnesium in dry ice