An illustration of a graphene sheet at the atomic scale. Photo: iStock
By Amina Khan, LATimes, April 22, 2014 – http://tinyurl.com/kyozvfl
Kids, do not try this at home: scientists have found that they can create high-quality graphene sheets using a kitchen blender and ordinary dishwasher detergent.
The findings, published in the journal Nature Materials, outline a fresh way to create large amounts of this remarkable material – which could speed up the process of putting them into future computers, smart coatings and solar cells.
Graphene is a two-dimensional lattice of hexagons made up of graphite, the most stable form of carbon under standard conditions. The carbon atoms join to create these single-layer, crystalline sheets with extraordinary properties. It's strong but light (which is why it's used in carbon-fibre bicycle frames), conducts both heat and electricity extremely well and is nearly transparent in its purest form.
It's a "wonder material", according to the American Physical Society, "a million times thinner than paper, stronger than diamond, more conductive than copper."
Graphene does occur naturally; the lead in your typical graphite pencil is made up of slippery layers of flat graphene sheets. But making the ultra pure graphene necessary for future applications is very difficult, particularly if you are trying to suspend the graphene flakes in a liquid – which would be useful to develop spray-on smart coatings.
Essentially, researchers have managed to create high-quality graphene in small amounts, or lower-quality graphene in larger amounts, but not large amounts of high-quality material.
"The commercial development of graphene and related two-dimensional materials is at present restrained by the lack of production techniques ready for industrial scale-up," James Tour of Rice University in Houston wrote in a commentary on the study.
A team of scientists led out of Trinity College, Dublin, came up with a way to take graphite powder, dump it in a laboratory blender with a surfactant mixture and create pure sheets of graphene at far larger quantities than previous methods, the scientists said.
In the future, with scaled-up processes, the production rate could easily be hundreds of times higher than many current outfits.
To test exactly how robust their method was, the scientists also tried the method using a Kenwood kitchen blender and dishwashing fluid and the process largely still worked.
"This clearly shows that even very crude mixers can produce well exfoliated graphene," study co-author Jonathan Coleman and colleagues wrote in the paper.
Tour, who was not involved in the paper, called the work "a hands-on guide for chemical and materials engineers practitioners to make assessments of cost and efficacy".
The findings are a significant step towards being able to mass produce high-quality graphene, which could help spur the development of graphene-related technology, the authors said.
"In the next decade, graphene will find commercial applications in many areas from high-frequency electronics to smart coatings," the authors wrote. "Some important classes of applications, such as printed electronics, conductive coatings and composite fillers, will require industrial-scale production of defect-free graphene in a processable form."
Los Angeles Times