Press releases
Please quote Nature Nanotechnology as the source of these items.
The January 2008 issue of Nature Nanotechnology is available online.
January 2008
An amicable separation
Graphene — a carbon–based nanomaterial known for its unique electronic, thermal and mechanical properties — can form stable dispersions in water without the need for additional chemical stabilizers. The research, to be published online this week in Nature Nanotechnology, has practical implications for the development of coatings to reduce static build-up on materials.
Graphene is the name given to the individual sheets of carbon, just one atom thick, that stack together to form graphite. Keeping graphene sheets separate from one another is a difficult task because they tend to stick together, forming larger structures that are not particularly useful. Now, however, using a sequence of chemical reactions, a team led by Gordon Wallace and Dan Li have shown how aqueous dispersions of well–separated graphene sheets can be made from graphite — an abundant and inexpensive starting material.
Rather than relying on either polymer or surfactant stabilizers, their approach maximizes the electrostatic charge on the graphene sheets, ensuring that they repel one another instead of clumping together. This low–cost approach offers the potential for large–scale production of stable graphene colloids that can be processed using well–established solution–based techniques — such as filtration or spraying — to make conductive films. In addition to antistatic coatings, these materials are expected to have applications in flexible transparent electronics, high–performance composites and nanomedicine.
Processable aqueous dispersions of graphene nanosheets
Dan Li, Marc B. Müller, Scott Gilje, Richard B. Kaner & Gordon G. Wallace
Published online: 27 January 2008 | doi 10.1038/nnano.2007.451
