Nano World: Composites with nano-graphite

July 24, 2006

Strong, lightweight plastic-like composites made with highly electrically conductive sheets of carbon just one atom thick could find use in electronics and protect aircraft from lightning strikes, experts told UPI's Nano World.

The graphite found in pencils is made of layers just a single carbon atom thick known as graphene. Carbon nanotubes are simply graphene that has been rolled into a cylindrical shape. Investigators worldwide are researching carbon nanotubes for use in electronics because they are capable of conducting electricity at high speed with little energy loss. However, scientists have encountered many challenges when it comes to generating nanotubes with consistent electronic properties and with integrating them into circuitry via processes suitable for mass production. Carbon nanotubes are quite expensive to make as well.

Graphene appears to have many of the electronic properties that make carbon nanotubes so attractive. Ideally, researchers could just take graphite and strip it apart into graphene sheets for use in devices. Graphite, which is sold for just a few dollars a pound with about 1 million metric tons sold annually worldwide, is far less expensive than carbon nanotubes. However, making isolated graphene sheets from graphite is not easy because they like to stick together.

Physical chemist and materials scientist Rod Ruoff at Northwestern University in Evanston, Ill., and his colleagues experimented with electrically insulating graphite oxide, an oxygenated form of graphite. They found a version of graphite oxide chemically modified with organic compounds, when dipped in solvents and treated with ultrasound waves, dispersed into sheets of oxygenated graphene. From there, researchers then found they could fuse these sheets with commercial polymers such as rubbers or polystyrene and strip the oxygen away to make them electrically conductive graphene. The polymers help keep the graphene from sticking together.

The researchers found the electronic properties of their graphene-polystyrene hybrids compare well with the best values reported for nanotube-polymer composites. Moreover, unlike the nanotube-polymer materials, the graphene-polystyrene composites are easy to process using standard industrial processes such as injection molding or hot pressing. Ruoff and his colleagues reported their findings in the July 20 issue of the scientific journal Nature.

"They have shown it's possible to produce graphene from graphite using really industrial scale processes so it can be used even for composites," said physicist Andre Geim at the University of Manchester in England.

These materials could have applications in the transportation as well as the electronics industry, said researcher SonBinh Nguyen, a chemist at Northwestern. For instance, chemical engineer Nicholas Kotov at the University of Michigan at Ann Arbor said these composites might find use in aircraft fuselages, which must combine low weight, high strength and electrical conductivity. "It is quite important to have them conductive to prevent damage from lighting strikes and electromagnetic pulses. The two biggest companies in airplane production, Boeing and Airbus, consider it as one of the most important issues in future design of composite planes," Kotov explained.

The graphene in the composites are basically there as wrinkly sheets. Future research can explore how properties of composites alter by flattening these sheets out, and with higher concentrations of graphene, Ruoff said.

Copyright 2006 by United Press International

Explore further: Turbocharge for lithium batteries

Related Stories

Turbocharge for lithium batteries

June 12, 2018

A team of material researchers from Juelich, Munich, and Prague has succeeded in producing a composite material that is particularly suited for electrodes in lithium batteries. The nanocomposite material might help to significantly ...

Graphene: Singles and the few

November 8, 2010

(PhysOrg.com) -- A timely review analyzing the correlation of synthesis methods and physical properties of single-layer and few-layered graphene flakes.

Liquid method: pure graphene production

May 30, 2010

In a development that could lead to novel carbon composites and touch-screen displays, researchers from Rice University and the Technion-Israel Institute of Technology today unveiled a new method for producing bulk quantities ...

Recommended for you

Atomic-scale ping-pong

June 20, 2018

New experiments by researchers at the National Graphene Institute at the University of Manchester have shed more light on the gas flow through tiny, angstrom-sized channels with atomically flat walls.

Chameleon-inspired nanolaser changes colors

June 20, 2018

As a chameleon shifts its color from turquoise to pink to orange to green, nature's design principles are at play. Complex nano-mechanics are quietly and effortlessly working to camouflage the lizard's skin to match its environment.

Method could help boost large scale production of graphene

June 19, 2018

The measure by which any conductor is judged is how easily, and speedily, electrons can move through it. On this point, graphene is one of the most promising materials for a breathtaking array of applications. However, its ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

NeilFarbstein
not rated yet Feb 01, 2009
Vulvox has begun researching heat exchange materials that transfer heat between hot and cold environments. They show very high heat transfer characteristics in experiments and can be manufactured from materials that can be scaled up and it is possible we can take advantage of economies of scale. They transfer heat much faster than stainless steel and they are much lighter than metallic materials.They will be applied in breakthrough products such as geothermal pumps, solar thermal energy collectors, and industrial heat exchangers with much higher efficiencies. They will be products that will increase industrial efficiency and that will pay for themselves even in a recessionary era. Vulvox has begun experiments on new ways to synthesize graphene paper, one of the strongest materials known to science.
HTTP://VULVOX.TRI...d10.html

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.