Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Researchers develop simple, cheap way to mass-produce graphene nanosheets

Abstract:
Mixing a little dry ice and a simple industrial process cheaply mass-produces high-quality graphene nanosheets, researchers in South Korea and Case Western Reserve University report.

Researchers develop simple, cheap way to mass-produce graphene nanosheets

Cleveland, OH | Posted on April 18th, 2012

Graphene, which is made from graphite—the same stuff as "lead" in pencils—has been hailed as the most important synthetic material in a century. Sheets conduct electricity better than copper, heat better than any material known, and are harder than diamonds yet stretch.

Scientists worldwide speculate graphene will revolutionize computing, electronics and medicine, but the inability to mass-produce sheets has blocked widespread use.

A description of the new research was published in the online Early Edition of the Proceedings of the National Academy of Sciences.

Jong-Beom Baek, professor and director of the Interdisciplinary School of Green Energy/Advanced Materials & Devices, Ulsan National Institute of Science and Technology, Ulsan, South Korea, led the effort.

"We have developed a low-cost, easier way to mass produce better graphene sheets than the current, widely used method of acid oxidation, which requires the tedious application of toxic chemicals," said Liming Dai, a Kent Hale Smith professor of macromolecular science and engineering at Case Western Reserve and a co-author of the paper.

Here's how:

Researchers placed graphite and frozen carbon dioxide in a ball miller, which is a canister filled with stainless steel balls. The canister was turned for two days and the mechanical force produced flakes of graphite with edges essentially opened up to chemical interaction by carboxylic acid formed during the milling.

The carboxylated edges make the graphite soluble in a class of solvents called protic solvents, which include water and methanol, and another class called polar aprotic solvents, which includes dimethyl sulfoxide.

Once dispersed in a solvent, the flakes separate into graphene nanosheets of five or fewer layers.

To test whether the material would work in direct formation of molded objects for electronic applications, samples were compressed into pellets. In a comparison, these pellets were 688 times better at conducting electricity than pellets yielded from the acid oxidation of graphite.

After heating the pellets at 900 degrees Celsius for two hours, the edges of the ball-mill-derived sheets were decarboxylated—that is, the edges of the nanosheets became linked with strong hydrogen bonding to neighboring sheets, remaining cohesive. The compressed acid-oxidation pellet shattered during heating.

To form large-area graphene nanosheet films, a solution of solvent and the edge-carboxylated graphene nanosheets was cast on silicon wafers 3.5 centimeters by 5 centimeters, and heated to 900 degrees Celsius. Again, the heat decarboxylated the edges, which then bonded with edges of neighboring pieces. The researchers say this process is limited only by the size of the wafer. The electrical conductivity of the resultant large-area films, even at a high optical transmittance, was still much higher than that of their counterparts from the acid oxidation.

By using ammonia or sulfur trioxide as substitutes for dry ice and by using different solvents, "you can customize the edges for different applications," Baek said. "You can customize for electronics, supercapacitors, metal-free catalysts to replace platinum in fuel cells. You can customize the edges to assemble in two-dimensional and three-dimensional structures."

US-Korea NBIT, World Class University and Basic Research Laboratory programs through the National Research Foundation of Korea and the U.S, Air Force Office of Scientific Research funded the research.

####

For more information, please click here

Copyright © Case Western Reserve University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

NanoTechnology for Defense (NT4D) October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Graphene

Nitrogen Doped Graphene Characterized by Iranian, Russian, German Scientists October 21st, 2014

Graphenea opens US branch October 16th, 2014

Charged graphene gives DNA a stage to perform molecular gymnastics October 9th, 2014

Unconventional photoconduction in an atomically thin semiconductor: New mechanism of photoconduction could lead to next-generation excitonic devices October 9th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Discoveries

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Announcements

NanoTechnology for Defense (NT4D) October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Military

NanoTechnology for Defense (NT4D) October 22nd, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

1980s aircraft helps quantum technology take flight October 20th, 2014

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE