Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


'Amplified' nanotubes may power the future

Rice University lab bulks up raw materials for highly efficient electric grid

Rice University scientists have achieved a pivotal breakthrough in the development of a cable that will make an efficient electric grid of the future possible.

Armchair quantum wire (AQW) will be a weave of metallic nanotubes that can carry electricity with negligible loss over long distances. It will be an ideal replacement for the nation's copper-based grid, which leaks electricity at an estimated 5 percent per 100 miles of transmission, said Rice chemist Andrew R. Barron, author of a paper about the latest step forward published online by the American Chemical Society journal Nano Letters.

A prime technical hurdle in the development of this "miracle cable," Barron said, is the manufacture of massive amounts of metallic single-walled carbon nanotubes, dubbed armchairs for their unique shape. Armchairs are best for carrying current, but can't yet be made alone. They grow in batches with other kinds of nanotubes and have to be separated out, which is a difficult process given that a human hair is 50,000 times larger than a single nanotube.

Barron's lab demonstrated a way to take small batches of individual nanotubes and make them dramatically longer. Ideally, long armchair nanotubes could be cut, re-seeded with catalyst and re-grown indefinitely.

The paper was written by graduate student and first author Alvin Orbaek, undergraduate student Andrew Owens and Barron, the Charles W. Duncan Jr.-Welch Professor of Chemistry and a professor of materials science.

Amplification of nanotubes was seen as a key step toward the practical manufacture of AQW by the late Rice professor, nanotechnology pioneer and Nobel laureate Richard Smalley, who worked closely with Barron and Rice chemist James Tour, the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science, to lay out a path for its development.

Barron charged Orbaek with the task of following through when he joined the lab five years ago. "When I first heard about Rice University, it was because of Rick Smalley and carbon nanotubes," said Orbaek, a native of Ireland. "He had a large global presence with regard to nanotechnology, and that reached me.

"So I was delighted to come here and find I'd be working on nanotube growth that was related to Smalley's work."

Orbaek said he hasn't strayed far from Barron's original direction, which involved chemically attaching an iron/cobalt catalyst to the ends of nanotubes and then fine-tuning the temperature and environment in which amplification could occur.

"My group, with Smalley and Tour's group, demonstrated you could do this -- but in the first demonstration, we got only one tube to grow out of hundreds or thousands," Barron said. Subsequent experiments raised the yield, but tube growth was minimal. In other attempts, the catalyst would literally eat -- or "etch" -- the nanotubes, he said.

Refining the process has taken years, but the payoff is clear because up to 90 percent of the nanotubes in a batch can now be amplified to significant lengths, Barron said. The latest experiments focused on single-walled carbon nanotubes of various chiralities, but the researchers feel the results would be as great, and probably even better, with a batch of pristine armchairs.

The key was finding the right balance of temperatures, pressures, reaction times and catalyst ratios to promote growth and retard etching, Barron said. While initial growth took place at 1,000 degrees Celsius, the researchers found the amplification step required lowering the temperature by 200 degrees, in addition to adjusting the chemistry to maximize the yield.

"What we're getting to is that sweet spot where most of the nanotubes grow and none of them etch," Barron said.

Wade Adams, director of Rice's Richard E. Smalley Institute for Nanoscale Science and Technology and principal investigator on the AQW project, compared the technique to making sourdough bread. "You make a little batch of pure metallics and then amplify that tremendously to make a large amount. This is an important increment in developing the science to make AQW.

Adams noted eight Rice professors and dozens of their students are working on aspects of AQW. "We know how to spin nanotubes into fibers, and their properties are improving rapidly too," he said. "All this now has to come together in a grand program to turn quantum wires into a product that will carry vast amounts of electricity around the world."

Barron and his team are continuing to fine-tune their process and hope that by summer's end they can begin amplifying armchair nanotubes with the goal of making large quantities of pure metallics. "We're always learning more about the mechanisms by which nanotubes grow," said Orbaek, who sees the end game as the development of a single furnace to grow nanotubes from scratch, cap them with new catalyst, amplify them and put out a steady stream of fiber for cables.

"What we've done is a baby step," he said. "But it verifies that, in the big picture, armchair quantum wire is technically feasible."

Orbaek said he is thrilled to play a role in achieving amplification, which Smalley recognized as necessary to his dream of an efficient energy grid that would catalyze solutions to many of the world's problems.

"I'd love to meet him now to say, 'Hey, man, you were right,'" he said.

The Robert A. Welch Foundation and the Air Force Office of Scientific Research funded the research. The Air Force Research Laboratory is primary funding agency for the AQW project.

Read the abstract at

Download high-resolution images here:
These images show a single carbon nanotube before and after amplification, a process developed at Rice University seen as key in the development of armchair quantum wire. Such a wire would transmit electricity over great distances with virtually no loss.

(Credit: Barron Lab/Rice University)


Rice University graduate student Alvin Orbaek, left, and Professor Andrew Barron developed a method to extend the length of carbon nanotubes.

(Credit: Jeff Fitlow/Rice University)

Located on a 285-acre forested campus in Houston, Texas, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is known for its "unconventional wisdom." With 3,485 undergraduates and 2,275 graduate students, Rice's undergraduate student-to-faculty ratio is less than 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 4 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to

David Ruth | EurekAlert!
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>