Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice engineers make first pure nanotube fibers

10.12.2003


This image shows a liquid crystalline solution of sulfuric acid and SWNTs. The solution contains roughly 5.5 percent SWNTs by volume; acid dispersions have resulted in over an order of magnitude improvement in concentration over all previously documented methods.


Discovery could allow industrial production of cables, sheets of pure carbon nanotubes

Researchers at Rice University have discovered how to create continuous fibers of out of pristine single-walled carbon nanotubes. The process, which is similar to the one used to make Kevlar® on an industrial scale, offers the first real hope of making threads, cables and sheets of pure carbon nanotubes (SWNTs).

The research is available online today from the journal Macromolecules.



Scientists estimate nanotubes are about 100 times stronger than steel at one-sixth the weight. By comparison, Kevlar® -- the fiber used in bulletproof body armor -- is about five times stronger than an equal weight of steel. So far, no large-scale objects have been made of pure nanotubes due to a lack of processing methods that are viable on an industrial scale.

Rice’s team believes they have overcome the major hurdle to industrial production of macroscale SWNT objects -- finding a way to store large amounts of nanotubes in liquid form. By dissolving nanotubes in strong sulfuric acid, a team of chemists and chemical engineers was able to achieve solutions containing up to 10 percent by weight of pure carbon
nanotubes -- more than 10 times the highest concentrations
previously achieved. This new processing route uses no polymeric
additives or detergents, which were used in previous processing
methods and are known to be an obstacle to commercial scalability and final product purity.

"As the concentration increases, the nanotubes first align themselves into spaghetti-like strands and eventually they form tightly packed liquid crystals that can be processed into pure fibers," said researcher Matteo Pasquali, assistant professor of chemical engineering.

Nanotubes are hollow cylinders of pure carbon that are just one atom thick. In addition to being very strong, nanotubes can also be either metals or semi-conductors, which means they could be used to manufacture materials that are both "smart" and ultrastrong. NASA, for example, is researching how nanotubes could be use in aircraft and spacecraft.

Chemically, carbon nanotubes are difficult to work with. They are strongly attracted to one another and tend to stick together in hairball-like clumps. Scientists have developed ways to untangle and sort nanotubes, but storing them after processing is difficult. To date, the medium of choice has been detergent and water solutions that contain less than 1 percent of dispersed nanotubes by volume and are processed by using polymer solutions. Such concentrations are too low to support industrial processes aimed at making large nanotube fibers. Moreover, scientists haven’t found a way to remove all the soap and polymer and convert the nanotubes back into their pure form.

"To produce large objects out of nanotubes, chemical processes must use a liquid that can disperse large concentrations of pristine tubes," said Pasquali. "Based on our findings, we believe superacids can be used to make macroscale fibers and sheets of nanotubes using methods that are quite similar to those in widespread use by the chemical industry."

The research paper is titled "Phase Behavior and Rheology of SWNTs in Superacids." Pasquali’s co-authors include Richard E. Smalley, University Professor, the Gene and Norman Hackerman Professor of Chemistry and professor of physics; Robert H. Hauge, distinguished faculty fellow; W. Wade Adams, director, Center for Nanoscale Science and Technology; W.E. Billups, professor of chemistry; research scientists Carter Kittrell, S. Ramesh, and Rajesh K. Saini; graduate students Virginia A. Davis, Lars M. Ericson, A. Nicholas G. Parra-Vasquez, Hua Fan, and Yuhuang Wang, and undergraduate students Valentin Prieto and Jason A. Longoria.



###
This research was funded by the Office of Naval Research, NASA, the Robert A. Welch Foundation and the Nanoscale Science and Engineering Initiative of the National Science Foundation.

The paper is available online at:
http://pubs3.acs.org/acs/journals/toc.page?incoden=mamobx&indecade=0&involume=0&inissue=0.

Jade Boyd | EurekAlert!
Further information:
http://pubs3.acs.org/acs/journals/toc.page?incoden=mamobx&indecade=0&involume=0&inissue=0
http://chico.rice.edu/

More articles from Materials Sciences:

nachricht Robust and functional – surface finishing by suspension spraying
19.09.2017 | Fraunhofer-Institut für Keramische Technologien und Systeme IKTS

nachricht Graphene and other carbon nanomaterials can replace scarce metals
19.09.2017 | Chalmers University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>