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 New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Extensive Funding for Research on Chromatin, Adrenal Gland, and Cancer Therapy

28.06.2017 | Awards Funding

Predicting eruptions using satellites and math

28.06.2017 | Earth Sciences

Extremely fine measurements of motion in orbiting supermassive black holes

28.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>