Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Composite fibers with carbon nanotubes offer improved mechanical & electrical properties

29.03.2004


A new class of fibers



Strong and versatile carbon nanotubes are finding new applications in improving conventional polymer-based fibers and films. For example, composite fibers made from single-walled carbon nanotubes (SWNTs) and polyacrylonitrile – a carbon fiber precursor – are stronger, stiffer and shrink less than standard fibers.

Nanotube-reinforced composites could ultimately provide the foundation for a new class of strong and lightweight fibers with properties such as electrical and thermal conductivity unavailable in current textile fibers.


Researchers from the Georgia Institute of Technology, Rice University, Carbon Nanotechnologies, Inc. and the U.S. Air Force have been developing new processes for incorporating nanotubes into fibers and films. The results of that work will be presented March 28 at the 227th national meeting of the American Chemical Society in Anaheim, Calif.

"We are going to have dramatic developments in the textile materials field over the next 10 or 20 years because of nanotechnology, specifically carbon nanotubes," predicted Satish Kumar, a professor in Georgia Tech’s School of Polymer, Textile and Fiber Engineering. "Using carbon nanotubes, we could make textile fibers that would have thermal and electrical conductivity, but with the touch and feel of a typical textile. You could have a shirt in which the electrically-conducting fibers allow cell phone functionality to be built in without using metallic wires or optical fibers."

Thanks to the work of Kumar and researchers at the Air Force Research Laboratory, nanotubes have already found their way into fibers known as Zylon, the strongest polymeric fiber in the world. By incorporating 10 percent nanotubes, research has shown that the strength of this fiber can be increased by 50 percent.

Recently, Kumar’s research team has been collaborating with Richard Smalley, a Rice University professor who received a 1996 Nobel Prize for his work in developing nanotubes, which are of great interest because of their high strength, light weight, electrical conductivity and thermal resistance.

The researchers have developed a technique for producing composite fibers containing varying percentages of carbon nanotubes, up to a maximum of about 10 percent. Produced by Rice University and Carbon Nanotechnologies, Inc., single-walled nanotubes exist in bundles 30 nanometers in diameter containing more than 100 tubes.

To produce composite fibers, the bundles are first dispersed in an organic solvent, acid or water containing surfactants. Polymer materials are then dissolved with the dispersed nanotubes, and fibers produced using standard textile manufacturing techniques and equipment. The resulting composite fibers have the similar touch and feel as standard textile fibers.

Addition of carbon nanotubes to traditional fibers can double their stiffness, reduce shrinkage by 50 percent, raise the temperature at which the material softens by 40 degrees Celsius and improve solvent resistance. Kumar believes these properties will make the composite fibers valuable to the aerospace industry, where the improved strength could reduce the amount of fiber needed for composite structures, cutting weight.

"If you can increase the modulus (stiffness) by a factor of two, in many applications you can also reduce the weight by a factor of two," Kumar noted.

But the greatest impact of carbon nanotubes will be realized only if researchers can learn how to break up the bundles to produce individual nanotubes, a process called exfoliation. If that can be done, the quantity of tubes required to improve the properties of fibers could be reduced from 10 percent to as little as 0.1 percent by weight That could help make use of the tubes – which now cost hundreds of dollars per gram –feasible for commercial products.

Including individual nanotubes in composite fibers could help improve the orientation of the polymer chains they contain, reducing the amount of fiber entanglement and increasing the crystallization rate. That could introduce new properties not currently available in fibers.

"If we can do this, that would conceptually change how fibers are made," Kumar said. "Having a very tough temperature resistant material with a density of less than water seems like a dream today, but we may be able to see that with this new generation of materials."

Beyond breaking up the nanotube bundles, researchers also face a challenge in uniformly dispersing the carbon nanotubes in polymers and properly orienting them.

In addition to aircraft structures, Kumar sees nanotube composite fibers bringing electronic capabilities to garments, perhaps allowing cellular telephone or computing capabilities to be woven in using fibers that have the touch and feel of conventional textiles. But producing conducting fibers would require boosting the nanotube percentage to as much as 20 percent.

To advance these concepts, Kumar hopes to form a "Carbon Nanotube-enabled Materials Consortium" at Georgia Tech to conduct both basic and applied research in areas of interest to industry.

He expects composite fibers based on carbon nanotubes to bring about the most significant changes to the textile industry since synthetic fibers were introduced in the 1930s.

"In 1900, nylon, polyester, polypropylene, Kevlar and other modern fibers did not exist, but life today seems to depend on them," he said. "The rate at which technology is changing is increasing, so much more dramatic changes can be expected in the next 100 years. Every major polymer fiber company in the world is now paying attention to the potential impact of carbon nanotubes."

Papers on the work have appeared in the journals Advanced Materials, Chemistry of Materials, Macromolecules, Nano Letters and Polymer. The work on nanocomposites has been sponsored by the National Science Foundation, Air Force Office of Scientific Research, the Air Force Research Laboratory, the Office of Naval Research, Carbon Nanotechnologies, Inc., and the National Institute of Standards and Technology (NIST).

John Toon | EurekAlert!
Further information:
http://gtresearchnews.gatech.edu/

More articles from Materials Sciences:

nachricht Strange but true: Turning a material upside down can sometimes make it softer
20.10.2017 | Universitat Autonoma de Barcelona

nachricht Metallic nanoparticles will help to determine the percentage of volatile compounds
20.10.2017 | Lomonosov Moscow State 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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>