Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotube sandwiches could lead to better composite materials

10.05.2006


By stacking layers of ceramic cloth with interlocking nanotubes in between, a team of researchers has created new composites with significantly improved properties compared to traditional materials. The "nanotube sandwiches," which are described in the May 7 online edition of the journal Nature Materials, could find use in a wide array of structural applications.



"Nanotubes are a very versatile material with absolutely fascinating physical properties, all the way from ballistic conduction to really interesting mechanical behavior," says Pulickel Ajayan, the Henry Burlage Professor of Materials Science and Engineering at Rensselaer and a lead author of the paper, along with colleagues at the University of Hawaii at Manoa. Some fundamental issues, however, have kept researchers from realizing the full potential of nanotubes, particularly when combining them with other materials to make composites. The interface between the materials is not as strong as one might expect, Ajayan notes, because it is difficult to disperse nanotubes and to align them in an orderly way.

Ajayan and his colleagues have pioneered a process to help overcome these difficulties, and they are putting it to use in a wide variety of applications. For the current project, the researchers are applying the process to a new area: reinforced composite fabrics made from woven ceramic fibers. These materials have been used for decades in structural applications, but they tend to perform poorly in terms of "through-thickness," or the ability of a material to respond to forces applied perpendicular to the fabric-stacking direction, according to Ajayan.


"We have demonstrated that these through-thickness properties can be improved by adding nanotube Velcro-like structures between the layers," says Mehrdad Ghasemi-Nejhad, professor of mechanical engineering at Hawaii and a lead author of the paper. To make the new materials, the researchers deposit a forest of carbon nanotubes across the surface of a cloth woven from fibers of silicon carbide -- a ceramic compound made from silicon and carbon. The fabric layers are infiltrated with a high-temperature epoxy matrix, and then several layers of cloth are stacked on top of each other to form a three-dimensional composite "sandwich," with interlocking nanotubes acting to fasten the layers together.

"This is a very nice example of how to use nanotubes to solve major existing problems, rather than going all-out to make composites based on nanotubes alone, which has proven to be a very challenging task," Ajayan says. The team has successfully made cloths up to roughly five inches by two inches, and the process is easily scalable to make larger materials, they say.

The researchers ran several experiments to test the new material’s properties, and they found that the interlocking nanotubes provided remarkable improvements in strength and toughness under various loading conditions. The materials performed extremely well in fracture tests, and they demonstrated a five-fold increase in damping -- or the ability to dissipate energy -- over the original ceramic composites without nanotubes included. This suggests that the new composites could be used in many applications where mechanical properties are important, from automobile engines to golf club shafts.

Tests also showed that both the thermal and electrical conductivity of the new composites were significantly improved, which means that they could potentially be employed as sensors to monitor crack propagation in various structures, the researchers note.

The University of Hawaii at Manoa team included Vinod Veedu, a graduate student at the Hawaii Nanotechnology Laboratory; Anyuan Cao, assistant professor of mechanical engineering; and Kougen Ma, associate director of the Intelligent and Composite Materials Laboratory. Several other Rensselaer researchers also participated in the project: Caterina Soldano, a doctoral student in physics, applied physics, and astronomy; Xuesong Li, a doctoral student in materials science and engineering; and Swastik Kar, a postdoctoral researcher in materials science and engineering.

Tiffany Lohwater | EurekAlert!
Further information:
http://www.rpi.edu

More articles from Materials Sciences:

nachricht In borophene, boundaries are no barrier
17.07.2018 | Rice University

nachricht Research finds new molecular structures in boron-based nanoclusters
13.07.2018 | Brown 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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes

17.07.2018 | Life Sciences

Electronic stickers to streamline large-scale 'internet of things'

17.07.2018 | Information Technology

Behavior-influencing policies are critical for mass market success of low carbon vehicles

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>