Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanomaterials Show Unexpected Strength Under Stress

NIST researchers have shown that substances such as silica that are brittle in bulk exhibit ductile behavior at the nanoscale. Computer simulations demonstrate the material extension and necking that occurs during the separation of amorphous (top) and crystalline (bottom) silica nanoparticles.

Credit: NIST
NIST researchers have shown that substances such as silica that are brittle in bulk exhibit ductile behavior at the nanoscale. Computer simulations demonstrate the material extension and necking that occurs during the separation of amorphous (top) and crystalline (bottom) silica nanoparticles.

Credit: NIST

Abstract:
In yet another twist on the strangeness of the nanoworld, researchers at the National Institute of Standards and Technology (NIST) and the University of Maryland-College Park have discovered that materials such as silica that are quite brittle in bulk form behave as ductile as gold at the nanoscale. Their results may affect the design of future nanomachines.

Nanomaterials Show Unexpected Strength Under Stress

GAITHERSBURG, MD | Posted on March 12th, 2008

NIST scientists Pradeep Namboodiri and Doo-In Kim and colleagues first demonstrated* the latest incongruity between the macro and micro worlds this past fall with direct experimental evidence for nanoscale ductility. In a new paper** presented today at the March Meeting of the American Physical Society, NIST researchers Takumi Hawa and Michael Zachariah and guest researcher Brian Henz shared the insights they gained into the phenomenon through their computer simulations of nanoparticle aggregates.

At the macroscale, the point at which a material will fail or break depends on its ability to maintain its shape when stressed. The atoms of ductile substances are able to shuffle around and remain cohesive for much longer than their brittle cousins, which contain faint structural flaws that act as failure points under stress.

At the nanoscale, these structural flaws do not exist, and hence the materials are nearly "perfect." In addition, these objects are so small that most of the atoms that comprise them reside on the surface. According to Namboodiri and Kim, the properties of the surface atoms, which are more mobile because they are not bounded on all sides, dominate at the nanoscale. This dominance gives an otherwise brittle material such as silica its counterintuitive fracture characteristics.

"The terms ‘brittle' and ‘ductile' are macroscopic terminology," Kim says. "It seems that these terms don't apply at the nanoscale."

Using an atomic force microscope (AFM), Kim and Namboodiri were able to look more closely at interfacial fracture than had been done before at the nanoscale. They found that the silica will stretch as much as gold or silver and will continue to deform beyond the point that would be predicted using its bulk-scale properties.

Hawa, Henz and Zachariah's simulations reaffirmed their study and added some additional details. They showed that both nanoparticle size and morphology—whether the material is basically crystalline or amorphous, for example—have an effect on the observed ductility and tensile strength because those factors influence the mobility of surface atoms. In the simulations, the smaller the particles in the aggregate the more ductile the material behaved. Crystalline structures exhibited greater strength when stressed and deformed long after the critical yield point observed macroscopically.

Namboodiri explained that although the work is very basic, these findings might one day inform the design of microelectronic mechanical devices.

* N. Pradeep, D-I. Kim, J. Grobelny, T. Hawa, B. Henz, and M. R. Zachariah. Ductility at the nanoscale: Deformation and fracture of adhesive contacts using atomic force microscopy. Applied Physics Letters, published online 15 November 2007.

** T. Hawa, B. Henz, and M. Zachariah. Computer simulations of nanoparticle aggregate fracture. Presented Wednesday, March 12, 2008, at the 2008 APS meeting in New Orleans, La.

####

About NIST
From automated teller machines and atomic clocks to mammograms and semiconductors, innumerable products and services rely in some way on technology, measurement, and standards provided by the National Institute of Standards and Technology.

Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Mark Esser

(301) 975-2767

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Silicon chip with integrated laser: Light from a nanowire: Nanolaser for information technology February 12th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Molecular Machines

'Spermbots' could help women trying to conceive (video) January 15th, 2016

Scientists blueprint tiny cellular 'nanomachine' December 17th, 2015

Nano-walkers take speedy leap forward with first rolling DNA-based motor: Fastest DNA motor holds potential for disease diagnostics December 1st, 2015

Rice makes light-driven nanosubmarines: Speedy single-molecule submersibles are a first November 16th, 2015

Molecular Nanotechnology

A fast solidification process makes material crackle February 8th, 2016

Nanodevice, build thyself: Researchers in Germany studied how a multitude of electronic interactions govern the encounter between a molecule called porphine and copper and silver surfaces January 18th, 2016

Nano-walkers take speedy leap forward with first rolling DNA-based motor: Fastest DNA motor holds potential for disease diagnostics December 1st, 2015

Rice makes light-driven nanosubmarines: Speedy single-molecule submersibles are a first November 16th, 2015

Discoveries

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Silicon chip with integrated laser: Light from a nanowire: Nanolaser for information technology February 12th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Materials/Metamaterials

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Chemical cages: New technique advances synthetic biology February 10th, 2016

Superconductivity: Footballs with no resistance - Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications February 9th, 2016

Announcements

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Silicon chip with integrated laser: Light from a nanowire: Nanolaser for information technology February 12th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic