Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Catalyst-free chemistry makes self-healing materials more practical

A new catalyst-free, self-healing material system developed by Jeffrey Moore, the Murchison-Mallory Professor of Chemistry at Illinois, is flanked by Scott White, a professor of aerospace engineering, and Nancy Sottos, a professor of materials science and engineering, offers a far less expensive and far more practical way to repair composite materials used in structural applications ranging from airplane fuselages to wind-farm propeller blades.
A new catalyst-free, self-healing material system developed by Jeffrey Moore, the Murchison-Mallory Professor of Chemistry at Illinois, is flanked by Scott White, a professor of aerospace engineering, and Nancy Sottos, a professor of materials science and engineering, offers a far less expensive and far more practical way to repair composite materials used in structural applications ranging from airplane fuselages to wind-farm propeller blades.

Abstract:
A new catalyst-free, self-healing material system developed by researchers at the University of Illinois offers a far less expensive and far more practical way to repair composite materials used in structural applications ranging from airplane fuselages to wind-farm propeller blades.

Catalyst-free chemistry makes self-healing materials more practical

CHAMPAIGN, IL | Posted on November 27th, 2007

The new self-healing system incorporates chlorobenzene microcapsules, as small as 150 microns in diameter, as an active solvent. The expensive, ruthenium-based Grubbs' catalyst, which was required in the researchers' first approach, is no longer needed.

"By removing the catalyst from our material system, we now have a simpler and more economical alternative for strength recovery after crack damage has occurred," said Jeffrey Moore, the Murchison-Mallory Professor of Chemistry at Illinois. "Self-healing of epoxy materials with encapsulated solvents can prevent further crack propagation, while recovering most of the material's mechanical integrity."

The new chemistry is described in a paper accepted for publication in Macromolecules, and posted on the journal's Web site.
During normal use, epoxy-based materials experience stresses that can cause cracking, which can lead to mechanical failure. Autonomous self-healing - a process in which the damage itself triggers the repair mechanism - can retain structural integrity and extend the lifetime of the material.

"Although we demonstrated the self-healing concept with a ruthenium-based catalyst, the cost of the catalyst made our original approach too expensive and impractical," said Moore, who also is affiliated with the university's Frederick Seitz Materials Research Laboratory and with the Beckman Institute. "Our new self-healing system is simple, very economical and potentially robust."

In the researchers' original approach, self-healing materials consisted of a microencapsulated healing agent (dicyclopentadiene) and Grubbs' catalyst embedded in an epoxy matrix. When the material cracked, microcapsules would rupture and release the healing agent, which then reacted with the catalyst to repair the damage.

In their new approach, when a crack forms in the epoxy material, microcapsules containing chlorobenzene break. The solvent disperses into the matrix, where it finds pockets of unreacted epoxy monomers. The solvent then carries the latent epoxy monomers into the crack, where polymerization takes place, restoring structural integrity.

In fracture tests, self-healing composites with catalyst-free chemistry recovered as much as 82 percent of their original fracture toughness.

The new catalyst-free chemistry has taken down the barriers to cost and level of difficulty, Moore said. "From an economics and simplicity standpoint, self-healing materials could become part of everyday life."

With Moore, co-authors of the paper are graduate student and lead author Mary Caruso, former postdoctoral research associate David Delafuente (now a chemistry and physics professor at Augusta State University), visiting University of Texas at Austin undergraduate student Victor Ho, materials science and engineering professor Nancy Sottos, and aerospace engineering professor Scott White.

The work was funded by the Air Force Office of Scientific Research and the National Science Foundation.

####

For more information, please click here

Contacts:
James E. Kloeppel
Physical Sciences Editor
217-244-1073


Jeffrey Moore
217-244-4024


Copyright © University of Illinois

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

Materials/Metamaterials

Making quantum puddles: Physicists discover how to create the thinnest liquid films ever June 13th, 2018

Nickel ferrite promotes capacity and cycle stability of lithium-sulfur battery June 13th, 2018

Evidence for a new property of quantum matter revealed: Electrical dipole activity detected in a quantum material unlike any other tested June 11th, 2018

Nano-saturn: Supramolecular complex formation: Anthracene macrocycle and C60 fullerene June 8th, 2018

Announcements

JPK talks with Dr Frank Lafont, Director of the BioImaging Center Lille (BICeL) about the use of the NanoWizardŽ AFM together with fluorescence microscopy in the study of living cells June 19th, 2018

Powering the 21st Century with Integrated Photonics: UCSB-Led Team Selected for Demonstration of a Novel Waveguide Platform Which is Transparent Throughout the MWIR and LWIR Spectral Bands June 19th, 2018

Executives Explore Key Megatrends and Innovations in MEMS, Sensors, Imaging Tech at SEMI-MSIG European Summits: Speakers to share developments in smart automotive, smart cities, smart industrial, biomedical, consumer and IoT, September 19-21, 2018 in Grenoble, France June 19th, 2018

Carbon nanotube optics poised to provide pathway to optical-based quantum cryptography and quantum computing: Researchers are exploring enhanced potential of carbon nanotubes for unique applications June 18th, 2018

Aerospace/Space

Disability Can Be a Superpower in Space Disabled astronauts offer unique solutions to emergencies in space May 17th, 2018

SpaceX Founding Employee Tom Mueller to Speak at International Space Development Conference May 15th, 2018

Shrimp, Soybeans, and Tomatoes Top the Menu in Cities in Space May 10th, 2018

National Space Society Applauds NASA's Support for Commercial Low Earth Orbit Space Stations May 2nd, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project