Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > MIT: Nanocomposities yield strong, stretchy fibers

Abstract:
Creating artificial substances that are both stretchy and strong has long been an elusive engineering goal. Inspired by spider silk, a naturally occurring strong and stretchy substance, MIT researchers have now devised a way to produce a material that begins to mimic this combination of desirable properties.

MIT: Nanocomposities yield strong, stretchy fibers

Cambridge, MA | Posted on January 19th, 2007

Such materials, known as polymeric nanocomposites, could be used to strengthen and toughen packaging materials and develop tear-resistant fabrics or biomedical devices. Professor Gareth McKinley, graduate student Shawna Liff and postdoctoral researcher Nitin Kumar worked at MIT's Institute for Soldier Nanotechnologies (ISN) to develop a new method for effectively preparing these materials. The research appears in the January issue of Nature Materials.

Engineers are already able to create materials that are either very strong or very stretchy, but it has been difficult to achieve both qualities in the same material. In the last few years scientists have determined that the secret behind the combined strength and flexibility of spider silk lies in the arrangement of the nano-crystalline reinforcement of the silk while it is being produced.

"If you look closely at the structure of spider silk, it is filled with a lot of very small crystals," says McKinley, a professor of mechanical engineering. "It's highly reinforced."

The silk's strength and flexibility come from this nanoscale crystalline reinforcement and from the way these tiny crystals are oriented towards and strongly adhere to the stretchy protein that forms their surrounding polymeric matrix.

Liff, a Ph.D. student in mechanical engineering, and Kumar, a former MIT postdoctoral associate, teamed up to figure out how to begin to emulate this nano-reinforced structure in a synthetic polymer (A polymer or plastic consists of long chains composed of small repeating molecular units). Numerous earlier unsuccessful attempts, tackling the same issue, relied on heating and mixing molten plastics with reinforcing agents, but Liff and Kumar took a different approach: They focused on reinforcing solutions of a commercial polyurethane elastomer (a rubbery substance) with nanosized clay platelets.

They started with tiny clay discs, the smallest they could find (about 1 nanometer, or a billionth of a meter thick and 25 nanometers in diameter). The discs are naturally arranged in stacks like poker chips, but "when you put them in the right solvent, these 'nanosized poker chips' all come apart," said McKinley.

The researchers developed a process to embed these clay chips in the rubbery polymer-first dissolving them in water, then slowly exchanging water for a solvent that also dissolves polyurethane. They then dissolved the polymer in the new mixture, and finally removed the solvent. The end result is a "nanocomposite" of stiff clay particles dispersed throughout a stretchy matrix that is now stronger and tougher.

Importantly, the clay platelets are distributed randomly in the material, forming a structure much like the jumble that results when you try to stuff matches back into a matchbox after they have all spilled out.
Instead of a neatly packed arrangement, the process results in a very disorderly "jammed" structure, according to McKinley. Consequently the nanocomposite material is reinforced in every direction and the material exhibits very little distortion even when heated to temperatures above 150 degrees Celsius.

In a Nature Materials commentary that accompanied the research paper, Evangelos Manias, professor of materials science and engineering at the University of Pennsylvania, suggests that "molecular composites" such as those developed by the MIT group are especially suitable for new lightweight membranes and gas barriers, because the hard clay structure provides extra mechanical support and prevents degradation of the material even at high temperatures. One possible use for such barriers is in fuel cells.

The U.S. military is interested in such materials for use in possible applications such as tear-resistant films or other body-armor components. The military is also interested in thinner, stronger packaging films for soldiers' MREs (meals ready to eat) to replace the thick and bulky packaging now used.

Fabric companies have also expressed interest in the new materials, which can be used to make fibers similar to stretchy compounds such as nylon or Lycra. The new approach to making nanocomposites can also be applied to biocompatible polymers and could be used to make stents and other biomedical devices, McKinley said.

The research was funded by the U.S. Army through MIT's Institute for Soldier Nanotechnologies and by the National Science Foundation. McKinley's team was assisted by technical staff at the ISN, including research engineer Steven Kooi, who helped prepare special samples for transmission electron microscopy.

####

About Massachusetts Institute of Technology
The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the 21st century.

The Institute is committed to generating, disseminating, and preserving knowledge, and to working with others to bring this knowledge to bear on the world's great challenges. MIT is dedicated to providing its students with an education that combines rigorous academic study and the excitement of discovery with the support and intellectual stimulation of a diverse campus community. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

For more information, please click here

Contacts:
Elizabeth A. Thomson, MIT News Office
617-258-5402

Copyright © Massachusetts Institute of Technology

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

Nanomedicine

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Scientists announce the quest for high-index materials: All-dielectric nanophotonics: The quest for better materials and fabrication techniques July 22nd, 2017

Probiotics: Novel biosynthetic tool to develop metallic nanoparticles: This research article by Dr. Nida Akhtar et al has been published in Recent Patents on Drug Delivery & Formulation, Volume 11, Issue 1, 2017 July 20th, 2017

Discoveries

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

Getting closer to porous, light-responsive materials: A new flexible material changes its porous nature when exposed to light July 27th, 2017

First Capacitive Transducer with 13nm Gap July 27th, 2017

Materials/Metamaterials

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Carbon displays quantum effects July 13th, 2017

Announcements

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

Getting closer to porous, light-responsive materials: A new flexible material changes its porous nature when exposed to light July 27th, 2017

First Capacitive Transducer with 13nm Gap July 27th, 2017

Military

Nanoparticles could spur better LEDs, invisibility cloaks July 19th, 2017

'Upconverted' light has a bright future: Rice University professor developing plasmon-powered devices for medicine, security, solar cells July 17th, 2017

Nature-inspired material uses liquid reinforcement: Rice U. nanoengineers create liquid-solid composites using clues from nature July 11th, 2017

Meniscus-assisted technique produces high efficiency perovskite PV films July 7th, 2017

Textiles/Clothing

Carbodeon demonstrates NanoDiamond nickel coatings with enhanced tribological properties June 7th, 2017

New ultrafast flexible and transparent memory devices could herald new era of electronics April 1st, 2017

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Engineers develop new magnetic ink to print self-healing devices that heal in record time November 7th, 2016

Fuel Cells

Argonne National Laboratory’s Continuous ALD Technology Licensed Exclusively to Forge Nano July 7th, 2017

Electrocatalyst nanostructures key to improved fuel cells, electrolyzers June 5th, 2017

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst May 18th, 2017

MIT Energy Initiative awards 10 seed fund grants for early-stage energy research May 4th, 2017

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