Navigation Links
Only the weak survive?: Pitt team adds more give for stronger self-healing materials
Date:3/22/2011

PITTSBURGHConventional rules of survival tend to favor the strongest, but University of Pittsburgh-based researchers recently found that in the emerging world of self-healing materials, it is the somewhat frail that survive.

The team presents in the journal Langmuir a new model laying out the inner workings of self-healing materials made of nanoscale gel particles that can regenerate after taking damage and are being pursued as a coating or composite material. Moreover, the researchers discovered that an ideal amount of weak bonds actually make for an overall stronger material that can withstand more stress.

Although self-healing nanogel materials have already been realized in the lab, the exact mechanical nature and ideal structure had remained unknown, explained Anna Balazs, corresponding author and Distinguished Professor of Chemical Engineering in Pitt's Swanson School of Engineering. The team's findings not only reveal how self-healing nanogel materials work, but also provide a blueprint for creating more resilient designs, she said. Balazs worked with lead author and Pitt postdoctoral researcher Isaac Salib; Chet Gnegy, a Pitt chemical and petroleum engineering sophomore; German Kolmakov, a postdoctoral researcher in Balazs' lab; and Krzysztof Matyjaszewski, a chemistry professor at Carnegie Mellon University with a special appointment in Pitt's Department of Chemical and Petroleum Engineering.

The team worked from a computational model Gnegy, Kolmakov, and Salib created based on a self-healing material Matyjaszewski developed known as nanogel, a composition of spongy, microscopic polymer particles linked to one another by several tentacle-like bonds. The nanogel particles consist of stable bondswhich provide overall strengthand labile bonds, highly reactive bonds that can break and easily reform, that act as shock absorbers.

The computer model allowed the researchers to test the performance of various bond arrangements. The polymers were first laid out in an arrangement similar to that in the nanogel, with the tentacles linked end-to-end by a single strong bond. Simulated stress tests showed, however, that though these bonds could recover from short-lived stress, they could not withstand drawn out tension such as stretching or pulling. Instead, the team found that when particles were joined by several parallel bonds, the nanogel could absorb more stress and still self-repair.

The team then sought the most effective concentration of parallel labile bonds, Balazs said. According to the computational model, even a small number of labile bonds greatly increased resilience. For instance, a sample in which only 30 percent of the bonds were labilewith parallel labile bonds placed in groups of fourcould withstand pressure up to 200 percent greater than what could fracture a sample comprised only of stable bonds.

On the other hand, too many labile linkages were so collectively strong that the self-healing ability was cancelled out and the nanogel became brittle, the researchers report.

The Pitt model is corroborated by nature, which engineered the same principle into the famously tough abalone shell, Balazs said. An amalgamation of microscopic ceramic plates and a small percentage of soft protein, the abalone shell absorbs a blow by stretching and sliding rather than shattering.

"What we found is that if a material can easily break and reform, the overall strength is much better," she said. "In short, a little bit of weakness gives a material better mechanical properties. Nature knows this trick."


'/>"/>

Contact: Morgan Kelly
mekelly@pitt.edu
412-897-1400
University of Pittsburgh
Source:Eurekalert

Related biology technology :

1. Information warfare in the 21st century: Ideas are sometimes stronger than bombs
2. New Leadership Team at International Trachoma Initiative to Build Stronger Partnerships to Eliminate Blinding Trachoma
3. Information warfare in the 21st century: Ideas are sometimes stronger than bombs
4. Information warfare in the 21st century: Ideas are sometimes stronger than bombs
5. Dry adhesive based on carbon nanotubes gets stronger, with directional gripping ability
6. Argentum Medical Issues Response to Recent Decision in Litigation With Noble Biomaterials
7. Rutgers researchers identify materials that may deliver more bounce
8. Reportlinker Adds Global Biocompatible Materials Industry
9. New nanomaterials unlock new electronic and energy technologies
10. New materials may bring advanced optical technologies, cloaking
11. Carbon-Based Nano-Materials and Devices Conference
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/17/2017)... Village, CA (PRWEB) , ... August 17, 2017 ... ... technology for cancer research and personalized medicine, today announced the launch of a ... Kansas City, Missouri. The study’s goal is to evaluate the potential for early ...
(Date:8/16/2017)... ... 16, 2017 , ... Recent studies show that cancer cells ... specific cancers, such as breast, prostate, or lung, target vital pathways active in ... advanced prostate cancer. , This therapy limits the production and effectiveness of ...
(Date:8/16/2017)... MN (PRWEB) , ... August 16, 2017 , ... ... our third U.S. Food and Drug Administration (FDA) inspection at our Dilworth, MN ... No 483 was issued. This inspection was conducted as part of a routine ...
(Date:8/15/2017)... After spending the past two years building a state-of-the-art technology which ... offers this platform to healthcare stakeholders (hospitals, foundations, biopharma companies etc.) ... collection vis a vis their members, under their own brand. Three ... offer. ... ...
Breaking Biology Technology:
(Date:3/24/2017)... Mar 24, 2017 Research and Markets has ... Market Analysis & Trends - Industry Forecast to 2025" report ... ... at a CAGR of around 15.1% over the next decade to ... report analyzes the market estimates and forecasts for all the given ...
(Date:3/23/2017)... 2017 Research and Markets has announced the ... Trends - Industry Forecast to 2025" report to their offering. ... The Global ... of around 8.8% over the next decade to reach approximately $14.21 ... market estimates and forecasts for all the given segments on global ...
(Date:3/22/2017)... NEW YORK , March 21, 2017 /PRNewswire/ ... Customer Marketing Cloud used by retailers such as ... in its platform — Product Recommendations and Replenishment. Using ... to give more personalized product and replenishment recommendations ... purchases, but also on predictions of customer intent ...
Breaking Biology News(10 mins):