New plastics `bleed` when cut or scratched and heal like human skin

   Mar 27, 12:46 pm

Washington, March 27 (ANI): Scientists have developed a new genre of plastics that mimic the human skin’s ability to heal scratches and cuts.

The plastics, which change colour to warn of wounds and heal themselves when exposed to light, offer promise of endowing cell phones, laptops, cars and other products with self-repairing surfaces.

“Mother Nature has endowed all kinds of biological systems with the ability to repair themselves,” explained Professor Marek W. Urban, Ph.D., who reported on the research.

“Some we can see, like the skin healing and new bark forming in cuts on a tree trunk. Some are invisible, but help keep us alive and healthy, like the self-repair system that DNA uses to fix genetic damage to genes. Our new plastic tries to mimic nature, issuing a red signal when damaged and then renewing itself when exposed to visible light, temperature or pH changes,” he explained.

Urban, who is with the University of Southern Mississippi in Hattiesburg foresees a wide range of potential applications for plastic with warn-and-self-repair capabilities.

Scratches in automobile fenders, for instance, might be repaired by simply exposing the fender to intense light. Critical structural parts in aircraft might warn of damage by turning red along cracks so that engineers could decide whether to shine the light and heal the damage or undertake a complete replacement of the component. And there could be a range of applications in battlefield weapons systems.

Plastics have become so common, replacing steel, aluminum, glass, paper and other traditional materials because they combine desirable properties such as strength, light weight and corrosion resistance. Hundreds of scientists around the world have been working, however, to remedy one of the downsides of these ubiquitous materials: Once many plastics get scratched or cracked, repairs can be difficult or impossible.

Self-healing plastics have become a Holy Grail of materials science. One approach to that goal involves seeding plastics with capsules that break open when cracked or scratched and release repairing compounds that heal scratches or cuts. Another is to make plastics that respond to an outside stimulus — like light, heat or a chemical agent — by repairing themselves.

Urban’s group developed plastics with small molecular links or “bridges” that span the long chains of chemicals that compose plastic.

When plastic is scratched or cracked, these links break and change shape. Urban tweaked them so that changes in shape produce a visible colour change — a red splotch that forms around the defect. In the presence of ordinary sunlight or visible light from a light bulb, pH changes or temperature, the bridges reform, healing the damage and erasing the red mark.

Urban cited other advantages of the new plastic. Unlike self-healing plastics that rely on embedded healing compounds that can self-repair only once, this plastic can heal itself over and over again.

The material also is more environmentally friendly than many other plastics, with the process for producing the plastic water-based, rather than relying on potentially toxic ingredients. And his team now is working on incorporating the technology into plastics that can withstand high temperatures.

The researcher described the unusual plastics at the 243rd National Meeting and Exposition of the American Chemical Society (ACS), the world’s largest scientific society. (ANI)
 

NHRC organises national conference on Silicosis Jul 23, 4:25 pm
New Delhi, July 23 (ANI): The National Human Rights Commission (NHRC) this year is organizing a day-long conference on Silicosis at the India International Centre here on July 25.
Full Story
Why kids tend to be impulsive Jul 23, 4:25 pm
Washington, July 23 (ANI): A new study has linked impulsiveness in kids to brain connectivity.
Full Story
Twins have low language performance in comparison to single-born kids Jul 22, 4:30 pm
Washington, July 22 (ANI): A recent study has revealed that the rate of language delay among twins is almost twice as compared to the single-born children.
Full Story
'Natural cooling fluctuation' masked greenhouse effect during last decade: Study Jul 22, 4:30 pm
Washington, July 22 (ANI): A new study has revealed that a natural cooling fluctuation between 1998 and 2013 largely masked the warming effects of a continued increase in man-made emissions of carbon dioxide and other greenhouse gases.
Full Story
Comments

LATEST STORIES
TOP VIDEO STORIES
PHOTO GALLERY