Self-strengthening nanocomposite gets stronger from repeated stress
March 25, 2011
Researchers at Rice University have created a synthetic material that gets stronger from repeated stress, much like the body strengthens bones and muscles after repeated workouts, says Pulickel Ajayan, professor of mechanical engineering, materials science, and chemistry.
The researchers tested the high-cycle fatigue properties of a polymer-based nanocomposite with carbon nanotube fillers by infiltrating a forest of vertically aligned, multiwalled nanotubes with polydimethylsiloxane (PDMS), an inert, rubbery polymer. Repeatedly stressing the material didn’t seem to damage it, but instead made it stiffer.
They used dynamic mechanical analysis (DMA) to test the material. They found that after 3.5 million compressions (five per second) over about a week’s time, the stiffness of the composite had increased by 12 percent and showed the potential for even further improvement.
Their work appears March in the journal ACS Nano.