It’s nearly impossible to go through a day without encountering polymers–molecules that play a part in paint, plastic, food packaging, car and plane parts, clothes, cell phones, computers, and even spaceships. That’s why an announcement today that IBM researchers have discovered a new class of polymers for the first time in decades is so interesting. The polymers in this class are self-healing, stronger than bone, and infinitely recyclable back to their starting material.
The ability to selectively recycle a structural component of a material could have an especially significant impact in the semiconductor and advanced manufacturing industry. Companies could rework high-value but defective manufactured parts or chips instead of throwing them into landfills. This would bolster fabrication yields for chips while saving money and significantly decreasing waste..
According to a paper published today in Science, scientists from IBM Research have come up with two related types of polymers: one that’s mostly liquid, elastic, and self healing (if you cut it in half and put it back together, it heals completely), and another that’s super-strong. The liquid polymer, called an organogel, can be reduced back to its starting component by dousing it in water, while the strong polymer can be broken down by dissolving it in acid.
“Once you have that in its pure form, you can use that starting material for any polymer that you want,” explains Jeannette M. Garcia, a researcher at IBM Research and the lead author of the paper. “You’re able to get back to the pure starting material. Usually with recycling, you’re melting things down and have to remold them, and the second time around the properties aren’t as good as the first time.”
Plenty of researchers are looking at organogels and ultra-strong polymers, but the recyclability of the polymer class discovered by IBM could lead to all sorts of new applications. Typically, if an electronics manufacturer makes a chip and there are defects, they have to scrap everything. But if they used IBM’s super-strong polymer, for example, they could take the chip, dissolve it in acid, and rebuild it (or use the components for something else). The organogel could, perhaps, be used in a nail polish that washes off with water instead of acetone. Or maybe it could be used in a wound gel that can simply be washed away once a therapeutic chemical has been released.
“The application space is wide open. There may be things we don’t even know,” says Garcia.
Like so many scientific discoveries, the super-strong polymer was found by accident. While in the lab mixing components for a known polymer together, Garcia accidentally left one of the components out of the mix. She soon looked at her flask, only to see that there was a strong solid material sitting at the bottom–so strong that she had to break the flask to get the polymer out, and then use a hammer to break it. The organogel, however, was made on purpose.