Glassy gels are a brand new class of supplies which are as laborious as plastic however extraordinarily stretchy
Meixiang Wang, NC State College
Whenever you consider gel, you may think goo – however a brand new gel-like materials has been engineered to be comfortable sufficient to stretch to nearly seven instances its unique size whereas nonetheless being sturdy and clear, like glass.
Michael Dickey at North Carolina State College says his workforce found these “glassy gels” when his scholar, Meixiang Wang, was experimenting with ionic liquids and saved discovering sudden mechanical properties. The supplies they devised are greater than 50 per cent liquid, however as sturdy because the plastics used for water bottles, whereas additionally being very stretchy and sticky. “There are a bunch of cool things about them,” he says.
Every glassy gel consists of lengthy molecules known as polymers combined with an ionic liquid, a fluid that’s basically a salt in liquid kind. The gel is a clear strong that may stand up to as much as 400 instances atmospheric strain, but additionally stretch very simply as much as 670 per cent. Dickey says that this might make it well-suited for constructing comfortable robotic grippers or 3D printing deformable supplies.
He and his colleagues made glassy gels from a number of completely different mixtures of polymers and liquid salts and located that their power and stretch relied on the exact ratio used.
“Just by changing the ratio of two ingredients, you can go from something very stretchy like a rubber band, to something almost as hard as glass,” says Dickey.
It’s because the supplies get their stretchiness from the ionic liquid settling into areas between the stiffer polymer molecules and pushing them aside, whereas their power comes from the electrostatic attraction between the liquid’s charged particles and the polymers, which prevents them from absolutely breaking away from one another.
The glassy gels may also self-heal – a lower or break may be repaired by making use of warmth, which makes molecules on the damaged edges reconnect. Richard Hoogenboom at Ghent College in Belgium says this might make them helpful in some situations when standard plastics are used, however the system could must be tweaked in order that it solely softens at temperatures excessive sufficient so this doesn’t occur unintentionally.
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