Try bending a piece of glass, and it’ll likely shatter. But what if a different, stronger form of glass were possible?
Researchers at the University of Oregon put physics to the test and developed a mathematical solution for creating what they call the “ideal glass.” That is, glass is composed of molecules packed as tightly as possible, resulting in a material with a substantially higher melting point, greater flexibility and greater strength.
As of now, their findings are an abstract simulation that such a material is possible, at least on a two-dimensional scale within a computer.
But they set out to tackle a problem long thought impossible. Many had given up on it.
Now, they have something that other researchers can build off of as they seek the densest form of glass.
“It tells you that the very best can exist. It gives hope for making ever stronger glasses that can approach the very best,” said University of Oregon physicist Eric Corwin, who led the research, published in the journal Physical Review Letters.
Eric Corwin, a physicist at the University of Oregon
Charlie Litchfield / University of Oregon
Corwin isn’t just talking about window glass.
In physics, glass is any amorphous material: Something that can be melted into various states of malleability. His research would also have applications in plastics, rubber and silicon.
Although glass is a solid, it’s what’s called an amorphous solid.
It doesn’t have a fixed melting point and consists of disordered molecules, similar to a liquid. Those molecules are frozen in place, but haphazardly, with a lot of useless space in between them.
By contrast, there are crystalline solids — like aluminum.
These have fixed melting points. Pure aluminum, for instance, has a melting point of 1220.6 degrees. And the molecules in aluminum and other crystalline solids aren’t haphazard like in glass. They form a neat lattice pattern. They’re arranged in a way that doesn’t waste space, so it’s possible to make them as strong as they can be.
Corwin likened the distinction to people boarding a bus: if they enter in an orderly fashion, more people will fit.
Physicists have long theorized that if glass molecules can be packed into a denser structure, such as the one on the left, they could produce a stronger form of glass. Normally, glass molecules are arranged haphazardly, with a lot of wasted space between them, as shown in the image on the right.
Image courtesy of the University of Oregon
Scientists had long wondered whether they could produce stronger forms of glass by arranging molecules like crystalline solids, thereby packing them into their densest possible form.
In 1948, American chemist Walter Kauzmann hypothesized that glass could reach that state if cooled slowly enough. He concluded that it would require an infinite amount of time and therefore dismissed the idea.
For the last eight decades, scientists have put Kausmann’s paradox to the test, but they haven’t come up with a solution until now.
Corwin and his team began their research by reducing the problem to its simplest form.
They used computer modelling to draw two-dimensional versions of the molecules.
They found that glass molecules can pack into their densest form if they can resize as they are packed. Some would grow larger, and some would grow smaller; eventually, they would form a structure similar to that of crystalline solids.
The end result would be a material that is more resistant to pressure and heat.
“It would be an enormous advance,” Corwin said. “Because one of the benefits of glasses is that they can be molded into whatever structure you like in a way that you can’t with crystalline materials.”
Next, Corwin and his team will attempt to replicate their arguments on a three-dimensional scale.
