Materials

New type of glass made of metal organic compounds breaks tradition

New type of glass made of meta...
Researchers have created a new type of glass, dubbed ZIF-62, made from metal-organic compounds
Researchers have created a new type of glass, dubbed ZIF-62, made from metal-organic compounds
View 2 Images
The atomic structure of ZIF-62, showing a zinc atom surrounded by imidazolate and benzimidazolate molecules
1/2
The atomic structure of ZIF-62, showing a zinc atom surrounded by imidazolate and benzimidazolate molecules
Researchers have created a new type of glass, dubbed ZIF-62, made from metal-organic compounds
2/2
Researchers have created a new type of glass, dubbed ZIF-62, made from metal-organic compounds

The glass we're most familiar with is made from silicon dioxide, but materials like boron, polymers and metals have also been used. Now, an international team of scientists have developed a brand new class of glass, made from metal-organic compounds. These new materials form glass more readily than other types, and are much more pliable.

The new metal-organic glass is made of zinc and two organic compounds, known as imidazolate and benzimidazolate. The material has the same atomic structure as silica glass, forming a pyramid shape with a zinc atom at the center and four molecules of the organic compounds surrounding it. The researchers called their creation ZIF-62.

The atomic structure of ZIF-62, showing a zinc atom surrounded by imidazolate and benzimidazolate molecules
The atomic structure of ZIF-62, showing a zinc atom surrounded by imidazolate and benzimidazolate molecules

One of the defining characteristics of glass is its smooth, non-crystalline structure, and that's the result of a very careful balancing act during production. Whatever source material is used needs to be heated until it melts, then cooled very rapidly so that crystals don't have time to form. How well a material avoids crystallization is known as its glass-forming ability.

Traditionally, silica glass is known to have the best glass-forming ability, but according to the team, ZIF-62 has it beat. In fact, it outperformed 50 existing types of glass, and is far more pliable than silica-based glass. Tweaking the recipe, the researchers found that the more benzimidazolate they added, the better the material's glass-forming ability became.

There are still kinks to be ironed out though. The process for manufacturing silica glass benefits from thousands of years of refinement, and it's hard for ZIF-62 to compete with that at this early stage. To make the new metal-organic glass, the organic compounds first need to be synthesized, then mixed with hydrous zinc nitrate and a solvent. Then, it all needs to be heated to about 800° F (427° C) for long enough to completely melt – but if it hits 980° F (527° C) it will start to vaporize.

Finding ways to scale up production is a key area of future work, as is learning more about the glass itself. So far the researchers have experimented with ZIF-62's optical and mechanical properties, but there's plenty more still to learn, the team says.

"This family of glasses is so new that, while we have determined its glass-forming ability and a few other properties, we have not fully characterized all of its material properties," says John C. Mauro, co-author of a study describing the new material. "There also needs to be research into how to scale-up this process for manufacturing."

This further study will also examine other metallic-organic glass recipes, including a potential cobalt-based glass.

The research was published in the journal Science Advances.

Source: Pennsylvania State University

10 comments
MartinVoelker
The melting temperatures appear to be vastly lower that what is needed to melt sand - that's good. But I doubt they'll be as cheap and ubiquitous as sand, so we're probably looking at specialised use cases only.
Bob Stuart
So - no promising properties yet?
Aross
But will it be recyclable or just another pest material to grace the landfill sites????
notarichman
how about a building fire? toxic fumes? will the vapor be combustible? being a "liquid" like glass; will it flow like glass? hardness? suitable for eye glasses? lots of questions!
Fretting Freddy the Ferret pressing the Fret
A much lower melting temperature means a big potential to save production cost. At least, from an energy-cost perspective.
RoGuE_StreaK
"ZIF-62"??! Surely this is the ideal opportunity to bring "Transparisteel" from science fiction into reality?
S Michael
What benefit is this to mankind? Right now I see very little other than it's employing scientist to spend money on "maybe." Seems to me it would be much cheaper to recycle glass instead of making more landfill problems. Have they looked at adding these elements to recycled glass and what it might give us?
Metalic glass... Didn't I see this in a Star Trek movie?
ChairmanLMAO
Building a Cloudbuster in my head already!
Mark K.
Yes, transparent aluminum already exists, Star Trek was right with that prediction ... sorta.
Don Duncan
Aross & S. Michael: The world doesn't have a "land-fill" problem. It has a "gov monopoly on garbage disposal problem".