What is Glass?

A new type of glass has been created. But first, what is glass? It is an odd substance that even to this day is not very well understood. Even though it seems solid, it is considered a liquid by some. This is primarily because of its random structure. The article on glass in Wikipedia calls it a “non-crystalline amorphous solid”.

What is Glass Made Of?

Glass is made by melting different minerals together at a high enough temperature. The primary one is silicon dioxide (about 75%) which is what sand is mostly made of. You may also know silicon dioxide as quartz. Sodium oxide, sodium carbonate and calcium oxide are the other primary constituents of glass.

Newly Discovered Glass

This new glass was discovered by accident. Rather than being random and amorphous, it has structure. They made the glass for a different reason, not expecting do discover glass with structure. But, when they tested their creation spectroscopically, instead of the random pattern that you usually get with glass, this sample had peaks and a definite pattern which indicated that the molecules in the glass were arranged in a regular pattern.

How to Make Structured Glass

Normally glass is made by melting the minerals together and pouring it out in a sheet or into a mold. With this glass they were doing vapor deposition. They heated up the glass and then would spray a thin layer at a time, over and over again until the layers built up and it became thick.

Temperature is critical in the process since you need to get the glass hot enough to melt and spray but not too hot because it then has to hit the newly formed glass and cool and solidify. So there is a very narrow temperature range which is feasible.

Key is Layering the Glass

By putting down a very thin layer at a time, it is thought that this traps the glass molecules in a certain orientation. Interestingly, once the glass cools and sets it keeps the orientation of all the molecules even if it is reheated. (Unless of course you go all the way to where it melts.)

Now, they are playing with the process and seeing how the properties of the glass change and how they can come up with different qualities and uses for these new types of glass. They will also probably modify the ingredients in the glass to see what effects they will have.