Ultra-stable glass could lead to creation of faster-acting drugs

New research on making glass more stable could lead to the creation of stronger metals and faster-acting drugs, researchers claim.

Scientists at the universities of Chicago and Wisconsin-Madison in the US say they have shown that glass manufactured on specially prepared surfaces can have the molecular stability of glass that has been aged for hundreds of years.

They argue that their research on the amorphous molecular structure of this glass could aid the creation of drugs that don’t crystallise during storage and so can be delivered faster in the bloodstream, as well as the development of amorphous metals that are better at absorbing impacts.

By simulating the specialist manufacturing of glass with a computer, the researchers were able to confirm their theory that the new glass’s molecular structure was similar to that of old glass, according to Chicago’s Prof Juan de Pablo, who co-authored a report on the work published in Nature Materials.

‘It had been believed until now that there is no correlation between the mechanical properties of a glass and the molecular structure; that somehow the properties of a glass are “hidden” somewhere and that there are no obvious structural signatures,’ he said in a statement.

‘What we found here is that there are actually differences — it’s just that you had to create better glassy materials. Once you create these materials, you see that the structure and the differences between ordinary and stable glasses are clearly there and are actually pronounced.’

Ultra-stable glass can be grown by vapour deposition in a vacuum chamber, where a material is heated, vaporised and then condensed on an experimental surface.

Chicago University ultra-stable glass molecules
In this simulation of ultra-stable glass, phosphorus and nickel atoms were introduced onto the pink substrate a few at a time in a molecular dynamics simulation

Another of the researchers, Mark Ediger at Wisconsin-Madison, speculated that the glass grown under these conditions produced a material similar to glass that has become more stable over time rather than a new class of material.

Using a simulation created by Sadanand Singh, also of Wisconsin-Madison, Ediger was able to demonstrate that the deposition process gives the glass molecules extra room to arrange themselves into a more stable configuration.

The research also showed that to get the most stable glass the molecules have to descend under the right conditions in order to create the most efficiently arranged structure without any holes.

‘If you either rain the molecules too fast or choose a low temperature at which there’s no mobility at the surface, then this trick doesn’t work,’ said Ediger.

‘Then it would be like taking a bucket of odd-shaped pieces and just dumping them on the floor. There are all sorts of voids and gaps because the molecules didn’t have any opportunity to find a good way of packing.’