Researchers at Chalmers University of Technology, Sweden, have succeeded in creating a new type of super-stable, durable glass with potential applications ranging from medicines, advanced digital screens, and solar cell technology. The study shows how mixing multiple molecules - up to eight at a time - can result in a material that performs as well as the best currently known glass formers. A glass, also known as an 'amorphous solid', is a material that does not have a long-range ordered structure - it does not form a crystal. Crystalline materials on the other hand, are those with a highly ordered and repeating pattern. The fact that a glass does not contain crystals is what makes it useful.
Researchers are therefore always interested in finding new ways to encourage different materials to form this amorphous state, which can potentially lead to the development of new types of glass with improved properties and new applications. The new study, recently published in the scientific journal Science Advances, represents an important step forward in that search. Best result for any glass forming material
The researchers experimented with a mixture of up to eight different perylene molecules which, individually, have a high fragility - a property related to how easy it is for a material to form a glass. But mixing many molecules resulted in a substantial decrease in fragility, and a very strong glass former with ultralow fragility was formed.
Extending product life and saving resources
Another application that may benefit from more stable glasses are pharmaceuticals. Amorphous drugs dissolve more quickly, which aids rapid uptake of the active ingredient upon ingestion. Hence, many pharmaceuticals make use of glass-forming drug formations. For pharmaceuticals it is vital that the glassy material does not crystallise over time. The more stable the glassy drug, the longer the shelf life of the medicine.
More about the research
- The scientific article "Vitrification of octonary perylene mixtures with ultralow fragility" has been published in the scientific journal Science Advances and is written by Sandra Hultmark, Alex Cravcenco, Khuschbu Khushwaha, Suman Mallick, Paul Erhardt, Karl Börjesson and Christian Müller. The researchers are active at Chalmers University of Technology and the University of Gothenburg
- The researchers chose to work with a series of small, conjugated molecules comprising a perylene core with different pendant alkyl groups at one of the bay positions. All eight perylene derivatives readily crystallise when cast from solution and show a fragility of more than 70.
- Mixing of eight perylene derivatives resulted in a material that displays a fragility of only 13, which is a record low value for any glass forming material studied to date, including polymers and inorganic materials such as bulk metallic glasses and silicon dioxide.
- The research project was funded by the Swedish Research Council, the European Research Council, as well as the Knut and Alice Wallenberg Foundation through project: Mastering Morphology for Solution-born Electronics.
