Breakthrough in the search for a perfect glass

Clearer, longer lasting glass could be a step closer thanks to research by European scientists. A paper published in Science magazine on 27 May 2005 presents the findings of a joint project involving …

Clearer, longer lasting glass could be a step closer thanks to research by European scientists. A paper published in Science magazine on 27 May 2005 presents the findings of a joint project involving scientists from the UK, France and the European Synchrotron Radiation Facility, who studied the change in the structure of crystalline aluminosilicates, or zeolites, which when heated under controlled conditions make an almost perfect glass. Zeolites are porous crystalline aluminosilicates, presenting a regular arrangement of cages. They are used in their synthetic form as components of washing powders and in petrol refining. Due to their cage structure, zeolites have a low-density structure. They melt at around 900 degrees C, a lower temperature than most similar materials. If the heating is carried out at a slow rate, low-frequency vibrational modes are responsible for destabilizing the microporous crystalline structure. When the cages collapse, zeolites contract, becoming 60% denser than in their original form, and they adopt the structure of a glass. “We have discovered the triggering mechanism”, said Neville Greaves, lead author of the paper. The resulting glass is mechanically and chemically stronger than current glasses. “We believe this is the key to the synthesis of perfect glasses”, asserted Greaves, although he conceded that much more research was needed.