European researchers discover 'perfect glass'
clearer, more durable glass, a breakthrough that could help
companies present their food products in a high-quality package,
report Simon Pitman and Ahmed ElAmin.
The discovery could also be good news to glass manufacturers, who for many years have seen their business eroded by increasingly sophisticated resins that are cheaper to produce, stronger and often come with a finish that can match the quality ofglass.
In a joint research project, scientists from the UK, France and the European Synchrotron Radiation Facility (ESRF) monitored the change in the structure of zeolites, crystalline solids, which they claim helped to create an almost perfect glass when heated under controlled conditions that respected this structure.
The teams say they were able to do this by recording vibrations involving groups of atoms in zeolites that subsequently characterise the glass. The full results of the research were published in the last issue ofScience magazine.
Zeolites are porous crystalline aluminosilicates, presenting a regular arrangement of cages. In their natural state, they are components of soils and can be barriers against the migration of radioactive elements. Intheir synthetic form, zeolites are industrially applied as components of washing powders and in the refinement of petroleum to make gasoline.
Due to their structure, zeolites have a low-density configuration. They melt at around 900°C, lower temperatures than most similar materials, such as silica (sand), which melts at twice this temperature.
The scientists have discovered that if the heating process is carried out at a slower and more controlled rate, the microporous crystalline structure of the glass is disturbed. When the structures collapse, zeolites contract, becoming 60 per cent moredense than in their original form. The material then adopts the structure of an improved glass.
"We have discovered the triggering mechanism," said Neville Greaves, first author of the paper.
The scientists say that the upstart of the controlled heating is a mechanically and chemically stronger glass than the glass that is commonly used today.
"We believe this is the key to the synthesis of perfect glass", Greaves said.
Would this mean that, if dropped, glass bottles and packaging would be more difficult to break?
"This research could lead to that, but it is still far away," Greaves said. "This would also mean making glass invulnerable to water, for instance."
The current study is on-going and the researchers say that the final aim is to find out the conditions in which the perfect glass forms.
The advent of alternatives to glass has meant that glass packaging manufacturers have had to move fast to meet the tough competition resins now provide. US company Eastman Chemicals recently launched a glass polymer that it has developed specifically for premium cosmetics and fragrance products. The company claims that the flexibility of Eastar Copolyester EB062 means that it can be blow-moulded into a broad range of shapes using a thick wall that does not compromise quality.
