Results challenge classic theories of glass transition
behavior.
Fact or fiction? Stained glass found in medieval cathedrals
becomes thicker at the bottom because glass moves over time. For years
researchers have had their doubts, now a team at Texas Tech University has
further evidence that the glass is not going anywhere.
“Glass transition is related to the performance of
materials, whether it is inorganic glass or organic polymers,” said Gregory
McKenna, professor of chemical engineering at Texas Tech. “For example, this
would be important to people who own a boat made of fiberglass, or fly in an
airplane made with epoxy-based composites. Information like that can help
predict if that jet will still be flying in 30 years.”
The idea for this research came from a doctoral student’s
qualifying exam, McKenna said. He gave Jing Zhao a problem relating to
diverging time-scales using polyvinyl acetate, a substance often found in
adhesives. Her results were consistent with a lack of divergence – contrary to
received thought. So they decided to up the ante by performing similar
experiments on a much older, ultra-stable glass.