Changes in a liquid as it becomes a glass are related to repulsion between its atoms as they are crowded together. Although scientists have long believed the poorly understood glass transition must have atomic underpinnings, this is the first time they have been demonstrated experimentally.
Only recently has it become possible to accurately “see” the structure of a liquid. Using X-rays and a high-tech apparatus that holds liquids without a container, a physicist at Washington University in St. Louis has compared the behavior of glass-forming liquids as they approach the glass transition. The results are the strongest demonstration yet that bulk properties like viscosity are linked to microscopic ones like structure.
A team led by physicist Ken Kelton, PhD, is building an electrostatic levitation chamber that will be installed at the Spallation Neutron Source at the Oak Ridge National Laboratory. Kelton and his colleagues are particularly eager to see what the new instrument will tell them about glass transition, “the deepest and most interesting unsolved problem in solid-state research.”