Title | Molecular view of the isothermal transformation of a stable glass to a liquid |
Publication Type | Journal Article |
Year of Publication | 2008 |
Authors | Swallen, S. F., K. L. Kearns, S. Satija, K. Traynor, R. J. McMahon, and M. D. Ediger |
Journal | Journal of Chemical Physics |
Volume | 128 |
Start Page | 214514 |
ISBN Number | 0021-9606 |
Accession Number | WOS:000256527500033 |
Keywords | AROMATIC HYDROCARBONS, CRYSTALS, FICKIAN DIFFUSION, FILMS, INTERFACE, NAPHTHYLBENZENE, PHYSICAL PROPERTIES, TRANSITION |
Abstract | We have used neutron reflectivity to measure translational motion on the nanometer length scale in exceptionally stable glasses of tris(naphthylbenzene). These glasses are prepared by vapor deposition onto a substrate held somewhat below the glass transition temperature (T(g)=342 K). When the most stable samples are annealed at 345 K, no translational motion is observed on the 12 nm length scale for over 10 000 s and full mixing requires more than 60 000 s. For comparison, the equilibrium supercooled liquid mixes in 1000 s at this temperature and on this length scale. These measurements provide insight into the mechanism by which a stable glass transforms into a liquid. "Melting" of the stable glass appears to occur by the growth of liquid regions into the surrounding glassy matrix, perhaps by a surface-initiated growth process. At 345 K, translational motion in the stable glass is at least 100 times slower than motion in the supercooled liquid. (C) 2008 American Institute of Physics. |
DOI | 10.1063/1.2919570 |
Alternate Journal | J. Chem. Phys. |