A temperature-programmed time-of-flight secondary ion mass spectroscopy study of intermixing of amorphous ethanol and heavy-water films at 15-200 K.
On the basis of time-of-flight secondary ion mass spectrometry, the intermolecular interactions of amorphous ethanol and heavy-water films have been investigated in terms of the translational molecular diffusion, hydrogen-bond reorganization, and isotope scrambling. The morphology of the ethanol film (heavy-water film) changes at 120 K (165 K), and the isotope scrambling takes place between the ethanol and heavy-water molecules above 140 K. The intermixing of the layered binary films of ethanol and heavy water is induced at 120 K as a consequence of the increased mobility of the ethanol molecules but the mixing is incomplete at the molecular level. The complete mixing occurs above 140-150 K provided that the highly mobile water molecules emerge. It is concluded that the viscous liquid phase evolves above the conventional glass-transition temperatures (97 and 136 K for ethanol and heavy water, respectively), which is followed by the drastic morphological change (120 and 165 K) as a consequence of the increased fluidity of the films.
Souda
Ryutaro
R
Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.