Thermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures

TitleThermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures
Publication TypeJournal Article
Year of Publication2009
AuthorsVaknin D, Bu W, Sung J, Jeon Y, Kim D
Journal TitleJournal of Physics-Condensed Matter
Volume21
Pages115105
Date Published03/18
ISBN Number0953-8984
Accession NumberISI:000263677300007
Keywordsfluctuations, fluid interfaces, liquid-vapor interface, scattering, surfaces, thickness, x-ray reflectivity
Abstract

The density profiles of liquid/vapor interfaces of water-alcohol (methanol, ethanol and propanol) mixtures were studied by surface-sensitive synchrotron x-ray scattering techniques. X-ray reflectivity and diffuse scattering measurements, from the pure and mixed liquids, were analyzed in the framework of capillary wave theory to address the characteristic length scales of the intrinsic roughness and the shortest capillary wavelength (alternatively, the upper wavevector cutoff in capillary wave theory). Our results establish that the intrinsic roughness is dominated by average interatomic distances. The extracted effective upper wavevector cutoff indicates capillary wave theory breaks down at distances of the order of bulk correlation lengths.

URL<Go to ISI>://000263677300007
DOI10.1088/0953-8984/21/11/115105