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arXiv · 0904.2412

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

David Vaknin·Wei Bu·Jaeho Sung·Yoonnam Jeon·Doseok Kim
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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 characteristics length-scales of the intrinsic roughness and the shortest capillary-wavelength (alternatively, the upper wave-vector cutoff in capillary wave theory). Our results establish that the intrinsic roughness is dominated by average interatomic distances. The extracted effective upper wave-vector cutoff indicates capillary wave theory breaks-down at distances on order of bulk correlation lengths.

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David Vaknin, Wei Bu, Jaeho Sung, Yoonnam Jeon, Doseok Kim. 2009-04-15. Thermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures. https://doi.org/10.1088/0953-8984%2F21%2F11%2F115105

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