Capillary waves on an asymmetric liquid film of pentane on water.
Surface light-scattering measurements have been carried out on thin asymmetric films of pentane on water. We vary the film thickness ? over a wide range (10(-9) m < ? < 10(-5) m). Compared with the ripplons wavelength 1/q, thick films of pentane (? ? 1/q) display the same power spectrum as a pure pentane-vapor interface: a single peak. When thinning the film down to ? approximately 1/q, hydrodynamic coupling between the layers of the interface is revealed by the appearance of a second peak beside the first one. We describe the thickness dependence of the two coupled modes through variations of the positions, the widths, and the amplitudes of both peaks.
Fenistein
D
D
Wegdam
G H
GH
Meyer
W V
WV
Mann
J A
JA