Low-frequency elastic behavior of a supercooled liquidY. Chushkin1, C. Caronna1, 2 and A. Madsen1
1 European Synchrotron Radiation Facility - B.P. 220, F-38043 Grenoble, France
2 Department of Physical and Astronomical Sciences - via Archirafi 36, I-90123, Palermo, Italy
received 18 March 2008; accepted in final form 10 June 2008; published August 2008
published online 16 July 2008
By X-ray photon correlation spectroscopy we quantify the influence of elasticity and viscosity on the capillary wave (CW) surface dynamics of a supercooled liquid. To fit the data a novel model combining Maxwell-Debye and Voigt-Kelvin viscoelasticity is derived yielding a saturation of relaxation rates at high q as well as an offset in the CW dispersion relation. Diffuse X-ray scattering confirms the result and data taken on the surface of supercooled polypropylene glycol (PPG-4000) evidence a low-frequency elastic plateau of the storage modulus. A possible connection between the observed solid-like response and the supercooled state is discussed.
64.70.pm - Liquids.
61.05.cf - X-ray scattering (including small-angle scattering).
68.03.Kn - Dynamics (capillary waves).
© EPLA 2008