Shear Viscosity and Diffusion in Supercooled Liquids
نویسنده
چکیده
Under normal liquid conditions (at equilibrium or when moderately super cooled), molecular rotational and translational diffusion adhere closely to the sim ple Stokes-Einstein-Debye hydrodynamic model. Deeply supercooled "fragile" liquids present a striking exception, with translational diffusion alone occurring up to 102 — 103 times "too fast". This anomaly rests upon the statistics of fluctuating local viscosity in the fragile glass-forming medium. The simplest version of this picture identifies large fluidized domains that spontaneously appear and disappear in a dynamically inert matrix. Plausible and self-consistent values characterizing these fluctuations are cited for orthoterphenyl (OTP) at its glass transition.
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تاریخ انتشار 2009