Shear thinning in deeply supercooled melts

Equiaxed dendritic solidification in supercooled melts

The growth of equiaxed dendrites from a pure supercooled melt is examined. We propose modifications to the classical Ivantsov theory that allow for consideration of multiple interacting dendrites. The modified theory reveals the existence of a steady-state dendritic solidification mode in a frame of reference moving with the dendrite tip. This regime should be valid from the onset of nucleation...

Observation of the density minimum in deeply supercooled confined water

Small angle neutron scattering (SANS) is used to measure the density of heavy water contained in 1D cylindrical pores of mesoporous silica material MCM-41-S-15, with pores of diameter of 15 1 Å. In these pores the homogenous nucleation process of bulk water at 235 K does not occur, and the liquid can be supercooled down to at least 160 K. The analysis of SANS data allows us to determine the abs...

Stringlike correlated motion in the dynamics of supercooled polymer melts

Shear Viscosity and Diffusion in Supercooled Liquids

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 fluct...

On the Bauschinger effect in supercooled melts under shear: results from mode coupling theory and molecular dynamics simulations.

We study the nonlinear rheology of a glass-forming binary mixture under the reversal of shear flow using molecular dynamics simulations and a schematic model of the mode-coupling theory of the glass transition (MCT). Memory effects lead to a history-dependent response, as exemplified by the vanishing of a stress-overshoot phenomenon in the stress-strain curves of the sheared liquid, and a chang...