Stringlike Cooperative Motion in a Supercooled Liquid

Stringlike clusters and cooperative interlayer permeation in smectic liquid crystals formed by colloidal rods.

Using simulations of hard rods in smectic-A states, we find stringlike clusters of up to 10 interlayer rods exhibiting dynamic cooperativity. We also find non-gaussian diffusion and heterogeneous dynamics due to the equilibrium periodic smectic density profiles, which give rise to permanent barriers for layer-to-layer diffusion. This relaxation behavior is surprisingly similar to that of nonequ...

Polymer-specific effects of bulk relaxation and stringlike correlated motion in the dynamics of supercooled polymer melt

Stringlike correlated motion in the dynamics of supercooled polymer melts

Experimental observations of non-Gaussian behavior and stringlike cooperative dynamics in concentrated quasi-two-dimensional colloidal liquids.

We report, from direct observation of particle trajectories as a function of time, the presence of stringlike cooperative motion in a quasi-two-dimensional liquid. We have used digital video microscopy to study the equilibrium dynamics of suspensions of sterically stabilized uncharged poly(methylmethacrylate) spheres confined in a thin glass cell. Our experiments reveal the existence, in semidi...

Examination of dynamic facilitation in molecular dynamics simulations of glass-forming liquids.

Using data from molecular dynamics computer simulations of the one-component Dzugutov liquid and of BKS silica in metastable equilibrium supercooled states, we examine ideas introduced by Garrahan and Chandler (GC) in their dynamic facilitation (DF) model of the glass transition. Utilizing a recently introduced measure of DF, we find that DF is important for particle motion in both the supercoo...