Structural arrest in dense star polymer solutions

TL;DR

This study investigates the dynamics of dense star polymer solutions using simulations and theory, revealing complex arrest phenomena and confirming mode-coupling theory predictions for glass transition behavior.

Contribution

It provides a comprehensive simulation and theoretical analysis of star polymer dynamics, highlighting the role of structure factors and mode-coupling theory in understanding glass transitions.

Findings

Isodiffusivity curves show minima and maxima with respect to density and functionality.

Mode-coupling theory accurately predicts the ideal glass transition line.

Disordered arrested states are explained by theoretical and simulation results.

Abstract

The dynamics of star polymers has been investigated via extensive Molecular- and Brownian Dynamics simulations for a large range of functionality $f$ and packing fraction $\eta$. The calculated isodiffusivity curves display both minima and maxima as a function of $\eta$ and minima as a function of $f$. Simulation results are compared with theoretical predictions based on different approximations for the structure factor. In particular, the ideal glass transition line predicted by mode-coupling theory is shown to exactly track the isodiffusivity curves, offering a theoretical understanding for the observation of disordered arrested states in star polymer solutions.