Non-simple flow behavior in a polar van der Waals liquid: structural relaxation under scope

TL;DR

This paper investigates how dipole interactions influence flow behavior in polar van der Waals liquids, revealing that such interactions can prevent simple liquid behavior and alter structural relaxation dynamics.

Contribution

It demonstrates that dipole interactions can couple with shear stress, modifying flow behavior and challenging the assumption of simple liquid dynamics in polar glass formers.

Findings

Dipole interactions couple with shear stress.

Flow behavior deviates from simple liquid models.

Intermolecular interactions influence structural relaxation.

Abstract

The non-exponential character of the structural relaxation is considered one of the hallmarks of the glassy dynamics and in this context, the singular shape observed by dielectric techniques has attracted the attention of the community for long time. Particularly, the exceptionally narrow dielectric response of polar glass formers has been attributed so far to dipolar cross correlations. Here we show that dipole interactions can couple to shear stress and modify the flow behavior preventing the occurrence of the simple liquid behavior. We discuss our findings in the general framework of the glassy dynamics and the role of intermolecular interactions.