Distinct dynamical and structural properties of a core-softened fluid when confined between fluctuating and fixed walls

TL;DR

This study investigates how the mobility of confining walls influences the structural and dynamical behavior of a core-softened fluid, revealing significant differences between fixed and fluctuating boundary conditions.

Contribution

It introduces a comparative analysis of fluid behavior under fixed versus fluctuating confining walls using a two-length scale potential model.

Findings

Fluid properties are strongly affected by wall mobility.

Distinct behaviors are explained via the two-length scale potential.

Fluctuating walls alter the anomalous behavior of the fluid.

Abstract

We study the influence of mobility of the confining media in the structural and dynamical properties of a core-softened fluid under confinement. The fluid is modeled using a two-length scale potential, which reproduces in bulk the anomalous behavior observed in water. We perform simulations in the $NVT$ ensemble with fixed flat walls and in the $NpT$ ensemble using a fluctuating wall control of pressure to study how the fluid behavior is affected by fixed and non-fixed walls. Our results indicate that the fluid dynamical and structural properties are strongly affected by the wall mobility. The distinct observed behavior are explained in the framework of the two length scale potential.