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

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.