Anomalies in a waterlike model confined between plates

TL;DR

This study uses molecular dynamics to explore how a waterlike model behaves under confinement between hydrophobic plates, revealing shifts in anomalous density and diffusion behaviors and layer formation transitions.

Contribution

It provides new insights into the effects of confinement on waterlike anomalies and layer structures, extending understanding beyond bulk behavior.

Findings

Maximum density and diffusion temperatures decrease under confinement.

Layer formation depends on the distance between plates, with a critical threshold.

Central layers remain liquid while contact layers crystallize in three-layer systems.

Abstract

Using molecular dynamic simulations we study a waterlike model confined between two fixed hydrophobic plates. The system is tested for density, diffusion and structural anomalous behavior and compared with the bulk results. Within the range of confining distances we had explored we observe that in the pressure-temperature phase diagram the temperature of maximum density (TMD line), the temperature of maximum and minimum diffusion occur at lower temperatures when compared with the bulk values. For distances between the two layers below a certain threshold ,$d\le d_c$, only two layers of particles are formed, for $d\ge d_c$ three or more layers are formed. In the case of three layers the central layer stays liquid while the contact layers crystallize. This result is in agreement with simulations for atomistic models.