Anomalous dynamics of confined water at low hydration

TL;DR

This study uses computer simulations to reveal that water molecules confined in silica pores exhibit anomalous sublinear diffusion at low hydration levels, similar to water near proteins, highlighting unique confined water dynamics.

Contribution

It provides new insights into the anomalous diffusion behavior of confined water molecules at low hydration, linking it to residence time decay.

Findings

Water shows sublinear diffusion in silica pores at low hydration.

Anomalous diffusion is connected to residence time decay.

Behavior resembles water at contact with proteins.

Abstract

The mobility of water molecules confined in a silica pore is studied by computer simulation in the low hydration regime, where most of the molecules reside close to the hydrophilic substrate. A layer analysis of the single particle dynamics of these molecules shows an anomalous diffusion with a sublinear behaviour at long time. This behaviour is strictly connected to the long time decay of the residence time distribution analogously to water at contact with proteins.