Electrofreezing of Liquid Water at Ambient Conditions

TL;DR

This study demonstrates that applying moderate electric fields to water at room temperature can induce a transition to a ferroelectric glassy phase, providing the first evidence of electrofreezing under ambient conditions.

Contribution

It provides the first computational evidence of electrofreezing of water at ambient conditions and characterizes a new ferroelectric amorphous phase induced by electric fields.

Findings

Electrofreezing occurs after ~150 ps at 0.10-0.15 V/Å electric fields.

A new ferroelectric glassy water phase (f-GW) is identified.

Transition involves a continuous change to a disordered, frozen dynamical state.

Abstract

Water is routinely exposed to external electric fields (EFs). Whether, e.g., at physiological conditions, in contact with biological systems, or at the interface of polar surfaces in countless technological and industrial settings, water responds to EFs on the order of a few V/{\AA} in a manner that is still under intense investigation. Dating back to the $19^{th}$ century, the possibility of solidifying water upon applying an EF instead of adjusting temperature and pressure -- a process known as electrofreezing -- is an alluring promise that has canalized major efforts since, with uncertain outcomes. In this work, we perform long \emph{ab initio} molecular dynamics simulations \textcolor{black}{of water at ambient conditions exposed at EFs of different intensities. While the response of single water molecules is almost instantaneous, the cooperativity of the hydrogen bonds induces slower reorganizations that can be captured by dividing the trajectories in disjoint time windows and by performing analysis on each of them separately. Upon adopting this approach, we find} that EFs of $0.10\leq$EFs$\leq0.15$~V/{\AA} induce electrofreezing \textcolor{black}{occurring after $\sim150$~ps. We observe a continuous transition to a disordered state characterized by frozen dynamical properties, damped oscillations, lower energy, and enhanced local structural properties. Therefore, we ascribe this state to} a new ferroelectric amorphous phase, which we term f-GW (ferroelectric glassy water). Our work represents the first evidence of electrofreezing of liquid water at ambient conditions and therefore impacts several fields, from \textcolor{black}{fundamental chemical physics to} biology \textcolor{black}{and} catalysis.