# Hydrogen Polarity of Interfacial Water Regulates Heterogeneous Ice Nucleation

## TL;DR

This study uses molecular dynamics simulations to reveal how hydrogen polarity in interfacial water influences heterogeneous ice nucleation, highlighting the role of hydrogen polarization in modulating nucleation barriers.

## Contribution

It introduces a new MD method to analyze ice nucleation and demonstrates that hydrogen polarity in interfacial water significantly affects ice formation on substrates.

## Key findings

- Hydrogen polarization increases surface tension at the ice-water interface.
- Hydrogen disorder in interfacial water facilitates ice nucleation.
- Surface tension modulation by hydrogen polarity impacts nucleation free energy barrier.

## Abstract

Using all-atomic molecular dynamics(MD) simulations, we show that various substrates could induce interfacial water (IW) to form the same ice-like oxygen lattice but different hydrogen polarity order, and regulate the heterogeneous ice nucleation on the IW. We develop an efficient MD method to probe the shape, structure of ice nuclei and the corresponding supercooling temperatures. We find that the polarization of hydrogens in IW increases the surface tension between the ice nucleus and the IW, thus lifts the free energy barrier of heterogeneous ice nucleation. The results show that not only the oxygen lattice order but the hydrogen disorder of IW on substrates are required to effectively facilitate the freezing of atop water.