Energy Component Analysis of Electric Field-Induced Shape Change in Water Nanodroplets

Abstract

We present a comprehensive classical molecular dynamics study of water nanodroplets under the influence of an externally applied electric field. Our simulations cover a wide range of droplet sizes and electric field strengths, which allows for a thorough exploration of the structural and energetic behavior of nanodroplets in the presence of an external electric field. Our analysis reveals the molecular-level mechanism behind the shape extension of a nanodroplet from a spheroid to a highly prolate ellipsoid as the propensity of the water dipoles to align with the electric field while simultaneously restructuring to minimize the dipole–dipole interaction energy. We also develop a quantitative theory that describes the energetic landscape for the nanodroplet shape extension process and allows predictions of the nanodroplet behavior based on its initial size and the strength of the applied field.