Atomic scale insights into NaCl nucleation in nanoconfined environments

Abstract

In this work we examine the nucleation from NaCl aqueous solutions within nano-confined environments, employing enhanced sampling molecular dynamics simulations integrated with machine learning-derived reaction coordinates. Through our simulations, we successfully induce phase transitions between solid, liquid, and a hydrated phase, typically observed at lower temperatures in bulk environments. Interestingly, nano-confinement serves to stabilize the solid phase and elevate melting points. Our simulations explain these findings by underscoring the significant role of water, alongside ion aggregation and subtle, anistropic dielectric behavior, in driving nucleation within nano-constrained environments. This letter thus provides a framework for sampling, analyzing and understanding nucleation processes under nano-confinement.