Water confined in nanopores: spontaneous formation of microcavities

TL;DR

This study uses Molecular Dynamics simulations to reveal that water confined in nanometer-sized hydrophobic channels spontaneously forms non-spherical microcavities, influenced by vapor layer formation and pore geometry.

Contribution

It demonstrates the spontaneous formation and shape characteristics of microcavities in nanoconfined water, linking cavitation to vapor layer formation as predicted by theory.

Findings

Localized cavities form in water at ~2.0 nm pore diameter

Cavities are non-spherical and near the confining wall

Cavitation correlates with vapor layer formation

Abstract

Molecular Dynamics simulations of water confined in nanometer sized, hydrophobic channels show that water forms localized cavities for pore diameter ~ 2.0 nm. The cavities present non-spherical shape and lay preferentially adjacent to the confining wall inducing a peculiar form to the liquid exposed surface. The regime of localized cavitation appears to be correlated with the formation of a vapor layer, as predicted by the Lum-Chandler-Weeks theory, implying partial filling of the pore.