# Interface dynamics of microscopic cavities in water

## TL;DR

This paper develops an analytical model for the interface motion of nanometer-sized cavities in water, validated by molecular dynamics simulations, revealing how curvature effects influence collapse dynamics at the nanoscale.

## Contribution

It introduces a modified Rayleigh-Plesset equation incorporating curvature effects, bridging continuum and molecular dynamics descriptions of cavity collapse in water.

## Key findings

- Quantitative agreement between analytical and molecular dynamics results.
- Collapse velocity scales with surface tension over viscosity.
- Curvature accelerates collapse below 1 nm scale.

## Abstract

An analytical description of the interface motion of a collapsing nanometer-sized spherical cavity in water is presented by a modification of the Rayleigh-Plesset equation in conjunction with explicit solvent molecular dynamics simulations. Quantitative agreement is found between the two approaches for the time-dependent cavity radius $R(t)$ at different solvent conditions while in the continuum picture the solvent viscosity has to be corrected for curvature effects. The typical magnitude of the interface or collapse velocity is found to be given by the ratio of surface tension and fluid viscosity, $v\simeq\gamma/\eta$, while the curvature correction accelerates collapse dynamics on length scales below the equilibrium crossover scales ($\sim$1nm). The study offers a starting point for an efficient implicit modeling of water dynamics in aqueous nanoassembly and protein systems in nonequilibrium.