Hydrophobic force a Casimir-like effect due to hydrogen bond fluctuations

TL;DR

This paper models the hydrophobic force as a Casimir-like effect caused by hydrogen bond fluctuations in confined water, using a lattice model and mean field theory, aligning well with simulations and experiments.

Contribution

It introduces a first-principles statistical mechanics model that explicitly links hydrophobic force to hydrogen bond fluctuations and long-range correlations.

Findings

Hydrophobic force arises from Casimir-like effects due to hydrogen bond fluctuations.

Model predictions agree with molecular dynamics simulations and experimental data.

Long-range orientational correlations significantly influence hydrophobic interactions.

Abstract

Hydrophobic force, interfacial tension, transverse density profile in confined water system are addressed from first principles of statistical mechanics in a lattice model for water. Using molecular mean field theory technique we deduce explicit expressions for each of the above mentioned phenomena and show that hydrophobic force is a manifestation of Casimir-like effect due to hydrogen bond fluctuations in confined water. It is largely influenced by the long range correlations of orientational fluctuations. All the computations are parameter-free and we compare favorably with results of molecular dynamics simulations and experiments.