Phospholipid membranes repulsion at nm-distances explained within a continuous water model

TL;DR

This paper demonstrates that a continuous water model can accurately predict the nanometer-scale repulsive forces between hydrophilic membranes, supporting the hydration hypothesis over entropic explanations.

Contribution

The study applies a phenomenological polar liquid theory to model membrane repulsion, providing quantitative agreement with experimental data and highlighting the role of water correlations.

Findings

Repulsive pressure between membranes is captured by the model.

Repulsion is largely temperature-independent.

Supports hydration hypothesis for membrane interactions.

Abstract

We apply recently developed phenomenological theory of polar liquids to calculate the repulsive pressure between two hydrophilic membranes at nm-distances. We find that the repulsion does show up in the model and the solution to the problem fits the published experimental data well both qualitatively and quantitatively. Moreover, we find that the repulsion is practically independent on temperature, and thus put some extra weight in favour of the so called hydration over entropic hypothesis for the membranes interactions explanation. The calculation is a good proof of concept example a continuous water model application to non-trivial interactions on -size bodies in water arising from long-range correlations between the water molecules.