The effect of water structure and surface charge correlations on the hydration force acting between model hydrophilic surfaces

Abstract

We performed molecular dynamics simulations to study the interactions between model hydrophilic plates. Our plates were made of a layer of carbon atoms distributed on a hexagonal lattice. Although neutral, the plates carry an equal amount of positive and negative charges to represent physical dipoles. Using thermodynamic perturbation theory we calculated the potential of mean force (PMF) acting between the plates as a function of the distance between these plates. We also studied the effect of charge correlation on the PMF. We calculated the contribution of the solvent water into the PMF and compared this contribution with the predictions of continuum theory. The orientational structure of water between the plates was investigated to understand the effect of molecular structure of water on the properties of the PMF.

Acknowledgement

This work was supported by the National Science Foundation under grant number MCB-0615469. MLB would like to thank Professor G. Manning for valuable discussions.