Attractive double-layer forces between neutral hydrophobic and neutral hydrophilic surfaces

TL;DR

This paper demonstrates ion-specific attractive double-layer forces between neutral hydrophobic and hydrophilic surfaces in salt solutions, using a generalized Poisson-Boltzmann approach informed by molecular dynamics simulations.

Contribution

It introduces a novel theoretical framework combining Poisson-Boltzmann equations with MD-derived parameters to study neutral surface interactions.

Findings

Ion-specific attraction observed between hydrophobic and hydrophilic surfaces.

Theoretical predictions align with molecular dynamics simulation results.

Highlights the importance of ion effects in surface interactions.

Abstract

The interaction between surface patches of proteins with different surface properties has a vital role to play driving conformational changes of proteins in different salt solutions. We demonstrate the existence of ion-specific attractive double-layer forces between neutral hydrophobic and hydrophilic surfaces in the presence of certain salt solutions. This is done by solving a generalized Poisson-Boltzmann equation for two unequal surfaces. In the calculations we utilize parameterized ion-surface-potentials and dielectric-constant-profiles deduced from recent non-primitive-model molecular dynamics (MD) simulations that account partially for molecular structure and hydration effects.