Interaction between two overall neutral charged microscopically patterned surfaces

TL;DR

This study investigates the interactions between heterogeneously charged surfaces in an electrolyte, using classical DFT and Monte Carlo simulations, revealing how domain size, charge, and concentration affect osmotic pressure and force sensitivity.

Contribution

It validates classical DFT against Monte Carlo simulations for charged surface interactions and explores parameter effects difficult to simulate directly.

Findings

Force curves are more sensitive to domain size in asymmetric configurations.

Bulk electrolyte concentration has a weak influence on force curves.

Validated cDFT accurately predicts interaction behaviors.

Abstract

We study the interaction between heterogeneously charged surfaces in an electrolyte solution by employing classical Density Functional Theory (cDFT) and Monte Carlo simulations. We observe a consistent behavior between cDFT and Monte Carlo simulations regarding force curves and two-dimensional density profiles. Armed with the validated cDFT, we explore the system's behavior under parameters challenging to simulate directly .Our findings include impacts of domain size, domain charge, domain charge configuration, and bulk electrolyte concentration on the osmotic pressure. Remarkably, the force curve is more sensitive to the domain size for asymmetric configuration than symmetry configuration; the bulk concentration weakly influences the force curve independent of the system configurations.