Extraction of the Solvation Structure on a Solid Plate from a force curve measured by Surface Force Apparatus in a hard-sphere fluid

TL;DR

This paper introduces a statistical mechanics-based method to derive the solvation structure near a surface from force measurements obtained via a surface force apparatus in a hard-sphere fluid, with promising accuracy at lower densities.

Contribution

It presents a novel transformation technique linking force curves to liquid density distributions, advancing the analysis of solvation structures from experimental force data.

Findings

Method works well in low-density solvents.

Accuracy improves with increased distance between probe surface and solvent spheres.

First demonstration on a rigid cylinder system in a hard-sphere fluid.

Abstract

We propose a method of transformation from a force curve obtained with a surface force apparatus (SFA) to a density distribution of a liquid near a surface. The method is based on the statistical mechanics of liquids. As a first step, we show the method for a rigid system in which two cylinders are immersed in a hard-sphere fluid as the force probes. We found that the method works well, especially in the lower density solvent. The accuracy of the transformed result increases as the distance between the circular surface of the cylinder and the solvent sphere increases.