# Experimental Evidence for the Pore Size Dependence of Elastic Properties in a Liquid Adsorbate Confined to Nanopores

## TL;DR

This study experimentally confirms that the elasticity of liquid argon increases in smaller nanopores, matching theoretical predictions.

## Contribution

First experimental confirmation of the predicted pore size dependence of elastic moduli in nanoconfined adsorbates.

## Key findings

- The modulus of liquid argon increases linearly with the inverse of the pore radius.
- Results align with theoretical predictions about nanoconfinement effects on adsorbate elasticity.

## Abstract

The elasticity of adsorbates is relevant for many applications
of porous materials. Theoretical studies predict a pronounced increase
of elastic moduli for adsorbates under nanoconfinement, but an experimental
confirmation is still missing. Here we present an ultrasonic study
on the longitudinal modulus β
Ar,ads
of liquid argon in porous glass samples with different
pore radii between 1.8 and 12.8 nm. The analysis of the measured moduli
of empty, β0, and filled samples, β, reveals
that the modulus of the adsorbate, β
Ar,ads
, increases linearly with the inverse
pore radius, 1/r

P
, as
predicted by theory.