Distinguishing deformation mechanisms in elastocapillary experiments

TL;DR

This study investigates deformation mechanisms in soft polyvinylsiloxane gel threads immersed in liquids, demonstrating that capillarity, buoyancy, and swelling can produce comparable effects, and presents a model aligning with the Young-Dupré equation.

Contribution

The paper introduces a comprehensive model that accounts for multiple deformation mechanisms in elastocapillary experiments, validating force laws at the contact line without additional tangential forces.

Findings

Deformations from capillarity, buoyancy, and swelling are comparable in magnitude.

The model accurately explains observed data across different liquids.

Measured forces align with the Young-Dupré equation.

Abstract

Soft materials are known to deform due to a variety of mechanisms, including capillarity, buoyancy, and swelling. In this paper, we present experiments on polyvinylsiloxane gel threads partially-immersed in three liquids with different solubility, wettability, and swellability. Our results demonstrate that deformations due to capillarity, buoyancy, and swelling can be of similar magnitude as such threads come to static equilibrium. To account for all three effects being present in a single system, we derive a model capable of explaining the observed data and use it to determine the force law at the three-phase contact line. The results show that the measured forces are consistent with the expected Young-Dupr\'e equation, and do not require the inclusion of a tangential contact line force.