Multiscale Modeling of Polymer Gels-Chemo-Electric Model versus Discrete Element Model

TL;DR

This paper compares multiscale models, including a coupled multi-field and a discrete element approach, for simulating chemically stimulated polymer gels, highlighting their applicability in engineering contexts.

Contribution

It introduces and compares two advanced modeling approaches for polymer gels under chemical stimuli, enhancing understanding of their behavior across different scales.

Findings

The coupled multi-field model captures large deformation behavior.

The discrete element model provides detailed particle-level insights.

Both models are evaluated for practical engineering applications.

Abstract

Polyelectrolyte gels are a very attractive class of actuation materials with remarkable electronic and mechanical properties with a great similarity to biological contractile tissues. They consist of a polymer network with ionizable groups and a liquid phase with mobile ions. Absorption and delivery of solvent lead to a large change of volume. This mechanism can be triggered by chemical (change of salt concentration or pH of solution surrounding the gel), electrical, thermal or optical stimuli. Due to this capability, these gels can be used as actuators for technical applications, where large swelling and shrinkage is desired. In the present work chemically stimulated polymer gels in a solution bath are investigated. To adequately describe the different complicated phenomena occurring in these gels, they can be modeled on different scales. Therefore, models based on the statistical theory and porous media theory, as well as a coupled multi-field model and a discrete element formulation are derived and employed. In this paper, the coupled multi-field model and the discrete element model for chemical stimulation of a polymer gel film with and without domain deformation are employed. Based on these results, the presented formulations are compared and conclusions on their applicability in engineering practice are finally drawn.