Kinetics of thermally induced swelling of hydrogels

TitleKinetics of thermally induced swelling of hydrogels
Publication TypeJournal Article
Year of Publication2006
AuthorsH Ji, H Mourad, E Fried, and J Dolbow
JournalInternational Journal of Solids and Structures
Start Page1878
Pagination1878 - 1907
Date Published04/2006

We present a continuum model for thermally induced volume transitions in stimulus-responsive hydrogels (SRHs). The framework views the transition as proceeding via the motion of a sharp interface separating swollen and collapsed phases of the underlying polymer network. In addition to bulk and interfacial force and energy balances, our model imposes an interfacial normal configurational force balance. To account for the large volume changes exhibited by SRHs during actuation, the governing equations are developed in the setting of finite-strain kinematics. The numerical approximations to the coupled thermomechanical equations are obtained with an extended finite element/level-set method. The solution strategy involves a non-standard operator split and a simplified version of the level-set update. A number of representative problems are considered to investigate the model and compare its predictions to experimental observations. In particular, we consider the thermally induced swelling of spherical and cylindrical specimens. The stability of the interface evolution is also examined. © 2005 Elsevier Ltd. All rights reserved.

Short TitleInternational Journal of Solids and Structures