Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik
Doi
Abstract
We present a formulation of the free boundary problem for a hydrogel
that accounts for the interfacial free energy and finite strain due to the
large deformation of the polymer network during solvent transport across the
free boundary. For the geometry of an initially dry layer fixed at a rigid
substrate, our model predicts a phase transition when a critical value of the
solvent concentration has been reached near the free boundary. A
one-dimensional case study shows that depending on the flux rate at the free
boundary an initial saturation front is followed by spinodal decomposition of
the hydrogel and the formation of an interfacial front that moves through the
layer. Moreover, increasing the shear modulus of the elastic network delays
or even suppresses phase separation