Constitutive equations for Ca2+-alginate gels

Constitutive equations accounting for the coupling between chemical and mechanical phenomena are developed for the Ca2+ alginate gel from the framework of thermodynamics of irreversible processes with internal variables. The development of the model is based on the Gibbs-Duhem relation and kinetic relations acting on generalized non-equilibrium forces. The constitutive equations are then compared to mechanical data obtained from uniaxial compressive tests at different velocities. A good agreement is observed between model and data. Furthermore, the model is able to predict the evolution of the mechanical response when the initial quantity of crosslinked Ca2+ ions varies. (C) 2011 Elsevier Ltd. All rights reserved.