A VARIATIONAL FORMULATION FOR COUPLED PHYSICOCHEMICAL FLOWS DURING FINITE DEFORMATIONS OF CHARGED POROUS-MEDIA

Polymer gels, hydrated biological tissues and other charged porous med ia may exhibit macroscopic coupling between solid deformations and int ernal fluid, chemical and electrical flows. In this manuscript, we dev elop a variationally motivated finite deformation-theory for describin g such coupled phenomena. The formulation combines mathematical descri ptions of the power balance associated with solid deformation and flui d and solute flows for an arbitrary number of solute species, and incl udes the macroscopic phenomenological coupling relations of nonequilib rium thermodynamics. Particular implementations of the theory are disc ussed for a charged,porous medium interacting with a binary electrolyt e and for the addition of a third, possibly charged solute species to such a system. This theoretical framework is suitable for modeling phy sicochemical interactions in a large class of hydrated porous media. ( C) 1998 Elsevier Science Ltd. All rights reserved.