Thermodynamics and hydrodynamics of chemical gels II. Gels in binary solvents

(Received 23 March 1992, accepted in final form 5 June 1992)

Abstract
We have developed a framework of the thermodynamics and hydrodynamics of chemically crosslinked gels in a binary miscible solvent. This work is an extension of a previous one on gels in a single solvent [Sekimoto K., J. Phys. II France 1 (1991) 19]. Introduction of a composition degree of freedom of the solvent leads to both thermodynamic chemo-mechanical coupling an kinematical cross-coupling between permeation and mutual diffusion of solvent. Using an appropriate thermodynamic potential for gel in a solvent bath, we also discussed (local) equilibrium boundary conditions at the surface of a gel and at the interface between a shrunken phase domain and a swollen phase domain in a gel undergoing a volume phase transition.