STABILITY-CRITERIA FOR AN ELASTIC MIXTURE

The conditions that a system is stable relative to the formation of new domains differing in composition from the original homogeneous phase can be deduced from the extremum principle of thermodynamics. According to this principle the internal energy should assume its minimum value at constancy of entropy and volume. Starting from the complete set of variables describing an anisotropic phase the stability criteria for an elastic mixture are derived following a procedure proposed by L. Tisza. The conditions are applied to a gel coexisting with the pure solvent.