Edmond–Ogston model (original) (raw)

The Edmond–Ogston model is a thermodynamic model proposed by Elizabeth Edmond and Alexander George Ogston in 1968 to describe phase separation of two-component polymer mixtures in a common solvent. At the core of the model is an expression for the Helmholtz free energy , where represents the slope of the binodal and spinodal in the critical point. Its value can be obtained by solving a third order polynomial in , , which can be done analytically using Cardano's method and choosing the solution for which both and are positive. The model is closely related to the Flory–Huggins model.