New Method for Theoretical Spinodals Corresponding to Ternary Solutions with an Amphiphile Component

A new method is presented to obtain a theoretical spinodal for ternary solutions with an amphiphile component. This method uses a generalized Wheeler-Widom model representing the ternary solution, and considers local fitting conditions with the experimental binodal, imposing that the theoretical binodal must pass through a point on the experimental binodal, and also that the slope of the theoretical binodal has to be as close as possible to the slope of the representative experimental binodal. Using the previously specified fitting conditions, the corresponding spinodal is derived. The results are in agreement with an older method of local fitting between the generalized Wheeler-Widom model and the experimental data, where the fitting condition implied the coincidence of the theoretical tie-line with the experimental tie-line.