The Interface in Demixed Colloid–Polymer Dispersions

In Chaps. 3 and 4, the focus was on theory and experiments related to the phase behaviour of mixtures containing colloidal spheres and nonadsorbing polymers. As we have seen, when the polymer coils are sufficiently large relative to the colloidal spheres, a colloidal gas–liquid (fluid–fluid) phase separation may occur. The two phases that appear differ in composition. One phase is a dilute colloidal fluid (a colloidal ‘gas’) dispersed in a concentrated polymer solution. This phase coexists with a concentrated colloidal fluid (a colloidal ‘liquid’) dispersed in a dilute polymer solution.