PREPARATION OF A PHASE DIAGRAM FOR COACERVATION

The objective of this study was to develop a method of preparing a phase diagram of coacervated systems using physical measurements instead of chemical analyses. The per cent weight-in-weight concentration of three-component solutions of micro and macromolecules was related to the refractive indexes and specific gravities of the solutions by an algebraic equation. The composition of both phases of several different coacervated systems was determined by using the derived equations. By making accurate quantitative dilutions, it was also possible to determine the composition of solutions the specific gravity of which did not remain linear because of a high concentration of electrolyte. This study indicates that the points needed for plotting a phase diagram (including tie lines) of three-component systems can quickly and accurately be determined by using measurements of specific gravities and refractive indexes.