PHASE-BEHAVIOR OF POLYMERS WITH CONCENTRATED DISPERSIONS OF SURFACTANTS

Mixtures of polymers and surfactants have been prepared at relatively high concentration and the regions of phase separation measured. The p olymers were both charged and uncharged, while the surfactants were no nionic. The separated phases were analyzed to obtain the tie lines for the two-phase region. The separated phases were either surfactant ric h or polymer rich. Higher molecular mass polymers induced separation a t lower concentration and the phase boundary did not depend strongly o n the persistence length of the polymer. This indicates that the main origin of the separation was depletion flocculation. A theory describi ng such phase separation has been developed and shows qualitative agre ement with the experimental results.