Stabilizing\nEffect of PS‑<i>b</i>‑PMMA Diblock Copolymers\nin PS/PMMA-Based THF-in-THF Emulsions

We\nhave investigated the common solvent-based emulsion composed\nof polystyrene (PS) and poly(methyl methacrylate) (PMMA) solutions\nin tetrahydrofuran in the presence of PS-<i>b</i>-PMMA diblock\ncopolymers. The stabilization effect of the diblock was determined\nvisually and by confocal laser scanning microscopy at various phase\nvolume fractions, concentrations, and compositions of the copolymer.\nThe behavior of PS-<i>b</i>-PMMA in each homopolymer solution\nwas studied with static and dynamic light scattering. The copolymer\nformed micelles above a critical homopolymer concentration. Light\nscattering measurements showed that small amounts of the other homopolymer\nadded to the micelle solution entered the micelles spontaneously,\nsuggesting that the observed emulsion stability is caused by the diblock\ncopolymer laminar layer formation covering the surface of the dispersed\ndroplets.