Structure formation in binary mixtures of surfactants: vesicle opening-up to bicelles and octopus-like micelles

Abstract

Micelle formation in binary mixtures of surfactants is studied using a coarse-grained molecular simulation. When a vesicle composed of lipid and detergent types of molecules is ruptured, a disk-shaped micelle, the bicelle, is typically formed. It is found that cup-shaped vesicles and bicelles connected with worm-like micelles are also formed depending on the surfactant ratio and critical micelle concentration. The obtained octopus shape of micelles agrees with those observed in the reported cryo-TEM images (S. Jain and F. S. Bates, Macromolecules, 2004, 37, 1511). Two types of connection structures between the worm-like micelles and the bicelles are revealed.