Vesicle gels—phase behaviour and process of formation

Phase behaviour and properties of a system composed of an anionic surfactant and a medium-chain alcohol as cosurfactant has been investigated for various different counterions. As a function of cosurfactant content pronounced differences are observed for the phase behaviour while the unilamellar vesicle gels formed at high octanol content are remarkably similar. Evidently this vesicle gel is energetically so strongly stabilised that here the counterion has only a minor effect. Furthermore, the kinetics of vesicle formation has been studied for the addition of various salts. Formation of the vesicle gel becomes faster with increasing ionic strength and even more so the stronger the counterion binds to the charged amphipilic interface.