Spontaneous vesicle formation in aqueous solutions of linear alkylbenzenesulfonate and a linear alkylbenzenesulfonate/nonionic surfactant mixture upon addition of divalent ions

Spontaneous vesicle formation is found in 1% aqueous solutions of linear alkylbenzenesulfonate (LAS) and mixtures of LAS and the nonionic surfactant, C-n-(N-methyl) glucose amide (MEGA), upon addition of a mixture of Ca2+/Mg2+ (2:1 molar ratio), Cryo-transmission electron microscopy(cryo-TEM) has been used to image the colloidal structures. A spherical micelleto-vesicle transition occurs with increasing divalent ion concentration, However, thread-like micelles are absent from this transition. Many of the vesicles are exceptionally small, having a diameter less than 25 nm. (C) 1996 Academic Press, Inc.