Phase behavior of didecylpyrrolidium bromide in aqueous solution

The phase behavior of a double chained pyrrolidinium surfactant, didecylpyrrolidium bromide (DC10PB), in aqueous solution was studied. Polarized optical microscopy (POM), cryogenic-transmission electron microscope (cryo-TEM) and small-angle X-ray scattering (SAXS) measurements were employed to investigate the properties of the structures formed. With increasing DC10PB concentration, isotropic solution phase, vesicle phase, and lamellar liquid crystal (LLC) phase are presented in aqueous solution. The structural parameters of the LLC phase were calculated from SAXS patterns, which show the change in detail as a function of the amount of DC10PB. The rheological measurements reveal that the viscoelasticity increases with DC10PB concentration because of the densely packing of the surfactant molecules.