Stable vesicle formation through intra- and inter-chain aggregation of poly[sodium N-(11-acrylamidoundecanoyl)-l-valinate] in aqueous solution

The vesicle-forming surfactant, sodium N-(11-acrylamidoundecanoyl)-l-valinate was polymerized to obtain corresponding polysoap. Light scattering and fluorescence probe techniques were used to characterize the polysoap. Fluorescence probe studies suggested that the polymer forms intra-chain as well as inter-chain aggregates. The microenvironment of the aggregates was studied by fluorescence measurements using 1-anilinonaphthalene, pyrene, and 1,6-diphenylhexatriene (DPH) as probe molecules. Fluorescence anisotropy studies by use of DPH have indicated a high local viscosity of the aggregates formed by the polysoap in water. The pH-induced change of the aggregate structure has been studied. The phase transition temperature of the polysoap was determined from temperature dependence of fluorescence anisotropy of DPH. Dynamic light scattering measurements were performed to determine the mean size of the aggregates. Transmission electron micrographs revealed closed vesicles in water.