Multivalent Metal Ion Induced Vesicle Aggregation in Aqueous Polyelectrolyte-surfactant System

The vesicle aggregation induced by multivalent metal ions in the mixed system of polyelectrolyte (hydrolyzed random copolymer of maleic anhydride-styrene, SMA)-surfactant (dodecyltriethylammonium bromide, DEAB) was investigated by transmission electron microscopy (TEM) observation and turbidity measurement. It was found that a small amount of Ca2+ (in the magnitude of 10−4 mol·L−1) could induce vesicle aggregation. Addition of EDTA can dissociate the vesicle aggregation. Further investigation suggested that the vesicle aggregation followed the salt-linkage mechanism.