  Despite intense research, methods for controlling soft matter's spontaneous
self-assembly in-to well-defined layers remain a significant challenge. We
observed ion-induced structural disconti-nuities of phospholipid vesicles that
can be exploited for controlled self-assembly of soft materials. We used
dynamic light scattering, zeta-potential measurement, cryo-electron microscopy,
small-angle X-ray, and small-angle neutron scattering. All the experimental
observations indicate that de-clining solvent quality and increasing osmotic
pressure direct lipids to expel preferentially to the inner compartment. Upon
reaching a critical concentration, excess lipids can form a new bilayer. This
spontaneous self-assembly process causes simultaneous shrinkage of the aqueous
core and expansion of the vesicle. This approach opens an intriguing path for
controlling the self-assembly of bioinspired colloids, which can also serve as
a vehicle to control the polymerization of multilayer polymeric systems.
