It is proposed to use, electron microscopy, light, X-ray and neutron scattering, and other measurements to discover and characterize a menagerie of novel microstructures in synthetic and biological mixed surfactant systems. These structures offer excellent opportunities to: (1) enlarge the realm of surfactant solution microstructure from the limits of simple micelles and lamellar phases to include equilibrium vesicles and gels, (2) quantitiatively test theories of surfactant self-assembly, and (3) allow the development of new materials with important scientific and technological applications. This to date has led to the hypothesis that mixing micelle forming, single-tailed anionic and cationic surfactants lead to mixed bilayers with low bending constants; these low bilayer bending constants are then responsible for the observed structures and phase behavior. The work under this proposal is designed to (1) directly test this hypothesis by measuring elastic constants as a function of composition and (2) develop new materials based on low ending modulus bilayers such as polymer-surfactant gels. The idea that novel properties emerge from the exchange of fluorocarbon for hydrocarbon surfactant in catanionic mixtures will be explored. These assemblies will be used to guide synthesis of higher order structures. Work in this area will explore synthesis of controlled permeability vesicles by polymerization of catanionic vesicles.
