Abstract

Abstract: Ternary systems made of surfactant, oil and water display a variety of well-ordered nanostructured phases, and are therefore believed to be interesting scaffolding material. Here I will present the L3 phase, also known as “sponge phase”, with pore sizes in the range of ten nanometres. These are usually stable only within a narrow temperature and concentration range. However, our research group has shown that the sponge phase can be stabilized over a larger phase space by doping it with metal nanoparticle suspensions. We make and study sponge-phase samples doped with Au, Ag, and Pd aquasols and organosols. Remarkably, Pd-doped sponge phases are stable up to temperatures as high as 50 ºC. Polarised microscopy studies as well as small-angle and wide-angle X-ray scattering measurements (SAXS and WAXS ) confirm that the nanoparticles are indeed incorporated in the sponge phase membrane. Moreover, rheological measurements show that, unlike the undoped samples, metal-doped sponge phases exhibit reversible phase transitions under shear stress. The various factors that control the stability and optical properties of these metal-doped sponge phases are outlined and discussed.