Microemulsion liquid membranes. I. Cobalt transport in a surfactant-dodecane system

Cobalt transport across supported microemulsion liquid membranes containing reversed micelles of dinonylnaphthalenesulfonic acid (HDNNS) was measured as a function of organic phase composition, aqueous phase composition, stirring rate and temperature. A microporous polypropylene film served as the membrane support. The membrane phase was characterized by interfacial tension and viscosity measurements. Stirring speed and temperature effects suggest that diffusion processes play a major role in the transfer of cobalt across the membrane. The experimental results at relatively low carrier concentration are explained by a membrane transport model involving counter-diffusion of HDNNS reversed micelles and metal-reversed micelle complexes.