Metal-ion uptake and release by reversed micelles: Comparison of liquid membranes with direct liquid—liquid contact and with interfacial semipermeable membranes

Abstract Micelles and microemulsion droplets have recently been shown to behave as mobile carriers in liquid membrane transport processes; this property has potential applications in drug delivery systems, hydrometallurgy, separation of biochemicals, etc. Different experimental devices can be used to measure the flux of transported solutes. We propose here a new type of cell in which semipermeable membranes are placed at the interface between two liquid phases and we compare the advantages of this cell with those of a previous one involving direct liquid—liquid contact. The influence of different parameters (volume of liquid membrane, speed of the circulating pumps, etc…) on the transport of potassium picrate by sodium bis-(2-ethylhexyl) sulfosuccinate (AOT)/H 2 O reversed micelles in decane, is examined and the results are shown to be consistent with a model of facilitated diffusion. Finally, the transport of nickel salts by AOT/H 2 O or tetraethylene glycoldodecylether (C 12 EO 4 )-hexanol/H 2 O reversed micelles in decane demonstrates that the transfer mechanisms at the liquid—liquid interfaces are not significantly affected by the presence of the semipermeable membranes.