Carrier mediated transport of uranium(VI) through track-etch immobilized liquid membranes containing TBP as a carrier

Immobilized liquid membranes (ILM) offer numerous advantages over other separation techniques including high selectivity, the ability to 'pump' against a concentration gradient, high fluxes relative to solid membranes, low capital and operating costs, and the ability to use even expensive extragents. High performance membranes can be easily made by immobilizing a membrane solvent containing an efficient and suitable carrier in a thin porous support. By judicious selection of the membrane solvent, ionopore and support, ILM's can have both high selectivity and high permeant fluxes. However, the wide spread use of this technique is at present partly limited by the scarce availability of desirable hydrophobic membrane supports. This prompted us to initiate a programme for the preparation and characterization of fission track-etched thin MAKRAFOL membranes (MF) and their subsequent testing as the flat solid support for ILM. Quinn et al. have already indicated the feasibility of the production of such supports by a track-etch method to provide membranes with uniform parallel pores. Tri-n-butyl phosphate (TBP), in dodecane, a commercial extractant for U(VI) was selected as the mobile carrier. Chemical stability of the MF membranes against aqueous source and receiving phases and membrane solvents was also evaluated. (author). 1 fig., 1 tab