Di(2-ethylhexyl)isobutyramide (D2EHIBA) has been evaluated as a carrier for U/Th separation in supported liquid membrane. Microporous PTFE membrane was used as the polymeric support for the transport studies of uranium from a feed containing nitric acid. Effect of experimental parameters, viz. role of diluent, carrier concentration, feed acidity, metal ion concentrations on U/Th transport has been investigated. A model describing the transport mechanism has been proposed. Negligible transport of metal ions, such as Cs(l), Sr(II), Fe(III) and Eu(III) was observed under the optimised conditions. Reusability of membrane was also investigated. (c) 2005 Elsevier B.V. All rights reserved.