Journal of Membrane Science, Vol.258, No.1-2, 5-7, 2005
Affinity membranes for the extraction of Cd2+ metal ions by facilitated transport ensured by a new thiacalix[4]arene complexing agent incorporated in supported liquid membranes (SLM)
A thiacalix[4]arene dissolved in NPOE for incorporation in a supported liquid membrane, is shown to ensure a transmembrane transport flux of Cd2+ ions with an order of magnitude higher than that obtained with a very lipophilic carrier such as Lasalocide A, according to a mechanism of active facilitated transport (coupled to a pH gradient). Liquid-liquid (water-NPOE) extraction experiments confirmed the good affinity of the thiacalix[4]arene for the Cd2+ ions at the interface between an aqueous medium of pH = 8 and NPOE organic phase, as well as its almost complete release in water when the pH of the aqueous phase is changed to acid. (c) 2005 Elsevier B.V. All rights reserved.