Facilitated transport of organics of biological interest II. Selective transport of organic acids by macrocyclic fixed site complexant membranes

Fixed-site heteropolysiloxane membranes containing polytopic grafted macroc yclic receptors were synthesized and used in separations of organic acids o f biological importance (aspartic acid, succinic acid, tartaric acid). They presented promising transport fluxes and selectivities of the aspartic acid from a mixture of the three cited above acids, as function of operati ng conditions. The cooperative transport was based on new multiple molecula r recognition principles and dependent on a membrane potential generated by the co-transport of protons. Thus these membranes simulated biological org anic compound transport in cell membranes. (C) 2000 Elsevier Science B.V. A ll rights reserved.