Chemical Engineering and Processing, Vol.47, No.7, 1044-1052, 2008
Functional organic-inorganic hybrid membranes
The membrane selectivity may be induced either by carrier molecules or by transmembrane channels. From the mechanistic point of view, we use carriers which self-assemble in functional aggregates which would present combined (hybrid) intermediate features between the former carrier-monomers and the resulted channel-forming superstructures. Thus, we therefore studied the membrane transport properties in hybrid dense solid or in mesoporous membranes of such supramolecular organic-inorganic hybrid systems resulted by the dynamic self-assembly of the hydrogen-bonded urea-crown ethers, aromatic aminoacids and nucleosides. This review presents a survey of different methods and processes which can be used for the generation of hybrid supramolecular membranes. Then, basic working principles of molecular recognition-type and self-organized membranes are provided in order to better understand requirements in material design for the generation of functional ionic-conduction pathways. Finally, these systems have been employed successfully to design new dynamic-site complexant membranes immobilized in a mesoporous hybrid nanospace. (C) 2007 Elsevier B.V. All rights reserved.