Macrocyclic carriers in supported liquid membranes

✍ Scribed by Wilma F. van Straaten-Nijenhuis; Feike de Jong; David N. Reinhoudt

• Book ID: 104589526
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 840 KB
• Volume: 112
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19931120602

✦ Synopsis

Abstract

Macrocyclic receptor molecules can be designed to selectively bind a variety of host molecules, including metal cations and neutral molecules. This property can be uniquely exploited in separation processes, by using these compounds as carriers in transport through liquid membranes.

The various types of liquid membrane systems are briefly discussed, and the attractive features of the supported (by a microporous polymer film) liquid membrane (SLM) are explained. The mechanical stability of the SLMs is dependent on several factors, including the type of polymer support, membrane solvent, and hydrophobicity of the carrier used.

The rates and selectivity of transport are discussed in terms of membrane geometry, membrane solvent type, structure and concentration of the carrier, and the type and concentration of cations, and anions in both the source and receiving phases. Existing mathematical models in which these parameters have been incorporated, are compared with experimental data. Apart from a concentration gradient of the metal cation over the membrane, other driving forces, such as anion concentration, proton counter‐transport and redox‐active transport, are discussed.