Proton-driven cation transport through polyamic acid membranes incorporating crown ether moiety

✍ Scribed by H. Sakamoto; K. Kimura; T. Shono

• Book ID: 103072812
• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 365 KB
• Volume: 22
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(86)90101-1

✦ Synopsis

Proton-driven cation transport against cation concentration gradient has been investigated using films of polyamic acid 18-crown-6 (1) and polyamide 18-crown-6 (3)/polyamic acid (5) mixtures as the polymeric membrane. Both membrane systems containing the crown ethers were found to act as efficient alkali metal ion pumps. The ion-transportability of the polyamic acid 18-crown-6 membrane decreased in the order K + > Cs + > Na + > Li +, which is reflected in the cation-complexing ability of the 18-crown-6 moiety. The transport selectivity, however, was varied remarkably by the combined use of polyvinylpyrrolidone with (1) and, therefore, by the resulting increase in hydrophilicity of the membrane. The ion-selectivity in the transport through mixed membranes of (3) and ( ) was also dependent on the membrane composition. For the proton-driven cation transport two mechanisms are proposed; in one of the transport mechanisms, the carboxylic group cooperates with the crown ether moiety and in the other the carboxylic group participates independently.