Principles of Artificial Membrane Transport of Ions by Synthetic Ionophores

The general principles of ion transport across artificial membranes are examined with emphasis on carrier mediated transport across bulk liquid membranes. The theoretical predictions of a simple diffusion model are compared with key experimental example which are shown to be well correlated by such a model. The structural influences which control ion extraction and transport (ion binding sites, lipophilicity, coextracted ions) are examined. Theoretical and experimental criteria for detecting exceptions to the general behavior are outlined and examples are considered in the light of such criteria. The principles reviewed provide design criteria for the development of carriers and their successful exploitation in selective ion separations.