The versatility of polysorbate 80 (Tween 80) as an ionophore.

A number of experiments were performed to illustrate the unusual versatility of Polysorbate 80 (Tween 80) as an ionophore. New ions shown to be transported by it from and to water layers through a model membrane (CH2Cl2) include H3O+, Li+, Pb2+, Co2+, piperidinium ion, guanidinium ion, and Paraquat, while two complex ions resisted transport under the conditions used. "Reverse" transport of lipophilic guests (azobenzene, azulene, ferrocene) from and to organic solvents through water was also promoted by Tween 80, but C60 was not carried. Three water molecules were transported per molecule of KSCN by the Tween.