| Research Abstract |
The ion transfer at an interface of aqueous (W) /Organic (Org) solution or W/Membrane (M) is controlled by the Galvani potential difference (DELTApsi) between the two phases. The objective of the present work was to develop a methodology for the highly sensitive ion separation utilizing the interface of which DELTA psi is controlled critically by the redox (electron transfer) reaction. The results are summarized in the following.
The electron transfer reactions at the interface between W containing ferricyanide, ferrocyanide, hydroxide ions or hydroquinone, etc. and Org containing ferrocene, tetrathiafulvalene, tetracyanoquinodimethane, etc. were investigated by the Voltammetry for the Charge Transfer at the Liquid/Liquid Interface (VCTLLI), and theoretical equations for the electron transfer were derived. The electron transfer is determined by the standard redox potential, concentration, diffusion coefficient, and activity of the redox species in both the phases. Combining the equation
… More
s for the electron transfer and those for the ion transfer, a theory for the interaction between ion and electron transfer reactions was proposed, and the theory was confirmed experimentally.
The effect of temperature on the ion transfer is mainly ascribable to the change in properties of solvents with the temperature, and that of coexisting salts is explained from both variations of water activity and the ion-pair formation in W with the salt concentrations. These effects are expected to be very effective to realize a highly selective separation of ions controlled by the electron transfer.
The oscillation of DELATpsi accompanied with the ion transfer not only influences the separation of ions but also relates profoundly to the excitation of living organisms. The first quantitative explanation on the process of the oscillation was proposed based on the investigation on the ion transfer and adsorption of ion-pair at the interface by VCTLLI and the consideration of the ionic equilibrium in both the phases. Less
|
