Electrochemical study of the ion transfer reaction at liquid/liquid interface and application to actinide separation

Transfer of actinide ions at the interface between two immiscible electrolyte solutions has been investigated by electrochemical method. In order to elucidate the transfer of actinide ions between two phases, a novel electrochemical method based on controlled-potential electrolysis has been developed. It was found that the method was applicable to the study of the transfer of such hydrophilic ions as transition metal ions which gave no appreciable current within the potential window in voltammetry or polarography at the interface. Controlled-potential electrolysis developed was applied to the transfer reactions of actinide ions such as UO22+ and Am3+ from aqueous solution to organic solution in the absence or presence of an ionophore facilitating the transfer. Gibbs energy for the transfer of actinide ion and a stability constant of the complex between an actinide ion and the ionophore in organic solution were determined. The controlled-potential electrolysis at the interface between two phases has feasibility as a method for electrolytic separation of actinide ions. (author)