1991 Volume 7 Issue Supple Pages 607-610
The voltammogram, VITTM, is introduced for the transfer of an ion, iz, from one aqueous solution, W1, to the other aqueous solution, W2, through a membrane, M, of organic solution (Org). The voltammogram is considerably different from that for the transfer of iz at the W/Org interface, VITIES, as follows; (1) The potential window observed in VITTM is about the twice of that in VITIES. (2) The slope of a reversible ion transfer wave in VITTM is much smaller than that in VITIES. (3) The potential region where the ion transfer wave appears in VITTM is difficult to expect, though that in VITIES can be estimated from the transfer energy of the transferring ion. In order to clarify the characteristics of VITTM, the relation between VITTM and VITIESs at W1/M and M/W2 interfaces has been investigated. Comparing the potential difference between W1 and W2, ΔV1W1-W2, at a definite current, I, in VITTM with those at W1/M and M/W2 interfaces, ΔVW1/M and ΔVM/W2, at I in VITIES, ΔVW1-W2 is found to be the sum of ΔVW1/M and ΔVM/W2, which suggests that ΔVW1-M2 and ΔWM/W2 may change depending on the ion transfer reaction at the W1/M and M/W2 interfaces even if ΔVW1-W2 is controlled at constant. The relation holds even with such a thin membrane as tetrafluoroethylene resin membrane of 48μm thick. Thepossibility of the separation of ions by the electrolysis under an applied ΔVW1-W2 is discussed based on the above-mentioned relation.
