New two macrocyclic compounds using as carriers of liquid emulsion menbrame, have been synthesized. These reuslts provide evidance for the usefulness of the theory in designing the systems. The efficiency of selective transport for heavy metal ions have been discussed from the membrane systems that make use of SCN^- I^- , CN^- and Cl^- ion as co-anions in source phase and make use of S_2O_3^2- and P_2O_7^4- ion as receiving phase, respectively. The transport, rate of M(Ⅱ) was highest when a maximum amount of the M(Ⅱ) in the source phase was present as Cd(SCN)_2([SCN^-]=0.40M, Hg(SCN)_2([SCN^-]=0.40M) and Pb(CN)_2([CN^-]=0.40M). The Cd(Ⅱ) and Pb(Ⅱ) over each competitive cations were well transprted with 0.3M-S_2O_3^2- and 0.3M-P20_7^4 , respectively in the receiving phase. Results of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsion system. First one must effective extraction of the M^n+ into the toluene systems. The effectiveness of this extraction is the greatest if logK for M^n+-macrocycle interaction is large and if the macrocycle is very insoluble in the aqueous phase. Second, the ratio of the logK values for M^n+-receiving phase (S_2O_3^2- or P_2O_7^4-) to M^n+-macrocycle (L_1 or L_2) interaction must be large enough to ensure quantitative stripping of M^n+(Cd^2+, Hg^2+ or Pb^2+) at the toluene receiving phase interface. L_1(3.5-benzo-10,13,18,21-tetraoxa-1,7,diazabicyclo(8,5,5) eicosan) forms a stable Cd^2+ and Pb^2+ complexes and L_1 is very insoluble in water and its Cd2^+ and Pb^2+ complex is considerably less stable than Cd^2+-(S_2O_3)_2^2- and Pb^2+-P_2O_7^4- complexe is On the other hand, the stability of the Hg^2+-L_1 complex exceed that of the Hg^2+-(S_2O_3)_2^2- and Hg^2+-P_2O_7^4- , and the distribution coefficient of L_2(5,8,15,18,23,26-hexaoxa-1,12- diazabicyclo-(10,8,8) octacosane) is much smaller than that of L_1. Therefore, the partitioning of L_2 is favored by the aqueous receiving phase, and little heavy metal ions transport is seen despite the large logK for Hg^2+-L_1 and M^n+(Cd^2+, Pb^2+ and Hg^2+)-L_2 interactions.

• Oh Jin Jung | 정오진