The use of 1-alkylimidzoles for selective separation of zinc ions in the transport process across a polymeric inclusion membrane

The transport of Zn(II) ions from different aqueous nitrate(V) source feeding phases (cMe = 0.001 mol/dm3, pH 6.0) across polymer inclusion membranes (PIMs) doped with 1-alkylimidazole as an ion carrier was reported. Alkyl substituents in position 1 of imidazole ring have an effect on hydrophobic properties of the carriers and the initial flux of the transported metal ions. The membranes were characterized by an atomic force microscopy (AFM). The results show that the Zn(II) ions could effectively be separated from other transition metal cations such as Co(II) and Ni(II) from different equimolar ion mixtures. Also, the thermal stability of PIM doped with 1-decylimidazole was studied in replicate experiments. The highest separation coefficients for the Zn(II)/Co(II) and Zn(II)/Ni(II) systems, equal to 9.4 and 11.9 were recorded for the equimolar Zn(II)-Co(II)-Ni(II) mixture for 1-hexylimidazole as a carrier, while using 1-decylimidazole resulted in the highest values of initial flux of the Zn(II) ions transport across the polymeric membrane.