화학공학소재연구정보센터
Journal of Electroanalytical Chemistry, Vol.451, No.1-2, 29-37, 1998
Electrochemical extraction of heavy metal ions assisted by cyclic thioether ligands
The ion transfer characteristics of a series of divalent heavy metal species have been studied at the polarised water\1,2- dichloroethane interface. Both direct and cyclic thioether assisted transfer mechanisms have been investigated by voltammetric measurements. Half-wave potentials and Gibbs energies for direct ion transfer processes follow the order, Pb2+ < Cd2+ < Zn2+ < Cu2+. A series of hydrophobic cyclic thioether ligands, i.e. 1,4,7,10-tetrathiacyclododecane (TTCD), 1,5,9,13-tetrathiacyclohexadecane (TTCH), 1,4,7-trithiacyclodecane (TriTCD), 1,4,7-trithiacyclononane (TTCN) and trithiane (TT) have been investigated as heavy metal ion ionophores. Lead(II) ion transfer assisted by TTCD and TTCN is shown to behave in an electrochemically reversible manner. Cadmium(TI) also shows reversible assisted transfer with the TTCN ligand. The respective stoichiometry and the association constants in 1,2-dichloroethane have been determined for these reversible systems.