Metal separation using polypyrroles containing chelating agents
Electrochemically controlled transport of copper and iron across composite membranes containing polypyrrole (PPy) doped with either 8-hydroxyquinoline-5-sulfonic acid (HQS) or 2,9-dimethyl-4. 7-diphenyl-l, 1 O-phenanthrolinedisulfonic acid (BCS) is described. The flux of copper across composite Pl'yIBCS membranes was greater than that for iron. and almost 50 times greater than the largest value previously reported for copper transport across a conducting polymer membrane. Composite membranes containing PPy/HQS allwed transport of copper ions but proved completely impermeable to iron transport.