Thermal-swing extraction of cadmium(II) by thermosensitive polymer gel crosslinked with encapsulating hexadentate ligand

Thermal-swing extraction of Cd-II with a thermosensitive gel, poly(N-isopropylacrylamide) (NIPA) crosslinked with an encapsulating ligand, N,N,N',N'-tetrakis(4-propenyloxy-2-pyridylmethyl)ethylenediamine TPPEN), was examined. Cd-II was extracted in the gel swollen at 5 degrees C and released from the gel shrunken at 40 degrees C. The difference in the distribution ratios of Cd-II between these temperatures was more than 30 times.