Thermal-swing Extraction of Cadmium(II) by Thermosensitive Polymer Gel Crosslinked with Encapsulating Hexadentate Ligand

Thermal-swing extraction of CdII 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. CdII was extracted in the gel swollen at 5 °C and released from the gel shrunken at 40 °C. The difference in the distribution ratios of CdII between these temperatures was more than 30 times.