Ion-Exchange Reaction of Cs+ Selective Layered .GAMMA.-Titanium and .GAMMA.-Zirconium Phosphates
| Accession number;04A0747309 |
| Title;Ion-Exchange Reaction of Cs+ Selective Layered .GAMMA.-Titanium and .GAMMA.-Zirconium Phosphates |
| Author;SUZUKI N(Showa Pharmaceutical Univ., Tokyo) IGARASHI M(Showa Pharmaceutical Univ., Tokyo) SUZUKI H(Showa Pharmaceutical Univ., Tokyo) ITOH M(Showa Pharmaceutical Univ., Tokyo) KOMATSU Y(Kanazawa Inst. Technol., Oshikawa) KANZAKI Y(Showa Pharmaceutical Univ., Tokyo) |
Journal Title;Bull Chem Soc Jpn
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Journal Code:G0450A
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ISSN:0009-2673
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VOL.77;NO.10;PAGE.1829-1833(2004)
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| Figure&Table&Reference;FIG.4, TBL.4, REF.12 |
| Pub. Country;Japan |
| Language;English |
| Abstract;The H+/MA+ ion-exchange reaction of layered .GAMMA.-titanium and .GAMMA.-zirconium phosphates, MT(HPO4)2 nH2O, was examined, where MA is an alkali metal and MT is Ti or Zr. They showed remarkably high ion-exchange selectivity for Cs+ and Rb+ in acidic media. The selectivity for Na+ was rather low, and Li+ exchange hardly occurred. The H+ ion exchange of both .GAMMA.-phosphates with Cs+ and Rb+ apparently occurred in two steps. These ion-exchange reactions occurred first at a pH value of around 2.0 to form a monobasic structure, MTMAH(PO4)2 nH2O, accompanied by dehydration of the water of crystallization. The second step occurred at a pH around 8.0 to form a dibasic structure, MT(MAPO4)2 nH2O, the interlayer space of both .GAMMA.-phosphates swelled again. The lattice of crystals gradually collapsed corresponding to further progress of the ion-exchange reaction with Cs+ and Rb+, and the amorphous phase finally appeared. According to 133Cs NMR study, Cs+ was found to be rather restricted. The results were compared with those of layered synthetic mica. The high Cs+ and Rb+ selectivity was ascribed to the dehydration property and strong interactions of these ions with the host lamella layers. The high selectivity of two .GAMMA.-phosphates for Cs+ in acidic media suggested a potentiality as promising materials for the recovery from radioactive waste. The interfering effect of coexisting Fe2+ was scarcely observed upon Cs+ exchange, and was even positive due to the prevention of lattice coagulation. (author abst.) |
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