Synthesis and Characterization of a Novel Metal Phosphonate–Zirconium (IV) Hydroxy Ethylidene Diphosphonate–and its Application in Separation of Metal Ions

Abstract

A novel hybrid ion exchange material, zirconium hydroxy ethylidene diphosphonate [ZrHEDP] of the class of tetravalent metal acid (tma) salt has been synthesized by sol-gel method. The material has been characterized for elemental analysis (ICP-AES), thermal analysis (TGA, DSC), FT-IR and X-ray diffraction studies. Chemical resistivity of the material in various media (acids, bases and organic solvents) have been assessed. ZrHEDP has been further probed for its utility as an ion exchanger. The Na+ ion exchange capacity (i.e.c.) has been determined and effect of heating on i.e.c. studied. The distribution behaviour of ZrHEDP towards several metal ions has been studied in different electrolyte media/concentrations. Based on the distribution studies a few binary metal ion separations have been achieved.