Mechanism of ion exchange in zirconium phosphates. 31. Thermodynamics of alkali metal ion exchange on amorphous zirconium phosphate Academic Article uri icon

abstract

  • The thermodynamics of alkali metal ion exchange on amorphous zirconium phosphate have been studied over a wide loading range. Selectivities for the amorphous exchanger were initially Cs+ > Rb+ > K+ > Na+ > Li+. This series changed with loading, until complete reversals to the series Li+ > Na+ > K+ > Rb+ > Cs+ was observed at high loads. The sequences observed including those at intermediate loads agree very closely with those predicted by Eisenman. The polynary Na+-K+-Cs+-H+ exchange system has also been studied. Selectivities observed in this system agree very well with those predicted from the binary systems. Enthalpy and entropy changes for the exchange reactions are discussed and explained in terms of a model in which the size of the cavities in amorphous zirconium phosphate is not uniform, but varies over a range of values. © 1981 American Chemical Society.

author list (cited authors)

  • Kullberg, L., & Clearfield, A.

citation count

  • 30

publication date

  • May 1981