SELF-DIFFUSION OF BARIUM AND CESIUM CATIONS IN NEUTRON-IRRADIATED AND GAMMA-IRRADIATED HIGH-SILICA ZEOLITES AND BORON-ZEOTYPES

Kinetics of Cs+ and Ba2+ self-exchange in neutron- and gamma-irradiated high-silica zeolites and borosilicates (boron-zeotypes) has been studied. Neutron irradiation of barium- and caesium-loaded high-silica zeolites and their boron-zeotypes caused a slight decrease in their exchange capacity. Diffusion coefficients and activation energies were measured at temperatures between 298 and 333 K and thermodynamic parameters DELTAS* and DELTAG* were calculated. In the boron-zeotype materials, the magnitude of (n, alpha) damage was increased by the use of framework boron containing B-10. The zeolites used were synthesized according to published methods and were characterized by XRD, FTi.r., SEM, t.g./d.t.g., and d.s.c. techniques.