γ-irradiation effects on kinetics and mechanism of the thermal decomposition of zinc acetate

The kinetics of the thermal decomposition of un-irradiated (pristine) and pre-gamma-irradiated dehydrated zinc acetate was studied in the temperature range (553-573 K) and in air using both isothermal and dynamic thermogravimetric techniques. The data were analyzed using various solid state reaction models. The integral method using the Coats-Redfern equation was applied in the dynamic data analysis. The results showed that the kinetics of isothermal decomposition of dehydrated zinc acetate was governed by a phase-boundary controlled reaction (R-2) while in non-isothermal (dynamic) decomposition the kinetic was controlled by a nucleation process. The activation energies of the main decomposition process for un-irradiated and pre-gamma-irradiated samples were calculated and the results of the isothermal and dynamic integral methods were compared and discussed. The changes in texture and crystal structure of the investigated zinc acetate by gamma-irradiation were studied using electron microscopy and X-ray diffraction techniques.