Kinetic analysis for the non-isothermal decomposition of un-irradiated and ?-irradiated zirconium acetylacetonate

• Published in: Progress in reaction kinetics and mechanism Vol. 37; no. 1; pp. 59 - 75
• Main Authors: Al-Otaibi, A M, Al-Wassil, A I, Siddiqui, MRH, Mahfouz, R M
• Format: Journal Article
• Language: English
• Published: London Sage Publications Ltd 01.01.2012
• Subjects: Decomposition; Diffraction; Melting; Nanoparticles; Reaction kinetics; Transmission electron microscopy; Zirconium; Zirconium dioxide
• ISSN: 1468-6783; 1471-406X
• DOI: 10.3184/146867811X13095343745013

Kinetic studies for the non-isothermal decomposition of un-irradiated and ?-irradiated zirconium acetylacetonate, Zr(acac)4, with 103 KGy total ?-ray dose were carried out in static air. The results show that decomposition proceeds through multiple steps and ends with the formation of ZrO2 as a final solid residue without any significant changes in the thermal behaviour between un-irradiated and ?-irradiated samples of Zr(acac)4. The non-isothermal data for both un-irradiated and ?-irradiated Zr(acac)4 were analysed using both model-free and model-fitting approaches. Irregular variation of Ea with ? indicates a complex decomposition mechanism involving multi-step processes including melting, sublimation and degradation and more than one model could be suggested to explain the results. Calcination of Zr(acac)4 at 600 °C for five hours led to the formation of ZrO2 monodispersed nanoparticles, characterised by X-ray diffraction, FT-IR, SEM and TEM. This is the first example of preparing ZrO2 nanoparticles by solid state thermal decomposition of Zr(acac)4.