Naslov
The effect of mechanical treatment of zirconium(IV) hydroxide on its thermal behaviour

Autori
Štefanic, Goran ; Popović, Stanko ; Musić, Svetozar

Izvornik
Thermochimica Acta (0040-6031) 259 (1995), 2; 225-234

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
DSC ; FTIR ; TGA ; XRD ; Zirconium hydroxide

Sažetak
Precipitated zirconium(IV) hydroxide was ball- milled at room temperature for 1, 3, 9, 35 and 60 h. The samples were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).DSC curves of the samples, obtained by ball- milling for 1, 3 and 9 h, showed two exothermic peaks due to crystallization of tetragonal ZrO2 as determined by XRD and FT-IR. These two exothermic peaks were ascribed to the heterogeneity of the zirconium(IV) hydroxide structure caused by ball- milling. The samples, obtained by ball-milling for 35 and 60 h, showed only one exothermic peak. Three important phenomena, as a consequence of the ball-milling of zirconium hydroxide, were observed: (a) dehydration, (b) an increase in the activation energy of the crystallization and (c) a decrease in the enthalpy of crystallization of t- ZrO2 from ball-milled zirconium hydroxide. The present study indicated that the process of crystallization oft -ZrO2 from zirconium(IV) hydroxide is more complex than a simple structural (topotactic) rearrangement.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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