Papers by Keyword: Thermal Dehydration

Abstract: Thermal dehydration kinetics of aluminum sulfate hydrates was studied with TG/DTA under static open air environment. It was found that the thermal dehydration of the aluminum sulfate hydrates was a two-stage process. The first stage happened in the temperature range from 90 to 300°C with 13 water loss. The second stage happened in the temperature range from 300 to 380 °C with 2 water loss. Activation energy and former factor of each staged were obtained by regression the TG/DTA data with 19 differential and integral functions based on non-isothermal Achar method as well as Coats-Redfern method. The result indicated that the mechanism for the first stage dehydration was the proliferation of three-dimensional, spherical symmetry, 3D, D3, slow-α-t curve, n = 2, reaction is reaction 2. The mechanism of the second stage dehydration was random nucleation and subsequent growth, A3, S-shaped α-t curve, n=1/3, m = 3, reaction is reaction 1/3. Identified that the most likely mechanism of Al2(SO4)3•15H2O dehydration is 2 and 1/3 reactions two process.

Abstract: The advantages and uniqueness of the Inorganic modification of the Sol-Gel method have already been described. Homogeneous nano-composites as well as some exotic glasses, complex-metal-oxides systems with little glass-forming ability, can be produced by this method. Thus, the obtained materials are characterized by a complex structure that leads to the wide variety of physical and chemical properties. Zirconia-containing materials are of utmost interest because of the mechanical toughness and chemical resistance provided by the presence of ZrO2. In the present work, we report on unusual structural peculiarities of the Zr-O, two types of Zr-Ge-O systems (with Zr>Ge and Zr

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