The paper investigates the validity of steady-state approximation for the case of constant rate thermal analysis experiments. It is shown that the approximation holds for the experiments run with a controlled rate of either the decomposition of the compound, or the production of gas.
Authors:Xuehang Wu, Wenwei Wu, Kaiwen Zhou, Xuemin Cui, and Sen Liao
-DSC technique. Non-isothermalkinetics of the thermal decomposition of precursor was interpreted by Flynm–Wall–Ozawa (FWO) method [ 18 , 19 ]. The kinetic ( E a , ln A , mechanism) parameters of the thermal decomposition of precursor MgFe 2 (C 2 O 4 ) 3 ·6H 2
Authors:Zhipeng Chen, Qian Chai, Sen Liao, Yu He, Wenwei Wu, and Bin Li
2 O using TG–DTA technique. Non-isothermalkinetics of the decomposition process of α-LiZnPO 4 ·H 2 O was interpreted by a modified method [ 24 – 29 ], the apparent activation energy E a was obtained from iterative procedure [ 29 ], the most
Authors:Qing-Ping Hu, Xue-Gui Cui, and Zhao-He Yang
The thermal decomposition of the mixed-ligand complex of iron(III) with 2-[(o-hydroxy benzylidene)amino] phenol and pyridine-[Fe2O(OC6H4CH=NC6H4O)2(C5H5N)4]·2H2O and its non-isothermal kinetics were studied by TG and DTG techniques. The non-isothermal kinetic data were analyzed and the kinetic parameters for the first and second steps of the thermal decomposition were evaluated by two different methods, the Achar and Coats-Redfern methods. Steps 1 and 2 are both second-order chemical reactions. Their kinetic equations can be expressed as: dα/dt=Ae−E/RT(1-α)2
Authors:N. Sbirrazzuoli, L. Vincent, J. Bouillard, and L. Elégant
In the case of a complex mechanism of two parallel independent reactions, peak maximum evolution methods and model-fitting
methods give only a mean value of the kinetic parameters, while isoconversional methods are useful to describe the complexity
of the mechanism. Isothermal and non-isothermal isoconversional methods can be used to elucidate the kinetics of the process.
Nevertheless, isothermal isoconversional methods can be limited by restrictions on the temperature regions experimentally
available because of duration times or detection limits.
The method suggested by several authors for determining the mechanism of solid-phase transformations by linearizing the function Ing(α) vs. 1/T is more correct for a hyperbolic temperature change than for a linear temperature change. In the latter case, the method yields reliable results only under the condition that the relationship Ing(α)/T2vs. 1/T is linear. The well-known Horowitz-Metzger method is essentially suited for processing thermokinetic curves obtained under hyperbolic heating or cooling.