Authors:José Geraldo de P. Espínola, Evandro P. S. Martins, Franklin P. Aguiar, Haryane R. M. Silva, M. G. Fonseca, L. N. H. Arakaki, and Ercules E. S. Teotônio
after the dissolution of the HNO3 complex, using a GBC, model 908 AA device for spectroscopy. The chlorine content was calculated using the Volhard method after resolution of the HNO 3 complex as well. Thermaldecomposition was performed using a
Authors:Ashok K. Vishwakarma and Prasanna S. Ghalsasi
[ 15 ]. In case of B , DTA shows endothermic peak at 212.1 °C due to thermaldecomposition. At this temperature it loses one mole of 4-chloro anilinium chloride along with 4-chloro aniline. After the loses of organic ammonium chloride along with amine
Authors:L. Szirtes, J. Megyeri, L. Riess, and E. Kuzmann
The thermal decomposition of zirconium molybdate, tungstate and arsenate were investigated. The total mass losses of the investigated materials were 12.5, 11 and 8.5%, respectively. Despite having different crystal dimensions and structure the thermal decomposition of the samples takes place in a similar way. During heating two main endothermic processes with mass loss were observed. At the end of the thermal decomposition, oxides of the original materials were observed. The mentioned mass losses originate partly from the crystal water loss of the materials. The calculated crystal water content in the original molecule was 1.3 and 1 mole/molecule unit, respectively. Furthermore, for zirconium arsenate, a sublimation process was recorded above 960 K.
The effect of60C0-gamma radiation on the kinetic parameters of the thermal decomposition of potassium bromate crystals has been investigated. Radiation did not modify the mechanism of thermal decomposition reaction, but resulted in a decrease in activation energy and frequency factor with a rate which is large at small doses and decreases at higher doses. The results showed that the increase in the concentration of decomposition nuclei tends to be more important than the increase in the porous character of the solid.
Authors:Zhou Bao-xue, Zhong Wei-ke, Zou Li-zhuang, and Wang Xiao-ling
Barium(II) tetraphenylborate, Ba(Bph4))2·4H2O was prepared, and its decomposition mechanism was studied by means of TG and DTA. The products of thermal decomposition were examined by means of gas chromatography and chemical methods. A kinetic analysis of the first stage of thermal decomposition was made on the basis of TG and DTG curves and kinetic parameters were obtained from an analysis of the TG and DTG curves using integral and differential methods. The most probable kinetic function was suggested by comparison of kinetic parameters. A mathematical expression was derived for the kinetic compensation effect.
Authors:V. Logvinenko, T. Chingina, N. Sokolova, and P. Semyannikov
The thermal decomposition of several lanthanide salts Ln(CF3COO)33H2O (Ln=La, Gd, Tb) was studied under quasi-equilibrium conditions and under linear heating. According to mass spectral data, H2O is the single product of thermal decomposition up to 120-140C. Thermogravimetric data were processed with 'Netzsch Thermokinetics'
computer program. Kinetics parameters of the first decomposition step (as the simple dehydration process, not complicated
by the water hydrolysis with the liberation or the decomposition of the organic ligand) were calculated.
The results of comparative thermal analysis (TG-DTG-DTA-DSC) of the thermal decomposition of hexamminecobalt(III) chloride
in air atmosphere are reported. The kinetics and mechanism of the thermal decomposition, the process enthalpy and the variation
in specific thermal capacity of the solid product reaction with temperature were determined.
The thermal decomposition of hydroxylammonium neodymium sulfate dihydrate has been investigated by simultaneous thermogravimetry and differential thermal analysis. Chemical analysis, X-ray powder spectra and infrared spectroscopy have been employed to characterize the intermediates and the final product. The thermal decomposition can be described by the sequence (NH3OH)Nd(SO4)2·2H2O→(NH3OH)Nd(SO4)2→ → NH4Nd3(SO4)5→Nd2(SO4)3. The first and the second reactions overlap, but the last one is well separated from the first two.
Authors:Z. D. Zivkovic, N. Milosavljevic, M. Grotowska, and W. Wojciechowski
In this paper the results of comparative thermal analysis TG-DTG-DTA-DSC for the thermal decomposition process of [Cr(NH3)6]Cl3 in air atmosphere are given. The kinetics and mechanism of this complex thermal decomposition, process enthalpy as the changes of specific thermal capacity of solid products reaction with temperature were determined.
An investigation was carried out on the kinetics of thermal decomposition of plumbo-jarosite. The kinetic models of dissociation
of the compounds in the ore were identified. The results of the kinetic studies and the mechanism of the process are discussed.
The thermal decomposition of plumbo-jarosite occurs in three stages: the first up to 763, the second up to 1023 and the third
up to 1223 K, the corresponding activation energy values being 62.2, 60.3 and 98.0 kJ mol–1 , respectively.