scholarly journals Thermal behavior and decomposition kinetics of rifampicin polymorphs under isothermal and non-isothermal conditions

2010 ◽  
Vol 46 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Ricardo Alves ◽  
Thaís Vitória da Silva Reis ◽  
Luis Carlos Cides da Silva ◽  
Silvia Storpírtis ◽  
Lucildes Pita Mercuri ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Melting Process ◽  
Decomposition Process ◽  
Stable Form ◽  
Thermal Decomposition Process ◽  
Mean Values ◽  
Conversion Level ◽  
Polymorphic Forms ◽  
Crystalline Forms

The thermal behavior of two polymorphic forms of rifampicin was studied by DSC and TG/DTG. The thermoanalytical results clearly showed the differences between the two crystalline forms. Polymorph I was the most thermally stable form, the DSC curve showed no fusion for this species and the thermal decomposition process occurred around 245 ºC. The DSC curve of polymorph II showed two consecutive events, an endothermic event (Tpeak = 193.9 ºC) and one exothermic event (Tpeak = 209.4 ºC), due to a melting process followed by recrystallization, which was attributed to the conversion of form II to form I. Isothermal and non-isothermal thermogravimetric methods were used to determine the kinetic parameters of the thermal decomposition process. For non-isothermal experiments, the activation energy (Ea) was derived from the plot of Log β vs 1/T, yielding values for polymorph form I and II of 154 and 123 kJ mol-1, respectively. In the isothermal experiments, the Ea was obtained from the plot of lnt vs 1/T at a constant conversion level. The mean values found for form I and form II were 137 and 144 kJ mol-1, respectively.

Electron paramagnetic resonance and microstructural insights into the thermal behavior of simonkolleite nanoplatelets

2020 ◽  
Vol 22 (17) ◽  
pp. 9503-9512
Author(s):  
Arpad Mihai Rostas ◽  
Andrei Cristian Kuncser ◽  
Daniela Ghica ◽  
Alexandra Palici ◽  
Valentin Adrian Maraloiu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Thermal Decomposition ◽  
Electron Paramagnetic Resonance ◽  
Thermal Behavior ◽  
Decomposition Process ◽  
Thermal Decomposition Process ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The thermal decomposition process of simonkolleite, at 500 °C was monitored by EPR and electron microscopy. The experimental data indicate that after an 1 h at 500 °C, three morphologies can be observed from the thermal decomposition of ZHC.

scholarly journals The Effect of Al Particles Size on the Thermal Behavior and Kinetics of Al-MnO2 Thermite System

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jia-xing Song ◽  
Tao Guo ◽  
Wen Ding ◽  
Miao Yao ◽  
Li Yang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Exothermic Reaction ◽  
Exothermic Peak ◽  
Decomposition Process ◽  
Particle Sizes ◽  
Ultrasonic Dispersion ◽  
Thermal Decomposition Process ◽  
Al Powder

Micron-MnO2 powder has unique thermal decomposition process compared with other metal oxides, and the different characteristics of components in thermite could affect the thermal performance of the whole system directly. In this work, the Al powder with different three particle sizes was combined with micron-MnO2 to prepare the Al-MnO2 thermite system, and the effect of Al powder particle sizes on the whole thermal behavior was studied. Firstly, the thermal decomposition process of micron-MnO2 and purity of Al powder are tested by TG-DSC. By using ultrasonic dispersion method, the fuel-rich thermite samples were prepared and characterized by SEM and TG-DSC at different heating rates. The Kissinger method was also employed to calculate the activation energy for the first exothermic peak. It was found that the thermal decomposition process of MnO2 in the thermite system can be significantly disturbed by different Al particles size. In other words, the effect of Al particle sizes on the thermite can be magnified due to the unique decomposition properties of micron-MnO2 instead of onset temperature of exothermic reaction changing simply. The activation energy of thermite system decreased with the reduction of Al particle sizes in micron-level, while in nanolevel the activation energy markedly increased. Finally, the possible reasons for phenomenon were discussed.

Corrosion Property of Container Using Hybrid Material for Thermal Decomposition Process of Sulfuric Acid

2021 ◽  
Author(s):  
Ikuo Ioka ◽  
Jin Iwatsuki ◽  
Yoshiro Kuriki ◽  
Daisuke Kawai ◽  
Hiroki Yokota ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Sulfuric Acid ◽  
Hybrid Material ◽  
Corrosion Property ◽  
Decomposition Process ◽  
Thermal Decomposition Process

Mechanism of CO2 Capture Technology Based on the Phosphogypsum Reduction Thermal Decomposition Process

2017 ◽  
Vol 31 (9) ◽  
pp. 9824-9832 ◽  
Author(s):  
Siqi Zhao ◽  
Liping Ma ◽  
Jie Yang ◽  
Dalong Zheng ◽  
Hongpan Liu ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Co2 Capture ◽  
Decomposition Process ◽  
Thermal Decomposition Process

Preparation, thermal decomposition process and kinetics for terbiump-methoxybenzoate ternary complex with 1,10-phenanthroline

2005 ◽  
Vol 79 (1) ◽  
pp. 181-186 ◽  
Author(s):  
J.-J. Zhang ◽  
R.-F. Wang ◽  
S.-P. Wang ◽  
H.-M. Liu ◽  
J.-B. Li ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Ternary Complex ◽  
Decomposition Process ◽  
Thermal Decomposition Process
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