Activation energy determinations from dielectric thermal analysis of reacting polymeric systems

1991 ◽  
Vol 37 (10) ◽  
pp. 2407-2421 ◽  
Author(s):  
K. A. Nass ◽  
J. C. Seferis
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Polymeric Systems ◽  
Dielectric Thermal Analysis

The dielectric thermal analysis

1981 ◽  
Vol 104 (6) ◽  
pp. 763-767 ◽  
Author(s):  
Frigyes Egerer
Keyword(s):  
Thermal Analysis ◽  
Dielectric Thermal Analysis

Human cytokines characterized by dielectric thermal analysis, thermogravimetry, and differential scanning calorimetry

2012 ◽  
Vol 111 (3) ◽  
pp. 1707-1716 ◽  
Author(s):  
Salaam Saleh ◽  
Druthiman Reddy Mantheni ◽  
Manik Pavan Kumar Maheswaram ◽  
Susan Moreno-Molek ◽  
Tobili Sam-Yellowe ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry ◽  
Dielectric Thermal Analysis ◽  
Human Cytokines

Phase Formation Kinetics in Sol-Gel Derived Strontium Bismith Tantalate

2001 ◽  
Vol 666 ◽  
Author(s):  
Yun-Mo Sung ◽  
Woo-Chul Kwack
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Phase Formation ◽  
Sol Gel ◽  
Avrami Exponent ◽  
Fluorite Phase ◽  
X Ray Diffraction ◽  
Aurivillius Phases ◽  
Formation Kinetics ◽  
Isothermal Kinetic

ABSTRACTPhase formation characteristics of Sr0.7Bi2.4Ta2O9 (SBT) powder, synthesized via sol-gel and pyrolysis process, was investigated by using thermal analysis. Each of the two exotherms, appearing in differential thermal analysis (DTA) scan curves, was identified as crystallization of fluorite phase and transformation of fluorite to aurivillius phase, respectively by using x-ray diffraction (XRD). By applying non-isothermal kinetic analyses to the DTA results, activation energy values for the formation of fluorite and aurivillius phases were determined as 192 and 375 kJ/mol, respectively and Avrami exponent values for each reaction were determined as 0.91 and 0.96, respectively. These activation energy and Avrami exponent values were discussed in detail to understand phase formation mechanism in SBT system.

Thermal Stability vs. Crystallization of the Lithiumsilicate Glasses with Addition Zirconium Dioxide and Titanium Dioxide

2008 ◽  
Vol 39-40 ◽  
pp. 399-401
Author(s):  
Viliam Pavlík ◽  
Eugen Jóna ◽  
Martina Sapietová ◽  
Soňa Šnircová
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Analysis ◽  
Titanium Dioxide ◽  
Differential Thermal Analysis ◽  
Structural Analysis ◽  
Zirconium Dioxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Relationship

The glasses with composition of Li2O . 2 SiO2 . n ZrO2 . n TiO2 (where n = 0; 0.015; 0.031; 0.050; 0.075; 0.1; 0.15; 0.2) were prepared and the relationship between structural and selected parameters of thermal stability vs. crystallization has been studied by differential thermal analysis. Structural analysis was provided by X–ray diffraction. The order of thermal stability vs. crystallization representing of activation energy of studied glass systems which increase with higher addition both oxides. The same order was obtained from the values of XRD. On the comparison the glasses with zero addition titanium dioxide their activation energy was much higher.

Stability of the Pd-Co-Ni-Cu-P Metallic Glasses

2007 ◽  
Vol 1048 ◽  
Author(s):  
Daisuke Fukamaki ◽  
Tsunehiro Takeuchi ◽  
Masashi Hasegawa ◽  
Kazuo Soda ◽  
Hirokazu Sato ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Free Energy ◽  
Electronic Structure ◽  
Metallic Glass ◽  
Internal Energy ◽  
Metallic Glasses ◽  
Photoemission Spectroscopy ◽  
First Principle ◽  
Cluster Calculations

AbstractStability of Pd-Co-Ni-Cu-P metallic glass was investigated in terms of free energy using first principle cluster calculations, thermal analysis, and photoemission spectroscopy measurements. We found that the internal energy of the Pd-based metallic glasses is dominated by the electronic structure near the Fermi level. The analyses on the electronic structure and local atomic arrangements indicate that the substitution of cobalt or a hypothetical atom Co0.5Cu0.5 for nickel in the Pd40Ni40P20 metallic glass decreases the free energy of the Pd-Ni-P metallic glass by increasing entropy without altering significantly internal energy. On the basis of the idea mentioned above, we prepared Pd28Co24Ni24P24, Pd25Co25Ni25P25 and Pd40Co40/3Ni40/3Cu40/3P20 metallic glasses. These metallic glasses certainly showed the nearly highest TX, which directly reflect the activation energy against crystallization, among the Pd-based metallic glasses ever reported.

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