Evaluation of the enthalpy of formation of carbon nanotubes and their phase diagram

2015 ◽  
Vol 10 (9-10) ◽  
pp. 689-695 ◽  
Author(s):  
S. A. Gubin ◽  
I. V. Maklashova ◽  
E. I. Zakatilova
Keyword(s):  
Carbon Nanotubes ◽  
Phase Diagram ◽  
Enthalpy Of Formation ◽  
The Enthalpy Of Formation

Enthalpy of Formation of Cu2PbO2 and Revision of the Cu2O-PbO Phase Diagram

2005 ◽  
Vol 494 ◽  
pp. 67-72 ◽  
Author(s):  
M. Čančarević ◽  
Matvei Zinkevich ◽  
Fritz Aldinger
Keyword(s):  
Phase Diagram ◽  
Enthalpy Of Formation ◽  
Eutectic Reaction ◽  
Enthalpy Of Reaction ◽  
Quartz Ampoule ◽  
Gibbs Energy Of Formation ◽  
Synthesis Conditions ◽  
Optimum Synthesis ◽  
The Enthalpy Of Formation ◽  
Energy Of Formation

The stoichiometric compound Cu2PbO2 has been synthesized by solid-state reaction from Cu2O and PbO in a sealed quartz ampoule. The optimum synthesis conditions are 910 K and 260 h. The enthalpy of formation of Cu2PbO2 has been measured with the use of high-temperature calorimeter. The enthalpy of reaction Cu2O + PbO = Cu2PbO2 is – 25.4 ± 1 kJ·mol-1 at temperature 968 ± 5 K. Standard enthalpy and Gibbs energy of formation of the Cu2PbO2 compound from elements and its entropy at 298.15 K are DfH° = – 413.086 kJ·mol-1, DfG° = – 353.165 kJ·mol-1 and S° = 135.165 J·mol-1·K-1. The eutectic reaction L → Cu2O + PbO was found to occur at 1017 ± 5 K. Using the thermodynamic database for Cu-Pb-O system the revised Cu2O-PbO phase diagram is proposed.

Collapse phase diagram of carbon nanotubes with arbitrary number of walls. Collapse modes and macroscopic analog

Carbon ◽  
2021 ◽  
Author(s):  
Y. Magnin ◽  
F. Rondepierre ◽  
W. Cui ◽  
D.J. Dunstan ◽  
A. San-Miguel
Keyword(s):  
Carbon Nanotubes ◽  
Phase Diagram ◽  
Arbitrary Number ◽  
Collapse Phase

Thermochemistry of Organic and Heteroorganic Species. Part IX. Photoionization Studies of Isomerization and Fragmentation of Polysubstituted Cyclopropenes: Phenyl-Substituted Cyclopropenes

2000 ◽  
Vol 6 (1) ◽  
pp. 53-64 ◽  
Author(s):  
V.V. Takhistov ◽  
I.N. Domnin ◽  
D.A. Ponomarev
Keyword(s):  
Mass Spectrometry ◽  
Enthalpy Of Formation ◽  
Good Alternative ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Ion Structure ◽  
Photoionization Mass Spectrometry ◽  
General Methodology ◽  
Fragment Ions ◽  
The Enthalpy Of Formation

Ionization and appearance energies of some fragment ions from 1,2,3-trimethy1-3-phenyl-, 3-methyl-1,2,3-triphenyl-, 1,2-diphenyl-3-methoxycarbonyl-, 1,2,3-triphenyl-3-methoxycarbonyl- and 1,3,3-triphenyl-2-methoxycarbonyl-cyclopropenes were measured by photoionization mass spectrometry. It was shown that in none of these compounds did the fragment ions possess the expected stable substituted cyclopropenium ion structure. Accordingly, possible schemes of molecular ion isomerization are given. The enthalpies of formation of nearly 50 substituted cyclopropenium ions, and ions of related structure, were estimated using series of isodesmic reactions. This publication, together with the previous works of the authors in this Journal, demonstrates the general methodology for estimation of the enthalpy of formation for even-electron ions. It is suggested that the present methodology can provide a good alternative to other estimation or computation procedures applied to the thermochemistry of ions.

Measurement of the enthalpy of formation of an iron pico-hydride and of its main properties

2017 ◽  
Vol 31 (25) ◽  
pp. 1745007
Author(s):  
Jacques Dufour ◽  
Xavier Dufour ◽  
Fabienne Dioury ◽  
Jenny D. Vinko
Keyword(s):  
Enthalpy Of Formation ◽  
Electric Dipole ◽  
Atomic System ◽  
Binding Energies ◽  
Iron Nucleus ◽  
Atomic Size ◽  
The Standard Model ◽  
Typical Distances ◽  
Species Being ◽  
The Enthalpy Of Formation

Chemical reactions result from the outside shell electrons of the reacting species being shared in various types of combinations. Typical distances involved are tenths of nm, resulting in binding energies typically in the order of hundreds of kJ/mole (eV/atom). The synthesis of a novel “atomic system” formed from Iron and di-Hydrogen has been achieved. The measured enthalpy of formation is some 40 MJ/moleFe and the distance between the hydrogen proton and the iron nucleus is some 8 pm, hence the proposed name: Iron Pico-Hydride. This compound is a permanent electric dipole of atomic size. Pico-Hydrides could, thus, play a significant role in HT superconductivity and in super-capacitors. The synthesis is compatible with the standard model.

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