Thermal desorption kinetics

Langmuir ◽  
1992 ◽  
Vol 8 (3) ◽  
pp. 774-781 ◽  
Author(s):  
H. J. Kreuzer
Keyword(s):  
Thermal Desorption ◽  
Desorption Kinetics

The Role of Cr in H Desorption Kinetics in Rapidly Solidified Al

2014 ◽  
Vol 783-786 ◽  
pp. 264-269 ◽  
Author(s):  
Iya I. Tashlykova-Bushkevich ◽  
Keitaro Horikawa ◽  
Goroh Itoh
Keyword(s):  
High Temperature ◽  
Thermal Desorption ◽  
High Purity ◽  
Thermal Desorption Spectroscopy ◽  
Secondary Phase ◽  
Hydrogen Desorption ◽  
Oxide Surface ◽  
Desorption Kinetics ◽  
Hydrogen Trapping ◽  
Rapidly Solidified

Hydrogen desorption kinetics for rapidly solidified high purity Al and Al-Cr alloy foils containing 1.0, 1.5 and 3.0 at % Cr were investigated by means of thermal desorption analysis (TDA) at a heating rate of 3.3°C/min. For the first time, it was found that oxide inclusions of Al2O3 are dominant high-temperature hydrogen traps compared with pores and secondary phase precipitates resulted in rapid solidification of Al and its alloys. The correspondent high-temperature evolution rate peak was identified to be positioned at 600°C for high purity Al and shifted to 630°C for Al-Cr alloys. Amount of hydrogen trapped by dislocations increases in the alloys depending on Cr content. Microstructural hydrogen trapping behaviour in low-and intermediate temperature regions observed here was in coincidence with previous data obtained for RS materials using thermal desorption spectroscopy (TDS). The present results on hydrogen thermal desorption evolution indicate that the effect of oxide surface layers becomes remarkable in TDA measurements and show advantages in combinations of both desorption analysis methods to investigate hydrogen desorption kinetics in materials.

Oxidation behaviour of zirconium hydride and its influence on the thermal desorption kinetics

2018 ◽  
Vol 134 ◽  
pp. 199-210 ◽  
Author(s):  
Mingwang Ma ◽  
Lei Wang ◽  
Yuan Wang ◽  
Wei Xiang ◽  
Binghua Tang ◽  
...  
Keyword(s):  
Thermal Desorption ◽  
Oxidation Behaviour ◽  
Zirconium Hydride ◽  
Desorption Kinetics

scholarly journals Chloroform desorption from poly(lactic acid) nanocomposites: a thermal desorption spectroscopy study

2020 ◽  
Vol 92 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Riccardo Checchetto ◽  
Daniele Rigotti ◽  
Alessandro Pegoretti ◽  
Antonio Miotello
Keyword(s):  
Lactic Acid ◽  
Thermal Desorption ◽  
Thermal Desorption Spectroscopy ◽  
Zero Order ◽  
Poly Lactic Acid ◽  
Desorption Kinetics ◽  
Residual Solvent ◽  
Medical Materials ◽  
Solvent Molecules ◽  
Second Peak

AbstractBiopolymer nanocomposites were prepared by solvent casting dispersing lauryl-functionalized cellulose nano-fibrils (CNF) in a poly(lactic acid) matrix (PLA). The release of residual chloroform (CHCl3) solvent molecules was studied by Thermal Desorption Spectroscopy (TDS) analysis. TDS spectra of the PLA matrix show a single desorption peak at TP = 393 K with FWHM ~10 K, compatible with a zero-order desorption kinetics. This narrow TDS peak was accurately reproduced assuming that: (i) the rate limiting step is given by the CHCl3 de-trapping from sites in the PLA matrix where residual solvent molecules form small aggregates and (ii) the activation energy for desorption linearly decreases from 1.19 eV for saturated traps to 1.11 eV when the traps occupancy by solvent molecules approaches zero. The balance energy term ϵD = −0.08 eV is due to the attractive interactions between trapped CHCl3 molecules. Adding CNF particles to the PLA matrix the zero-order peak shifts to lower temperatures and a second peak with FWHM ~60 K appears at higher temperatures. This second peak is compatible with a first-order desorption kinetics and is attributed to the release of dispersed CHCl3 molecules from trapping sites in PLA-CNF interface region. The obtained information are of interest for applications in food and electronic packaging and for the development of medical materials.

Desorption kinetics of hydrogen and deuterium from Si(111) 7×7 studied using laser‐induced thermal desorption

1988 ◽  
Vol 89 (3) ◽  
pp. 1709-1718 ◽  
Author(s):  
B. G. Koehler ◽  
C. H. Mak ◽  
D. A. Arthur ◽  
P. A. Coon ◽  
S. M. George
Keyword(s):  
Thermal Desorption ◽  
Desorption Kinetics ◽  
Kinetics Of

Associative desorption from adlayers of interacting particles: nitric oxide on Pt, Ni and Ru

1980 ◽  
Vol 370 (1743) ◽  
pp. 545-560 ◽  
Keyword(s):  
Thermal Desorption ◽  
Product Distribution ◽  
Desorption Kinetics ◽  
Lateral Interactions ◽  
Model Calculations ◽  
Mechanical Methods ◽  
Analytic Expressions ◽  
Statistical Mechanical ◽  
Kinetics Of ◽  
Quantitative Account

The kinetics of associative desorption from mixed adlayers containing two kinds of particles (N and 0) have been examined. Standard statistical mechanical methods have been employed to study the effects of lateral interactions (ω NN , ω NO , ω OO ) between near-neighbour particles on the desorption kinetics while the adlayer stoichiometry varies continuously during a desorption sweep. Although the most general case ω NN ≠ ω NO ≠ ω OO ≠ 0) is found to be mathematically intractable, either one of two useful approximations can lead to analytic expressions for the desorption rate of N 2 , NO and O 2 . Both of these approximations have been used to simulate the thermal desorption spectra from a 1:1 layer of N and O atoms absorbed on Pt, Ni and Ru surfaces. The results show that, although the operation of lateral interactions can profoundly affect the desorption kinetics of these systems they cannot significantly alter the product distribution. N 2 and O 2 are overwhelmingly the major products, with NO desorption being entirely negligible in every case. We therefore conclude that observations of molecular NO in thermal desorption in these systems is evidence of molecularly adsorbed NO on the surface. Such desorption of NO is not due to recombination of surface N and O atoms. Reasonable values of the interaction parameters are used in model calculations which give a fairly good quantitative account of the available experimental data. The comparison with experiment leads to the conclusion that O-O repulsions are significant in every case. The N-N interaction is either zero or slightly attractive on Pt and Ni, but is very definitely repulsive on Ru.

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