Room temperature oxidation rate constants of ultra- thin (discontinuous) molybdenum films

1976 ◽  
Vol 39 ◽  
pp. 125-131 ◽  
Author(s):  
S.M. Deshpande
Keyword(s):  
Rate Constants ◽  
Oxidation Rate ◽  
Room Temperature ◽  
Temperature Oxidation

Oxidation of (1-hydroxybenzyl)ferrocene and its derivatives substituted in phenyl ring with bis(triphenylsilyl) chromate

1982 ◽  
Vol 47 (12) ◽  
pp. 3375-3380 ◽  
Author(s):  
Jaroslav Holeček ◽  
Karel Handlíř ◽  
Milan Nádvorník ◽  
Milan Vlček
Keyword(s):  
Linear Dependence ◽  
Rate Constants ◽  
Oxidation Rate ◽  
Phenyl Ring ◽  
Equilibrium Constants ◽  
Aprotic Solvents ◽  
Protonation Equilibrium ◽  
Oxidation Of Alcohols ◽  
Hammett Σ Constants ◽  
Sulphuric Acid Medium

Kinetics have been studied of oxidation of (1-hydroxybenzyl)ferrocenes substituted in phenyl ring with bis(triphenylsilyl) chromate in benzene solutions as well as protonation of these alcohols in sulphuric acid medium. Logarithms of the oxidation rate constants (kobs, 20-40 °C) and those of the protonation equilibrium constants (KR+, 25 °C) show linear dependence on the Hammett σ constants, the ρ constant values being -0.86 to -0.40 and -2.50, respectively. These negative values suggest that the both processes are influenced by the same effects and confirm the mechanism proposed earlier for oxidation of alcohols with ferrocenyl substituent by action of bis(triphenylsilyl) chromate in aprotic solvents.

scholarly journals Graphene oxide prepared by a room temperature oxidation using a green mechanochemical method.

2021 ◽  
Vol 27 (S1) ◽  
pp. 726-728
Author(s):  
G. Tarango-Rivero ◽  
G. Herrera-Perez ◽  
C. Carreño-Gallardo ◽  
C.G. Garay-Reyes ◽  
I. Estrada-Guel ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Room Temperature ◽  
Mechanochemical Method ◽  
Temperature Oxidation

scholarly journals The influence of high-temperature oxidation on the phase distribution of metal substrate in duplex stainless steel

2021 ◽  
Author(s):  
Minami Matsumoto ◽  
Ken Kimura ◽  
Natsuko Sugiura
Keyword(s):  
Stainless Steels ◽  
Room Temperature ◽  
Phase Distribution ◽  
High Strength ◽  
Metal Substrate ◽  
Temperature Oxidation ◽  
Good Corrosion Resistance ◽  
Mn Oxide ◽  
Typical Type ◽  
Compositional Changes

AbstractDuplex stainless steels (DSSs), which consist of ferrite and austenite phases, are widely used owing to their high strength and good corrosion resistance. However, the oxidation behavior of DSSs is extremely complicated because they have dual phases. In this study, changes in the scale and the metal substrate during oxidation were investigated. UNS S32101 (Fe-21.5%Cr–5%Mn–1.5%Ni–0.3%Mo–0.22%N), which is a typical type of DSS, was annealed at 1473 K for up to 36 ks in air. The microstructure of UNS S32101 consisted of austenite/ferrite phases, the ratio of which was 50:50 at room temperature. After oxidation, Cr, Mn-oxide formed predominantly. The metal substrate beneath the scale changed mostly to ferrite. In the same region, depletion of Mn and N concentrations resulted. The decrease in Mn was due to the formation of Cr, Mn-oxide. In addition, it was revealed that N content of the metal substrate decreased due to the formation of N2 gas along with the depletion of Mn. It was assumed that the decrease in Mn and N, which are austenite-stabilized elements, led to an increase in ferrite in the depletion area of Mn and N. From this result, it was expected that the compositional changes in the Mn/N depletion area were caused by the oxidation of steel.

Room temperature oxidation of chromium and nickel implanted iron, and bulk alloys

1983 ◽  
Vol 15 (1-4) ◽  
pp. 66-74 ◽  
Author(s):  
P.J. Osborne ◽  
P.J.K. Paterson ◽  
O. Spillecke
Keyword(s):  
Room Temperature ◽  
Temperature Oxidation ◽  
Bulk Alloys

An experimental study of the reactivity of the hydroxide anion in the gas phase at room temperature, and its perturbation by hydration

1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Experimental Study ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Gas Phase Reactions ◽  
Flowing Afterglow ◽  
Hydroxide Anion

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.

The mechanism at the initial stage of the room-temperature oxidation of coal

2005 ◽  
Vol 140 (4) ◽  
pp. 332-345 ◽  
Author(s):  
Ting Shi ◽  
Xiaofang Wang ◽  
Jun Deng ◽  
Zhenyi Wen
Keyword(s):  
Room Temperature ◽  
Temperature Oxidation ◽  
Initial Stage

REACTION OF OXYGEN ATOMS WITH BUTADIENE

1960 ◽  
Vol 38 (11) ◽  
pp. 2187-2195 ◽  
Author(s):  
R. J. Cvetanović ◽  
L. C. Doyle
Keyword(s):  
Pressure Dependence ◽  
Rate Constants ◽  
Room Temperature ◽  
Relative Rate ◽  
Excess Energy ◽  
General Mechanism ◽  
Arrhenius Parameters ◽  
Heats Of Reaction ◽  
Relative Rate Constants ◽  
Oxygen Atoms

Reaction of oxygen atoms with 1,3-butadiene has been investigated at room temperature. It is found that it conforms to the general mechanism established previously for the analogous reactions of monoolefins. Only 1,2-addition occurs, and the addition products, butadiene monoxide and 3-butenal, possess excess energy when formed as a result of high heats of reaction. The pressure dependence of the formation of the addition products yields the values of the "lifetimes" of the initially produced "hot" molecules. The relative rate constants have been determined at 25 and 127 °C and from these the relative values of the Arrhenius parameters have been calculated.

COMBINATION AND DISPROPORTIONATION OF ETHYL RADICALS: INFLUENCE OF THE REACTION H+C2H5 = C2H6

1955 ◽  
Vol 33 (5) ◽  
pp. 821-829 ◽  
Author(s):  
Moyra J. Smith ◽  
Patricia M. Beatty ◽  
J. A. Pinder ◽  
D. J. Le Roy
Keyword(s):  
Light Intensity ◽  
Excellent Agreement ◽  
Mercury Concentration ◽  
Rate Constants ◽  
Room Temperature ◽  
Low Light ◽  
Ethylene Concentration ◽  
Light Intensities ◽  
Ethyl Radicals ◽  
Hydrogenation Of Ethylene

The mercury (3P1) photosensitized hydrogenation of ethylene has been studied at room temperature as a function of ethylene concentration, mercury concentration, and light intensity. In addition to combination and disproportionation, ethyl radicals have been shown to take part in the reaction[Formula: see text]The conditions favoring this reaction have been established and anomalous values previously found for the ratio of ethane to butane have been explained. The value obtained for the ratio of the rate constants for the disproportionation and combination of ethyl radicals, 0.15 ±.01, is in excellent agreement with the values obtained by other methods. Hexane formation is of some importance at low light intensities and high ethylene concentrations, and is adequately accounted for by the reactions[Formula: see text]

scholarly journals Structure–activity relationship for the estimation of OH-oxidation rate constants of carbonyl compounds in the aqueous phase

2013 ◽  
Vol 13 (23) ◽  
pp. 11625-11641 ◽  
Author(s):  
J.-F. Doussin ◽  
A. Monod
Keyword(s):  
Aqueous Phase ◽  
Rate Constants ◽  
Oxidation Rate ◽  
Carbonyl Compounds ◽  
Estimation Method ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Oh Radicals ◽  
Structure Activity ◽  
Polyfunctional Compounds

Abstract. In the atmosphere, one important class of reactions occurs in the aqueous phase in which organic compounds are known to undergo oxidation towards a number of radicals, among which OH radicals are the most reactive oxidants. In 2008, Monod and Doussin have proposed a new structure–activity relationship (SAR) to calculate OH-oxidation rate constants in the aqueous phase. This estimation method is based on the group-additivity principle and was until now limited to alkanes, alcohols, acids, bases and related polyfunctional compounds. In this work, the initial SAR is extended to carbonyl compounds, including aldehydes, ketones, dicarbonyls, hydroxy carbonyls, acidic carbonyls, their conjugated bases, and the hydrated form of all these compounds. To do so, only five descriptors have been added and none of the previously attributed descriptors were modified. This extension leads now to a SAR which is based on a database of 102 distinct compounds for which 252 experimental kinetic rate constants have been gathered and reviewed. The efficiency of this updated SAR is such that 58% of the rate constants could be calculated within ±20% of the experimental data and 76% within ±40% (respectively 41 and 72% for the carbonyl compounds alone).

Sign in / Sign up

Export Citation Format

Share Document