scholarly journals Comparison of gas-phase free-radical populations in tobacco smoke and model systems by HPLC.

2001 ◽  
Vol 109 (8) ◽  
pp. 765-771 ◽  
Author(s):  
T M Flicker ◽  
S A Green
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Tobacco Smoke ◽  
Model Systems

Gas-Phase Anionic Metal Clusters are Model Systems for Surface Oxidation: Kinetics of the Reactions of Mn– with O2 (M = V, Cr, Co, Ni; n = 1–15)

2021 ◽  
Vol 125 (10) ◽  
pp. 2069-2076
Author(s):  
Brendan C. Sweeny ◽  
David C. McDonald ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
Juergen Troe ◽  
...  
Keyword(s):  
Gas Phase ◽  
Oxidation Kinetics ◽  
Metal Clusters ◽  
Surface Oxidation ◽  
Model Systems ◽  
Kinetics Of

scholarly journals Cecil Edwin Henry Bawn. 6 November 1908 — 19 September 2003

2021 ◽  
Author(s):  
Richard J. Puddephatt
Keyword(s):  
Physical Chemistry ◽  
Free Radical ◽  
Gas Phase ◽  
Faculty Members ◽  
Radical Reactions ◽  
Polymer Chemistry ◽  
Diverse Group ◽  
High Explosives ◽  
Free Radical Reactions ◽  
The University

Cecil Bawn was a physical chemist with particular expertise in chemical kinetics. Early in his career he made pioneering studies of free radical reactions in the gas phase and, during the war years, on the chemistry of high explosives. From mid career, he was one of the pioneers of polymer chemistry and established and led a strong and diverse group of polymer scientists at the University of Liverpool. He was a private and enigmatic person, with a strong sense of duty. His caring and helpful attitude was greatly appreciated locally by his students and younger faculty members. Nationally, he made outstanding service contributions to physical chemistry and polymer chemistry.

scholarly journals Effect of inorganic nanoparticles and organic complexes on their basis on free-radical processes in some model systems

2015 ◽  
Vol 31 (2) ◽  
pp. 138-145 ◽  
Author(s):  
K. A. Averchenko ◽  
N. S. Kavok ◽  
V. K. Klochkov ◽  
O. O. Sedyh ◽  
S. L. Yefimova ◽  
...  
Keyword(s):  
Free Radical ◽  
Inorganic Nanoparticles ◽  
Model Systems ◽  
Free Radical Processes ◽  
Organic Complexes ◽  
Radical Processes

scholarly journals Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

2013 ◽  
Vol 9 ◽  
pp. 1907-1916 ◽  
Author(s):  
Catrin Goeschen ◽  
Uta Wille
Keyword(s):  
Free Radical ◽  
Environmental Conditions ◽  
Hot Spots ◽  
Polymer Materials ◽  
Model Systems ◽  
Night Time ◽  
High Performing ◽  
Work Model ◽  
Product Study ◽  
Insight Into

Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions.

An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues

2016 ◽  
Vol 18 (15) ◽  
pp. 10207-10217 ◽  
Author(s):  
Ivan Ljubić ◽  
Antti Kivimäki ◽  
Marcello Coreno
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Excitation Spectra ◽  
Core Excitation ◽  
The Core ◽  
Nitroxide Free Radical ◽  
Phase Spectra ◽  
Stable Nitroxide

Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.

Hydroxyl radical initiated oxidation of formic acid on mineral aerosols surface: a mechanistic, kinetic and spectroscopic study

2015 ◽  
Vol 12 (2) ◽  
pp. 236 ◽  
Author(s):  
Cristina Iuga ◽  
C. Ignacio Sainz-Díaz ◽  
Annik Vivier-Bunge
Keyword(s):  
Free Radical ◽  
Formic Acid ◽  
Gas Phase ◽  
Atmospheric Aerosols ◽  
Carbonic Acid ◽  
Radical Reactions ◽  
Acid Molecule ◽  
Formyl Radical ◽  
Volatile Organic ◽  
Silicate Surface

Environmental context The presence of air-borne mineral dust containing silicates in atmospheric aerosols should be considered in any exploration of volatile organic compound chemistry. This work reports the mechanisms, relative energies and kinetics of free-radical reactions with formic acid adsorbed on silicate surface models. We find that silicate surfaces are more likely to act as a trap for organic radicals than to have a catalytic effect on their reactions. Abstract Heterogeneous reactions of atmospheric volatile organic compounds on aerosol particles may play an important role in atmospheric chemistry. Silicate particles are present in air-borne mineral dust in atmospheric aerosols, and radical reactions can be different in the presence of these mineral particles. In this work, we use quantum-mechanical calculations and computational kinetics to explore the reaction of a hydroxyl free radical with a formic acid molecule previously adsorbed on several models of silicate surfaces. We find that the reaction is slower and takes place according to a mechanism that is different than the one in the gas phase. It is especially interesting to note that the reaction final products, which are the formyl radical attached to the cluster surface, and a water molecule, are much more stable than those formed in the gas phase, the overall reaction being highly exothermic in the presence of the surface model. This suggests that the silicate surface is a good trap for the formed formyl radical. In addition, we have noted that, if a second hydroxyl radical approaches the adsorbed formyl radical, the formation of carbonic acid on the silicate surface is a highly exothermic and exergonic process. The carbonic acid molecule remains strongly attached to the surface, thus blocking CO2 formation in the formic acid oxidation reaction. The spectroscopic properties of the systems involved in the reaction have been calculated, and interesting frequency shifts have been identified in the main vibration modes.

High Performance Liquid Chromatographic Determination of Selected Gas Phase Carbonyls in Tobacco Smoke

1983 ◽  
Vol 66 (1) ◽  
pp. 8-12
Author(s):  
Delmar L Manning ◽  
Michael P Maskarinec ◽  
Roger A Jenkins ◽  
Amos H Marshall
Keyword(s):  
Gas Phase ◽  
Tobacco Smoke ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Published Data ◽  
Liquid Chromatographic Determination ◽  
Derivatizing Reagent ◽  
Liquid Chromatographic

Abstract Low molecular weight gas phase carbonyls in tobacco smoke are separated as 2,4-dinitrophenylhydrazones and determined by reverse phase high performance liquid chromatography. A trapping procedure is used whereby the gas phase carbonyls are reacted with the derivatizing reagent in a closed system. The deliveries of acetaldehyde and acrolein are compared with published data. In addition, propionaldehyde and acetone deliveries of selected cigarettes are reported.

Sign in / Sign up

Export Citation Format

Share Document