6185-26-8Relevant academic research and scientific papers
An experimental and modelling study of ignition delays in shock-heated ethane-oxygen-argon mixtures inhibited by 2H-heptafluoropropane
Ikeda, Emi,Mackie, John C.
, p. 997 - 1009 (2007/10/03)
Ignition delay times have been measured behind reflected shock waves in ethane-oxygenargon mixtures at temperatures between 1150 and 1500 K and pre-ignition pressures between 10 and 14 atm. Delay times have been measured both by pressure rise and OH absorption at 307 nm. Kinetic modelling of the ignition delays has been made using the GRIMech 3.0 mechanism which with addition of several reactions involving HO2 radicals and an increase in the barrier for reaction between C2H5 and O2 can satisfactorily model delays over the studied equivalence ratios of φ= 1.7 to 0.68. Addition of 2H-heptafluoropropane up to 13 mol % (of ethane) had little inhibition effect on stoichiometric ethane-oxygen-argon mixtures but inhibited ignition in a mixture of φ= 1.5. A kinetic mechanism is presented to model the inhibition process. by Oldenbourg Wissenschaftsverlag, Muenchen.
The CF3C(O)O2 Radical. Its UV Spectrum, Self-Raction Kinetics, and Reaction with NO
Maricq, M. Matti,Szente, Joseph J.,Khitrov, Gregory A.,Francisco, Joseph S.
, p. 4514 - 4520 (2007/10/03)
Flash photolysis combined with time-resolved UV spectroscopy and transient infrared absorption is used to investigate the reactions of CF3C(O)O2 with itself, CF3O2, and nitric oxide.The UV spectrum of CF3C(O)O2 exhibits two bands, the stronger short wavelength component of which has a maximum cross section of 7.1E-18 cm2 at 207 nm.These bands are used to monitor the disappearance of CF3C(O)O2 and the secondary formation of CF3O2, yielding a self-reaction rate constant of (3.7 +5/-2)E-12 e(270 +/- 200)/T cm3 s-1.The cross reaction between CF3C(O)O2 and CF3O2 is found to be slow, having a rate constant of 3 s-1.Transient IR monitoring of the loss of NO and concomitant formation of NO2 leads to a rate constant of (4.0 +2.2/-1.4)E-12 e(563 +/- 115)/T cm3 s-1 for the reaction between CF3C(O)O2 and NO.This result implies that CF3C(O)O2 radicals formed as intermediates in the atmospheric degradation of hydrofluorocarbons (HFCs) are rapidly converted into CF3O2 radicals, which are in turn converted into carbonyl fluoride and FNO.
Kinetics of Reactions of Hydroxyl Radicals with a Series of Aliphatic Aldehydes
Dobe, S.,Khachatryan, L. A.,Berces, T.
, p. 847 - 852 (2007/10/02)
The kinetics of reactions of hydroxyl radical with acetaldehyde and its alkyl and halogen substituted derivatives has been investigated in the temperature range 298-520 K with the discharge flow/resonance fluorescence technique.The following reactions were studied and Arrhanius parameters were obtained (the preexponential factors are given in 1E12 cm3 mol-1 s-1, the activation energies in kJ mol-1 units): (1) OH + CF3CHO a = 7 (assumed) E = 5.9 (2) OH + CCl3CHO a = 7.1 +/- 1.5 E = 5.0 +/- 0.8 (3) OH + CH3CHO a = 5.2 +/- 1.1 E = -1.7 +/- 0.7 (4) OH + (CH3)2CHCHO a = 9.5 +/- 3.0 E = -2.6 +/- 1.2 (5) OH + (CH3)3CCHO A = 8 +/- 4 E = -3.4 +/- 1.7. - Key words: Chemical Kinetics / Elementary Reactions / Radicals
