The Laboratory of Chain and Radical Reactions

Head of the Laboratory, Dr.Sci., professor I.A.Vardanyan
 

Scientific activity

  • oxidation and ignition of organic compounds,

  • reactions of radicals in gas phase and on solid surfaces,

  • atmospheric chemistry
     

Main achievements

1. Dynamic modes of the methane and acetaldehyde oxidation regarding heterogeneous radical stages have been modeled. Studying special points of the process has shown that heterogeneous stages strongly influence on the initiation of oscillatory oxidation mode. Depending on the rate constants of heterogeneous recombination of peroxy radicals and their interaction with inhibitor (formaldehyde) extinguishing or self-accelerating oscillations of concentrations were observed.
2. Heterogeneous interactions of peroxy radicals with methane and nitrogen dioxide on the various salts simulating substantial aerosols have been investigated. Efficient rate constants and activation energy of reactions of CH3O2 radical with CH4 and NO2 on the surfaces of KCI and NaCI were evaluated. The results obtained specify that heterogeneous interaction of RO2 radicals with methane and nitrogen dioxide can result in essential contribution to the processes proceeding in the atmosphere at the presence of aerosoles.
3. Researches on heterogeneous radical initiation of the low-temperature oxidation and ignition of organic compounds by the peroxy radicals formed at decomposition of organic peroxides and adsorbed on reaction vessel walls have revealed the influence of the nature and sizes of the reaction vessel surface, type and concentration of the peroxide on the ignition temperature (Tign.) of mixtures of aliphatic aldehydes with oxygen. Analyzing the dependence of Tign. on the quantity of adsorbed peroxide, two critical values of the initiator quantity were established leading to sharp fall in Tign. (up to room temperature). It was established that at small amounts of the initiator the first sharp decrease is caused by generation of radicals at heterogeneous decomposition of the initiator.
 

 

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