Centre of Radiation Research and Technology

The main experimental method used in the Lab is pulse radiolysis with UV/VIS detection based on the electron linear accelerator LAE10. The LAE10 accelerator has been constructed at the Institute of Nuclear Chemistry and Technology (INCT) and was installed in 1999. The LAE 10 has been solely dedicated to pulse radiolysis experiments and related work in the field of radiation chemistry with the following nominal parameters: electron energy 10 MeV, pulse duration 4-10 ns and 100 ns, peak current 1A, beam power 0.2 kW and repetition rate 1, 12.5, 25 Hz and single pulse mode.

Research at Radical Chemistry Group focuses on oxidation effects in media, with particular emphasis on the identities and molecular structure of short-lived transients and reaction mechanisms.

Subject involves application of radiation methods for the study of OH-induced oxidation of sulfur-containing alcohols, carboxylic acids, amino acids and their derivatives, and peptides. It is concerned with the characterization and quantification of reactive intermediates, such as hydroxysulfuranyl radicals, radicals and radical cations with various 2-center/3-electron bonds, reaction kinetics and the measurement of absolute rate constants for elementary processes involving these reactive intermediates, such as intramolecular proton and electron transfer, beta-fragmentation, decarboxylation, and reaction with molecular oxygen. The sulfur intermediates can undergo a variety of subsequent reactions depending on conformational flexibility of molecules and functional neighboring groups present in molecules.

Ionic liquids (ILs) are fluids at room temperature consisting entirely of ions. The character and strength of interactions between cations and anions are responsible for determination of their properties. Therefore, various combinations of cations and anions can be used to obtain desired properties. Typically, ILs exhibit: low melting point (a consequence of a poorly packed crystallographic system), negligible vapor pressure (a consequence of a strong anion-cation interaction), non-combustibility (consequence of a low vapor pressure), high electrical conductivity (a consequence of an ionic structure), ability to solubilize a wide range of solutes (e.g. organic, inorganic, polymers, enzymes), potential to be reused (easily separable from product/reactant mixtures) etc. These properties give ILs certain advantages over conventional molecular solvents and a wide range of potential applications that have generated considerable interest in their study.
Among possible applications, ILs can be used as a safer medium for transformations in the nuclear fuel cycle (fuel production, reprocessing, nuclear waste reduction, transportation, etc.). In particular, salts containing boron or chlorine atoms (efficient thermal neutron poisons) are very promising materials. Before ILs can be used in such application, first, it is necessary to characterize their radiation chemistry, such as identification of the radiolytically generated species and their reactivity. Such investigation are main goal of our group.