title: Direct and indirect radiolytic effects in highly concentrated aqueous solutions of bromide.
abstract: Highly concentrated aqueous solutions of bromide were used to examine the total radical yield in the direct decomposition of water by γ-rays. Bromide concentrations were varied up to 6 M at which almost all OH(•) radicals, H(•) atoms, and hydrated electrons produced in the picosecond range oxidize bromide to ultimately form Br(3)(-), a stable species that can easily be measured with a spectrometer. Considering only the decomposition of water in the presence of air and in acidic conditions, the apparent yield of oxidizing species is found to be around (10 ± 0.05) × 10(-7) mol J(-1). The absorption of irradiation dose by the solute at high concentration is discussed and quantitatively evaluated. At 6 M Br(-) solutions, 38% of the dose is absorbed by solutes and Br(-) is directly ionized. The optimal value for the initial yield of the radicals produced by direct radiolytic Br(-) ionization is found to be (9.6 ± 0.5) × 10(-7) mol J(-1).
authors: Laboratoire de Chimie Physique, UMR 8000 CNRS/ Université Paris-Sud 11, Faculté des Sciences d'Orsay, Orsay, France.
authors: Anna
authors: A
authors: Balcerzyk
authors: Jay
authors: J
authors: LaVerne
authors: Mehran
authors: M
authors: Mostafavi
mesh_terms: D001965:Bromides / Q000737:chemistry*; D005720:Gamma Rays; D017665:Hydroxyl Radical / Q000737:chemistry; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D001965:Bromides; D012996:Solutions; D014867:Water; D017665:Hydroxyl Radical