Free radicals generated by radiolysis of aqueous solutions

The free radicals produced in the radiolysis of aqueous solutions span the range of redox potentials from -2.9 to +2.65 volts. The identity and nature of these radicals were discussed. Most of the discussion was results obtained with low LET radiation sources (60Co gamma radiation or electron accelerators). Water radiolysis provides the synthesis of many radicals and radical ions in aqueous solution. The primary radicals, e/sub aq/- H, OH, are well characterized. The radical population can be made to be 90% pure OH (or O-) if N2O solutions are irradiated, the remaining 10% being H atoms. 55% of the radicals can be converted to H atoms in acid solution or in neutral phosphate solutions(e/sub aq/- reacts with H2PO4- to produce H). The remaining 45% (OH radicals) are difficult to convert to H by reaction with H2, due to the slow rate of the reaction. About 100 atmospheres of H2 are required to do the conversion in less than 10-6 sec. 3 figures, 3 tables. (DP)