Edwin J. Hart

The Radiolysis of Aqueous Solutions at High Intensities

the presence of acid), hydrogen atoms, and hydroxyl radicals. These species are produced in localized regions along the track of the incident radiation. These regions of high radical concentrations expand, and while this process is occurring radical-radical reactions take place leading to hydrogen, hydrogen peroxide, and regenerated water, while radical-solute reactions will also occur to an extent depending on the reactivity and concentration of the solute and the state of expansion of the localized regions. Calculations by various workers (3-6) using the free radical theory have been quite successful in explaining many of the aspects of the radiation chemistry of aqueous systems. A point of uncertainty in the calculations has been the necessity to assume rate constants for the free radical reactions and to assume values for the parameters used to describe the heterogeneous distribution of the radicals produced, and their eventual diffusion and reaction. In the present work conditions were used such that intertrack reactions were important and the diffusion of the radicals from their tracks before chemical reaction took place was sufficient so that they may be considered as being produced homogeneously. An important factor in the irradiation procedure was that the radiation was produced in pulses of a duration such that no significant chemical reaction took place during the pulse. Thus at the end of such a pulse a known concentration of radicals was produced the subsequent reactions of which were described mathematically by normal homogeneous kinetics.

Chemical Reactions of Organic Compounds with X‐Ray Activated Water

Gas free solutions of carbon monoxide, alcohols, aldehydes, ketones and acids were irradiated in the concentration range 10 μM to 1 M, between pH=1 to 13 and the reactions studied principally by gas analysis and potentiometric acid analysis. One organic component systems and, to a more limited extent, two organic component systems were investigated. To obtain significant results, foreign organic matter must be strictly excluded from the low concentration solutions and the methods used to accomplish this are described. Organic impurities in the water can be detected by irradiating the water with x‐rays and measuring the evolved hydrogen and carbon dioxide. The reactions cannot be briefly abstracted, but oxidation and condensation reactions with the evolvement of gaseous hydrogen are important in the effect of the rays. Carbon dioxide was produced from certain acids, particularly strongly from those having an oxygen containing group in the α‐position. No liberation of carbon monoxide, hydrocarbons or oxygen...

Primary radical yields in pulse irradiated alkaline aqueous solution

Relative primary radical yields of hydrated electrons, H atoms, and OH radicals were determined by measuring the amount of hydrated electron formed following a single 4-μsec pulse of X-rays. In neutral solution the amount of hydrated electron produced corresponds to

PRIMARY RADICAL YIELDS AND SOME RATE CONSTANTS IN HEAVY WATER.

G({\rm e}_{{\rm aq}}^{-})

Chemical Yields of Ionizing Particles in Aqueous Solutions: Effect of Energy of Protons and Deuterons

, and at high pHs an additional amount is formed corresponding to G(H) by the reaction

Radiation Chemistry of Some Sulfonephthalein Dyes

{\rm H}+{\rm OH}^{-}={\rm H}_{2}{\rm O}+{\rm e}_{{\rm aq}}^{-}

Studies of Reactions Induced by the Photoactivation of the Water Molecule. I

. In the presence of dissolved hydrogen the OH radical in yield G(OH) is also converted to hydrated electrons by reaction with hydrogen. The high optical absorption of the hydrated electron at 7000 A is used as a measure of its concentration. A pH range from 7 to 14.5 is covered. At pH above 12 the total radical yield,

Chemical Yields of Ionizing Radiations in Aqueous Solutions: Effect of Energy of Alpha Particles'

G({\rm e}_{{\rm aq}}^{-})+G({\rm H})+G({\rm OH})

Absorption Spectrum of the Hydrated Electron in Water and in Aqueous Solutions

, is constant, as is the total reducing yield,

Rate Constants of Hydrated Electron Reactions with Organic Compounds1

G({\rm e}_{{\rm aq}}^{-})+G({\rm H})