Radiation effects chemical changes

The physico-chemical changes induced in polymers following exposure to radiation can be studied by a range of spectroscopic techniques. Recent developments in instrumentation and data analysis procedures in electronic, vibrational and magnetic resonance spectroscopies have provided considerable new insights into polymer structure and behaviour. The application of these spectroscopic methods in polymer studies are reviewed with emphasis on their utility in investigations of radiation effects on macromolecules. 

In respect of radiation effects in polymers, the primary application of NMR spectroscopy is in chemical analysis to determine the changes in chemical structure which may occur on exposure. 

This law states that only those radiations which are absorbed can be effective in producing the chemical change. 

The dioxo ions M02 and MO + are stable with respect to the strength of the M-0 bond. These oxo ions do not resemble other oxo ions in that they can survive a variety of chemical changes. However, they do behave as if they are species intermediate between M+ and M2+. In the case of UO + and PuO + considerable stability is exhibited in aqueous solution the half-line for exchange with H2 80 is very long, however, the exchange can be catalyzed by the presence of reduced states or by selfreduction due to radiation effects. 

The primary target of biological effects appears to be the DNA (see Chap. 15), although effect on the cytoplasmic membrane may also play a role [8]. Ionizing radiation affects DNA in a number of ways. It causes chemical changes in specific nucleotide bases it causes single-strand breaks and it causes double-strand breaks in a dose-dependent manner. 

Radiation effects on polymers are more subtle than normal radiation chemistry, in that small chemical changes may have pronounced effects on the physical properties. Because of the sensitivity of these physical properties, the radiation chemistry of Polyox is best discussed in two parts—the chemical reactions occurring and the effects of these reactions on the physical properties. 

It appears that the chemical change produced by a given amount of energy degradation is far less sensitive to the rate of energy loss of the radiation in hydrocarbons than in water. While pure water behaves very differently when irradiated with radiations of differing ionization densities, the chemical effects in hydrocarbons appear to be quite insensitive... 

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