Chlorinated radiation chemistry

Early studies of the radiation chemistry of chlorinated hydrocarbons demonstrated the formation of molecular cations of aromatic hydrocarbons with half-lives of the order of a few micoseconds [26]. In solutions containing two different aromatic solutes, it was possible to measure the rate of electron transfer from the neutral molecule to the radical cation. Some specific examples of other studies are given below. 

The flux of DOC from terrestrial landscapes to surface runoff has wide-ranging consequences for aquatic chemistry and biology. DOC affects the complexation, solubility, and mobility of metals (Perdue et al., 1976 Driscoll et al., 1988 Martell et al., 1988 see Chapter 8) as well as the adsorption of pesticides to soils (Senesi, 1992 Worrall et al., 1997). Formation of trihalomethanes when drinking water is disinfected with chlorine, a worldwide threat to water supplies, is also linked to DOC concentrations (Siddiqui et al., 1997). DOC attenuates ultraviolet-B (UV-B) radiation and thus provides some protection to aquatic biota from exposure to harmful UV radiation (e.g., Williamson and Zagarese, 1994). Finally, DOC affects the heat balance and thus stratification in lakes, which is an important constraint for aquatic organisms with limited habitats (Schindler et al., 1996, 1997). 

Block copolymer chemistry provides a convenient means of incorporating the oxygen-RIE-resistant polysiloxane moiety into a high-Tg, radiation-sensitive polymer (20). The flow characteristics of the resist are determined by the unit with higher Tg, and problems associated with phase separation are minimized because of block copolymerization. Specifically, block copolymers of dimethylsiloxane and chlorinated p-methylstyrene exhibit good sensitivity, resolution, and thermal properties and low rates of erosion during O2 RIE. 

Methane is the most abundant hydrocarbon in the atmosphere. It plays important roles in atmospheric chemistry and the radiative balance of the Earth. Stratospheric oxidation of CH4 provides a means of introducing water vapor above the tropopause. Methane reacts with atomic chlorine in the stratosphere, forming HCl, a reservoir species for chlorine. Some 90% of the CH4 entering the atmosphere is oxidized through reactions initiated by the OH radical. These reactions are discussed in more detail by Wofsy (1976) and Cicerone and Oremland (1988), and are important in controlling the oxidation state of the atmosphere. Methane absorbs infrared radiation in the troposphere, as do CO2 and H2O, and is an important greenhouse gas (Lacis et al., 1981 Ramanathan et al., 1985). 

Uzun, C., Ilgm, R, Giiven, O., Radiation induced in-situ generation of conductivity in the blends of polyaniUne-base with chlorinated-pol5dsoprene. Radiation Physics and Chemistry 2010, 79,343-346. 

The ozone layer in the stratosphere filters the high-energy ultraviolet radiation out of the sunlight and in this way enables life on earth. Since midst of the seventies a drastic decrease in the ozone concentration above the antarctic region has been observed in September and October every year, and since 1990 also above the arctic region. Investigating the role of chlorine in the atmospheric chemistry it was found, that chlorofluorocarbons can reach the stratosphere, where they decompose and release halogens that affect the ozone layer [357]. 

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