Oxidized Species/Oxidizing Agent/Oxidant

Oxidized Species/Oxidizing Agent/Oxidant (O) the chemical species that undergoes the... 

Thermodynamic calculations for reactions forming carbon disulfide from the elements are compHcated by the existence of several known molecular species of sulfur vapor (23,24). Thermochemical data have been reported (12). Although carbon disulfide is thermodynamically unstable at room temperature, the equiHbtium constant of formation increases with temperature and reaches a maximum corresponding to 91% conversion to carbon disulfide at about 700°C. Carbon disulfide decomposes extremely slowly at room temperature in the absence of oxidizing agents. 

Low Oxidation State Chromium Compounds. Cr(0) compounds are TT-bonded complexes that require electron-rich donor species such as CO and C H to stabilize the low oxidation state. A direct synthesis of Cr(CO)g, from the metal and CO, is not possible. Normally, the preparation requires an anhydrous Cr(III) salt, a reducing agent, an arene compound, carbon monoxide that may or may not be under high pressure, and an inert atmosphere (see Carbonyls). 

The image-related transfer of a diffusible dye formed as a product of the oxidation of a dye containing a developing agent moiety was described in 1966 (32). This process depends on the preferential transfer of an oxidation product having greater mobility than the unoxidized species. Compound [13251 -03-1] (2), for example, a bis-sulfonjlhydrazide, upon oxidation releases [573-89-7] (3), a smaller, more mobile dye. 

There are situations where thermal oxidation may be preferred over catalytic oxidation for exhaust streams that contain significant amounts of catalyst poisons and/or fouling agents, thermal oxidation may be the only technically feasible control where extremely high VOC destmction efficiencies of difficult to control VOC species are required, thermal oxidation may attain higher performance and for relatively rich VOC waste gas streams, ie, having >20 25% lower explosive limit (LEL), the gas stream s explosive properties and the potential for catalyst overheating may require the addition of dilution air to the waste gas stream (12). 

Cosolvents ana Surfactants Many nonvolatile polar substances cannot be dissolved at moderate temperatures in nonpolar fluids such as CO9. Cosolvents (also called entrainers, modifiers, moderators) such as alcohols and acetone have been added to fluids to raise the solvent strength. The addition of only 2 mol % of the complexing agent tri-/i-butyl phosphate (TBP) to CO9 increases the solubility ofnydro-quinone by a factor of 250 due to Lewis acid-base interactions. Veiy recently, surfac tants have been used to form reverse micelles, microemulsions, and polymeric latexes in SCFs including CO9. These organized molecular assemblies can dissolve hydrophilic solutes and ionic species such as amino acids and even proteins. Examples of surfactant tails which interact favorably with CO9 include fluoroethers, fluoroacrylates, fluoroalkanes, propylene oxides, and siloxanes. 

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