Fluorine surface active additives

Chemical resistance and thermostability of nano-heterogenic coatings with fluorine surface active additives (FSAA) are approximately 5%-10% higher than for unmodified ones. At the same time, addition of about 3 mass% of metal oxides in epoxy-rubber nanostructured compositions significantly decreases their permeability and increases their chemical resistance in water and water solutions of acids, salts, and alkalis (Figure 6.3) [8],... 

Formation of nano-heterogenic systems with fluorine-containing surface active additives of optimal chemical composition is an effective method of obtaining advanced coatings. 

The partially fluorinated compoxmds used in this investigation as surface active additives are listed in Table I. 

Catalysis. Catalytic properties of the activated carbon surface are useful in both inorganic and organic synthesis. For example, the fumigant sulfuryl fluoride is made by reaction of sulfur dioxide with hydrogen fluoride and fluorine over activated carbon (114). Activated carbon also catalyzes the addition of halogens across a carbon—carbon double bond in the production of a variety of organic haUdes (85) and is used in the production of phosgene... 

The presence at the catalyst s surface of active sites which made possible the dehydrofluorination reaction (C-F rupture) and the chlorine-fluorine substitution (C-Cl rupture) was then supposed There would also exist active sites which would only allow the second reaction (C-Cl nipture). The addition of nickel, by suppressing the sites which allow the two reactions (fluorination and dehydrofluorination) decreases the total activity. 

FIC Ratio Model. The fluorine-to-carbon ratio (F/C) of the active species can be used (92) to explain the observed etch results (Figure 8). This model does not consider the specific chemistry occurring in a glow discharge but, rather, views the plasma as a ratio of fluorine species to carbon species that can react with a silicon surface. The generation or elimination of the active species by various processes or gas additions then modifies the initial F/C ratio of the inlet gas. 

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