Stabilization using alkaline ions

Surface silanol groups of silica aquasols stabilized in an alkaline medium exchange protons for the alkaline ion such as Na+, K+, or NH4+ (Figure 13). The surface silanol groups can be esterified, as in silica organosols, or silanized (silylated) (Figure 14). Derivatization of the silica surface is the basis for the use of silica in analytical and process chromatography. 

The stability of carbenium ions deereases in the order tertiary>seeondary>primary, meaning that the yield of ethylene is generally much less than that of propylene. Zhang et al. found that by adjusting the acid type, aeid strength and aeid distribution, the ratio of ethylene to propylene ean be altered in favor of ethylene. A modified MFI t e zeolite PMZ was formed by treatment of ZRP-1 with alkaline earth metal ions. When PMZ is used as the eatalyst for middle distillate cracking at 520 °C, the ratio... 

Stability of an ion-exchanger at high pH may be important when alkaline clean-up washes are used to remove final traces of polypeptides or proteins, or the lipopoly-saccharides that are the major class of endotoxins. However, alternate, less harsh methods have been described to achieve this clean-up (see below). 

Uses Surfactant, emulsifier, solubilizer in detergent formulations for dry cleaning, chlorated detergents and degreasing agents for automotive parts emulsifier for hair dyes, permanents and bleaches, lotion, deodorants solubilizers for bath oils Features Moderate foaming power reduces surface tension does not precipitate in the presence of ions in hard water maintains chemical, physical stability in alkaline or acid environments compat. with non-ionic, anionic, cationic surfactants... 

Uses Scale inhibitor for cellulose and machine parts sequestrant and stabilizer for alkaline earth ions, esp. calcium ions emulsifier, stabilizer, pH control agent, raising agent, sequestrant, water retention agent in foods Regulatory BgW compliant... 

Ammonium chloride [12125-02-9], ammonium sulfate [7783-20-2], and diammonium phosphate [7708-28-0] have also been used for shale stabilization (102,103). Ammonium ions have essentially the same effect on shales as potassium ions but use of ammonium salts is often objectionable because of the alkaline nature of the mud. In the North Sea and northern Europe, where magnesium-bearing salt formations ate encountered, magnesium chloride [7786-30-3] is used, but in the United States it is used only on a small scale. 

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