Quarternary ammonium compounds

Cationic, anionic, and amphoteric surfactants derive thek water solubiUty from thek ionic charge, whereas the nonionic hydrophile derives its water solubihty from highly polar terminal hydroxyl groups. Cationic surfactants perform well in polar substrates like styrenics and polyurethane. Examples of cationic surfactants ate quaternary ammonium chlorides, quaternary ammonium methosulfates, and quaternary ammonium nitrates (see QuARTERNARY AMMONIUM compounds). Anionic surfactants work well in PVC and styrenics. Examples of anionic surfactants ate fatty phosphate esters and alkyl sulfonates. 

The anion associated with quarternary ammonium compounds can influence markedly the stereochemical outcome of hydrogenolysis (43bJ67a). 

Mucin, a viscous mucopolysaccharide that lines and protects the intestinal epithelium, has been thought to bind certain drugs nonspecifically (e.g., quarternary ammonium compounds) and thereby prevent or reduce absorption. This behavior may partially account for the erratic and incomplete absorption of such charged... 

Effect on CNS Acetylcholine when injected parenterally does not cross blood brain barrier being a quarternary ammonium compound and does not have any central action. 

Rare earths Various mixed solutions Different processes involving 2DEHPA, TBP, tertiary carboxylic acids, quarternary ammonium compounds, etc. 

Acetylcholine [a se teel KOE leen] is a quarternary ammonium compound that cannot penetrate membranes. Although it is the neurotransmitter of parasympathetic and cholinergic nerves, it is therapeutically of no importance because of its multiplicity of actions and its rapid inactivation by acetylcholinesterase. Acetylcholine has both muscarinic and nicotinic activity. Its actions include ... 

Bacitracin zinc in pharmaceutical preparations New approach to quarternary ammonium compounds Pharmacology of choline theophylllinate Methemoglobinemia resulting from absorption of nitrates (From RefJ. )... 

Other potential contaminants are, however, less obvious and these include lubricants (e.g., silicone grease), plasticizers (e.g., phthalates, phenyl phosphates, sebacates, and bisphenol A), slip agents (e.g., oleamide, erucamide, and stearamide), biocides (e.g., quarternary ammonium compounds) and polymers extracted from laboratory consumables (e.g., silicones from laboratory tubing) and membrane filters (e.g., cyclic oligomers and Nylon 66).168 169... 

Retarders (quarternary ammonium compounds, nonionic surfactants) Surfactants ... 

Once deposits are removed and the surface is visibly clean, it is time to sanitize. Choices for chemical sanitizing agents include the halogens, chlorine and iodine, as well as quarternary ammonium compounds (QUATS). Table 7-1 compares sanitizers with respect to their relative merits and deficiencies. 

Dery, M., Quarternary ammonium compounds, in Kirk Othmer Encyclopedia of Chemical Technology, 4th ed., vol. 20, Wiley, New York, 1997. 

Hypochlorite salt Cyanuric acid T richoro-S triazenetrione Alkalinization agents and pH stabilizers Sodium carbonate Sodium bicarbonate Sodium bisulfate Algaecide components Elemental copper Copper sulfate Quarternary ammonium compounds... 

Long-chain quarternary ammonium compounds (QACs) are cationic surface active agents according to the general formula... 

Methionine differs from the other methyl donors in being a simple thioether, whereas the others are sulfonium compounds or quarternary ammonium compounds. Onium compounds with an anionic group appear to be the only methyl donors choline, an onium compound, is inert as a donor until it is oxidized to betaine. Methionine was found to transfer its methyl group only in the presence of ATP. Cantoni has... 

Ethoguard Armour Hess Chem. Ltd., UK Quarternary ammonium compounds... 

Although plastics are usually immune to bacterial attacks there is an exception in the case of plasticised PVC where the plasticiser is susceptible to such attack. The majority of bacteriocidal agents used in polymer formulations are quarternary ammonium compounds. 

The heats of solution data in nonaqueous-aqueous solvents are arranged alphabetically by nonaqueous component. Within each solvent table the electrolytes are listed alphabetically by chemical formulae, except for the quarternary ammonium compounds which are given according to increasing chain length. Values of standard heats of solution at infinite dilution, heats of solution for a particular concentration and heats of dilution are included wherever possible. A complete bibliography is given at the end of section V(c). 

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