Surface active cations

Soaps of heavy metals have been used but cationic surface-active agents have proved more suitable, notably organic amines of relatively high molecular weight. 

These oxazolines have cationic surface-active properties and are emulsifying agents of the water-in-oil type. They ate acid acceptors and, in some cases, corrosion inhibitors (see Corrosion). Reaction to oxazoline also is useful as a tool for determination of double-bond location in fatty acids (2), or for use as a protective group in synthesis (3). The oxazolines from AEPD and TRIS AMINO contain hydroxyl groups that can be esterified easily, giving waxes (qv) with saturated acids and drying oils (qv) with unsaturated acids. 

Cationic surface-active agents promote wetting of the sulfur and thereby increase the reaction rate (36). The quahty of the product is improved by using photographic-grade sodium sulfite or bisulfite. Excess sulfur is filtered before evaporation (qv) and crystallization (qv). Evaporation is energy-intensive thus it is important to produce the thiosulfate solution at the highest possible concentration. The purity of the product is typically >99% sulfite and sulfate ate the main impurities. 

Surface-active agents iacrease the conductivity of oils quite significantly (97), and addition of water, probably dissolved at the iaterface with the surfactant, further iacreases the conductivity. Nonionic and cationic surface-active agents are preferred to anionic surface-active agents probably because of their higher solubiHty ia oils and higher hygroscopicity. Many anionic surfactants have adequate antistatic efficiency, but they are used less frequendy. 

Benzyl-derived quaternary ammonium compounds are used widely as cationic surface-active agents and as germicides, fungicides, and sanitizers. Benzyl alcohol is used in a wide spectmm of appHcations including pharmaceuticals and perfumes, as a solvent, and as a textile dye assistant. 

In presence of polyamines the maximum of light absorption of indicated triphenylmethane dyes displaces on 10-30 nm, for azo dyes the shift of the band reaches 50-80 nm. The greatest difference of light absorption of associates and reagents is watched for BKM at pH 5,05, for BPR at pH 4,20, for CPR in an interval pH 5,05-5,45. At these pH dyes are anions, it promotes interaction with a cationic surface-active substance. The ratios between polymer and BKM, BPR, CPR are established by spectroscopy method, its equal 1 20, 1 20 and 1 30 accordingly. 

These general observations have been confirmed in PAMPA measurements in our laboratory, using the 2% DOPC-dodecane lipid. With very lipophilic molecules, glycocholic acid added to the donor solution slightly reduced permeabilities, taurocholic acid increased permeabilities, but SLS arrested membrane transport altogether in several cases (especially cationic, surface-active drugs such as CPZ). 

Spectrophotometric methods have found fairly extensive applications but are limited in sensitivity and specificity (cationic surface active agents,... 

Simms etal. [8] discuss the quantitative determination of cationic surface active agents at the sub-ppb level in sewage sludges using fast atom bombardment mass spectrometry. 

Baleux, B. and Caumette, P. (1977) Biodegradation of some cationic surface-active agents. Water Res., 11, 833-841. 

LAURYL PYRIDINIUM CHLORIDE is a cationic surface active agent which is used as a dispersing and wetting agent to keep spinnerettes clean in the manufacture of viscose rayon. In the textile industry it is used as a stripping agent for vat and other dyes. 

Quaternary ammonium compounds are surface-active agents. Some of them precipitate or denature proteins and destroy microorganisms. The most important disinfectants in this group are cationic surface-active agents, such as benzalkonium chloride, benzethonium chloride and methylbenzethonium chloride, and cetylpyridinium chloride the problems that they cause are similar. 

L. K. Wang, Cationic surface active agent as bactericide. Industrial and Engineering Chemistry, Product Research and Development, 14(4), 308-312 (1975). 

Use Curing agent for polyurethane foams, intermediate for cationic surface-active agents. Note Two other isomers are available, cis-2,5- and trans-2,5- neither is flammable, but both are combustible. 

Octadecyldimethylbenzyl ammonium chloride and hexamethonium chloride are examples. Pentavalent nitrogen ring compounds, such as lauryl pyridinium chloride, are also considered quaternary ammonium compounds. They are all cationic, surface-active... 

Use Intermediate for manufacture of cationic surface-active agents, germicides. 

Some of these are products known as Fixanol C, Sandofix WE, Lyofix EW, and Tinofix. They are cationic surface-active compounds which unite with the dye anion, producing a more complex molecule w hich has better wet-fastness. The use of these compounds does, however, tend to reduce light-fastness. The chemical constitution of Fixanol C and the nature of its action are described in Chapter 9. 

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