Hexadecyltrimethylammonium salts

Quaternary ammonium periodates, prepared either from periodic acid and the quaternary ammonium hydroxide [21, 22] or by metathesis from sodium periodate and a quaternary ammonium salt [e.g. 23-25], have been used for a range of oxidations at stoichiometric levels in two-phase systems [21-33], The tetra-n-butyl-ammonium and hexadecyltrimethylammonium salts are both highly soluble in organic solvents (considerably less so in water), whereas benzyltriethylammonium periodate has a lower solubility and stability than either salt. 

J. Uhnius, B. Lindman, G. Lindblom, T. Drakenberg, H-l,C-13,Cl-35, and Br-81 NMR of aqneous hexadecyltrimethylammonium salt-solntions - solnbUization, viscoelasticity, and connterion specificity, J. Colloid Interface Sci., 1978, 65, 88-97. 

Hexadecyltrimethylammonium methyl sulfate. See Cetrimonium methosulfate Hexadecyltrimethylammonium, salt with 1,2-benzisothiazol-3(2H)-one 1,1-dioxide (1 1). See Cetrimonium saccharinate Hexadecyl trimethyl ammonium p-toluene sulfonate. See Cetrimonium tosylate Hexadenol. See 2,4-Hexadienol... 

FabreH,KamenkaN,KhanA,LindblSelf-diffusion and NMR studies of chloride and bromide ion binding in aqueous hexadecyltrimethylammonium salt solutirais. J Phys Chem 84 3428-3433... 

Chloride is bound by the sols formed upon the extensive hydrolysis of Al(III) salt solutions. Binding to liquid crystal systems is also studied and chloride and bromide bind to the micelles formed by hexadecyltrimethylammonium salts. The relaxation rate changes when the micelles change from spheres to rods and there is a marked difference between the behavior of the two ions. Many enzymes bind chloride and this may affect their activity. Thus horse liver alcohol dehydrogenase is stabilized by low concentrations of Cl which binds to two sites, neither of which is Zn. Phosphate ligands compete for the binding sites. Interaction between Zn ",... 

Micellar catalysis of azo coupling reactions was first studied by Poindexter and McKay (1972). They investigated the reaction of a 4-nitrobenzenediazonium salt with 2-naphthol-6-sulfonic and 2-naphthol-3,6-disulfonic acid in the presence of sodium dodecylsulfate or hexadecyltrimethylammonium bromide. With both the anionic and cationic additives an inhibition (up to 15-fold) was observed. This result was to be expected on the basis of the principles of micellar catalysis, since the charges of the two reacting species are opposite. This is due to the fact that either of the reagents will, for electrostatic reasons, be excluded from the micelle. 

Heterocyclic block copolymers, 282-284 Heterocyclic diamines, rigid, 281 Heterocyclic polymers, structure-property relationships in, 273-274 Heterocyclic ring formation, PQ and PPQ synthesis by, 309-310 Hexadecyltrimethylammonium bromide (HTMAB), 549-550 Hexamethylene diisocyanate (HDI), 199, 210. See also HDI trimer Hexamethylenediamine-adipic acid salt, 169, 170... 

Bromophenol blue sodium salt (water Hexadecyltrimethylammonium bromophenol ... 

DNA from those sources rich in polysaccharides can be purified by the addition of CTAB (hexadecyltrimethylammonium bromide) before chloroform isoamyl alcohol extraction [6], After adjusting NaCl concentration to 0.7 M with 5 M NaCl in a DNA solution solution (ca. 0.05 mg/mL in TE), CTAB solution (10% CTAB in 0.7 M NaCl) is added so that the final concentration of CTAB is about 1%. The samples are incubated at 65°C for 10 minutes. It is important to keep the salt at a concentration of greater than 0.5 M so that the DNA does not precipitate as a CTAB-DNA complex. After the addition of an equal volume of chloroform-isoamyl alcohol (24 1 by volume) and gentle but complete mixing, the phases are separated by centrifugation for 10 minutes at 2000 x g. The interphase will appear as a white precipitate of CTAB-polysaccharides/protein complex. The aqueous phase containing DNA is transferred with a wide-bore pipette to a tube, and the CTAB chloroform-isoamyl alcohol extraction can be repeated until no cellular material is visible at the interphase. The DNA from the aqueous phase is precipitated with ethanol as described earlier, and any residual CTAB is washed with 70% ethanol washes. 

This order is similar to the anion selectivity order found on a typical strongly basic anion exchanger. Figure 2(b) illustrates a separation of five inorganic anions with a 1.36 x 10 1M hexadecyltrimethylammonium chloride micellar mobile phase. No buffer salts or organic modifier were used in order to accomplish this separation. 

Relatively small retardations of the rate of the base catalyzed hydrolysis of methyl-1-naphthoate by sodium dodecylsulfate (NaLS) and hexadecyltrimethylammonium bromide (CTAB) in 50 wt percent dioxane-water have been observed. These effects were attributed to micelle formation in this solvent system since plots of In where 2 and are the second order rate constants in the presence and absence of the organic salts, vs. the concentration of the salts were non-linear... 

Comments the original cetrimide BP 1953 consisted largely of hexadecyltrimethylammonium bromide, with smaller amounts of analogous alkyltrimethylammonium bromides. It contained a considerable proportion of inorganic salts, chiefly sodium bromide, and was less soluble than the present product. 

Methanesulphonic acid (Na salt) Pentanesulphonic acid (Na salt) Hexanesulphonic acid (Na salt) Heptanesulphonic acid (Na salt) Oxtanesulphonic acid (Na salt) 2-Naphthalenesulphonic acid (Na salt) Dodecylsulphonic acid (Na salt) Tetrabutylammonium hydroxide Tetraethylammonium hydroxide Tetrabutylammonium phosphate Hexadecyltrimethylammonium bromide Trihexylamine Triheptylamine Trioctylamine... 

By emulsion polymerization of styrene with chloromethylated styrene in the presence of divinylbenzene and hexadecyltrimethylammonium bromide as a surfactant, latex particles of the copolymer were synthesized with a diameter of 0.08-0.2 m [67,68]. The copolymer was transformed directly to phosphonium salts by boiling the emulsion with tributylphosphine for 24 h. The stirring rate over 510-670 rpm did not affect the rate constants of catalyzed, interfacial transfer reactions of the aqueous solution of sodium cyanide with 1-bromooctane at 90 °C and with benzyl bromide at 80 °C in toluene in the presence of the above catalysts. The catalyst activity increased with an increase in the latex particle size. 

In addition, one-phase smfactant-assisted chemical method has been utilized to synthesize PANI nanofiber, which was doped with CSA and 2-acrylamido-2-methyl-l-propanesulfonic acid, in large quantities [291]. A chemical oxidative polymerization of aniline has been carried out using ammonium peroxydisulfate as an oxidizing agent in the presence of nonionic surfactant. A precipitate of doped emeraldine salt is composed of PANI nanofiber, which has the diameter of 30-50 nm and exhibits the conductivity of 1 -5 S cm at RT. Another piece of research has been done through chemical oxidation polymerization of aniline in a surfactant gel, which was formed by a mixture of hexadecyltrimethylammonium chloride, acetic acid, anihne, and water at - 7 °C [292]. The dendritic PANI nanofiber has the diameter of 60-90 nm and the length of 1 -2 jim. Extended works have been performed by the electrospinning method [293]. It should be taken into account that PANI-CSA fiber shape could be influenced by the synthetic variables such as solvent, surface tension, viscosity, and solution conductivity. 

The use of onium salts containing both long and very short alkyl chains, such as hexadecyltrimethylammonium bromide, will promote stable emulsions in some reaction systems, and thus these are poor catalysts. They remain popular, however, as their surfactant and biocide applications make them cheap and readily available. 

Mix equal volumes of 0.001 M hexadecyltrimethylammonium bromide and sodium pentane-l-sulphonate to form salt which is anionic surfactant-selective. 

Hexadecylpyridinium chloride 1-Hexadecylpyridinium chloride n-Hexade-cylpyridinium chloride. See Cetylpyridinium chloride Hexadecyl sodium sulfate. See Sodium cetyl sulfate Hexadecyl stearate n-Hexadecyl stearate. See Cetyl stearate Hexadecyl (sulfophenoxy) benzenesulfonic acid, disodium salt See Sodium hexadecyl diphenyl disulfonate Hexadecyl tetradecanoate. See Cetyl myristate Hexadecyltrimethylammonium bromide. See Cetrimonium bromide Hexadecyl trimethyl ammonium chloride. See Cetrimonium chloride Hexadecyl trimethyl ammonium p-toluene sulfonate. See Cetrimonium tosylate Hexadienic acid Hexadienoic acid 2/4-Hexadienoic acid. See Sorbic acid 2/4-Hexadienoic acid potassium salt. See Potassium sorbate Hexaethylene glycol. See PEG-6... 

An electrode sensitive to both cationic and anionic surfactants can be made from a glass tube sealed at the bottom with a membrane of poly(vinylchloride) containing a high percentage of plasticizer, 40% or more. Dissolved in the plasticized PVC is a surfactant ion pair, such as hexadecyltrimethylammonium dodecylsulfate. The tube is filled with a dilute solution of anionic surfactant with a small amount of a chloride salt, into which a silver/ silver chloride electrode is inserted. For potential measurements in solutions, the circuit is completed with a reference electrode such as saturated calomel. Commercial surfactant-selective electrodes based on PVC membranes have been available since approximately 1990. 

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