Tetradecyltrimethylammonium

Figure C2.3.17. Model of half-cylindrical aggregates (hemimicelles) on a crystalline hydrophobic substrate, such as for tetradecyltrimethylammonium bromide on M0S2 [91], Adapted from figure 2 of [89],...

Tetradecyltrimethylammonium bromide [1119-97-7] M 336.4, m 244-249 . Crystd from acetone or a mixture of acetone and >5% MeOH. Washed with diethyl ether and dried in a vacuum oven at 60°. [Dearden and Wooley J Phys Chem 91 2404 1987.]... 

Tarek et al. [388] studied a system with some similarities to the work of Bocker et al. described earlier—a monolayer of n-tetradecyltrimethylammonium bromide. They also used explicit representations of the water molecules in a slab orientation, with the mono-layer on either side, in a molecular dynamics simulation. Their goal was to model more disordered, liquid states, so they chose two larger molecular areas, 0.45 and 0.67 nm molecule Density profiles normal to the interface were calculated and compared to neutron reflectivity data, with good agreement reported. The hydrocarbon chains were seen as highly disordered, and the diffusion was seen at both areas, with a factor of about 2.5 increase from the smaller molecular area to the larger area. They report no evidence of a tendency for the chains to aggregate into ordered islands, so perhaps this work can be seen as a realistic computer simulation depiction of a monolayer in an LE state. 

Fig. 3. Possible arrangements of long-chain quaternary ammonium cations (here tetradecyltrimethylammonium) in the interlayer space of expanding 2 1 layer silicates. After Lagaly (1982) and Jaynes and Boyd (1991a).

Fig. 9. Growth of phenanthrene-degrading bacteria (Burkholderia sp. RP007) in the presence of either phenanthrene in the free form (A), or phenanthrene intercalated into tetradecyltrimethylammonium (TDTMA)-montmorillonite (B). After Theng et al. (2001).

Other cationic surfactants such as TTAB, DTAB, DODAB, STAC, CEDAB, and DDDAB have been used in CL reactions with less frequency. Thus, tetradecyltrimethylammonium bromide [TTAB] has been used to increase the sensitivity of the method to determine Fe(II) and total Fe based on the catalytic action of Fe(II) in the oxidation of luminol with hydrogen peroxide in an alkaline medium [47], While other surfactants such as HTAB, hexadecylpiridinium bromide (HPB), Brij-35, and SDS do not enhance the CL intensity, TTAB shows a maximum enhancement at a concentration of 2.7 X 10 2 M (Fig. 11). At the same time it was found that the catalytic effect of Fe(II) is extremely efficient in the presence of citric acid. With regard to the mechanism of the reaction, it is thought that Fe(II) forms an anionic complex with citric acid, being later concentrated on the surface of the TTAB cationic micelle. The complex reacts with the hydrogen peroxide to form hydroxy radical or superoxide ion on the... 

C14H29NMe3 Br Tetradecyltrimethylammonium bromide Myristyryltrimethylammonium bromide, MTABr 3.5 x 1(T3... 

A wide choice of cationic surfactants such as CTAB (cetyltrimethylammonium bromide), CTAH (cetyltrimethylammonium hydroxide), TTAB (tetradecyltrimethylammonium bromide), TTAOH (tetradecyltrimethylammonium hydroxide), MTAB (myristyltrimethylammo-nium bromide), OFM (OFM Anion-BT, Waters, Milford, MA, USA), HDB (hexadimethrine bromide), and many others may be used to reverse the EOF. CTAH and TTAOH should be preferred to CTAB and TTAB to avoid interference from bromate contamination. The capillary coating is performed just by rinsing with the BGE containing this flow modifier or even with an additional rinse step with a solution containing this flow modifier. 

K. Hayakawa, J.P. Santerre, and J.C.T. Kwak Study of Surfactant-Polyelectrolyte Interactions. Binding of Dodecyl-and Tetradecyltrimethylammonium Bromide by Some Carboxylic Polyelectrolytes. Macromolecules 16, 1642 (1983). 

Wilhemy plate, 633-635, 641-642 Tension, see Interfacial tension Tetradecyltrimethylammonium bromide... 

Fig. 5. An analysis of a coarse atmospheric aerosol extract by CE and IC [49]. CE conditions a 57 cmX75 xm I.D. capillary, distance to detector, 50 cm. Electrolyte 2.25 mM PMA (pyromel-litic acid), 0.75 mM HMOH (hexamethonium hydroxide), 6.50 mM NaOH and 1.60 mM TEA (triethanolamine), pH 7.7 or 2.0 mM NDC (2,6-naphthalenedicarboxylic acid), 0.5 mM TTAB (tetradecyltrimethylammonium bromide) and 5.0 mM NaOH, pH 10.9 30 kV (PMA) or 20 kV (NDC) pressure injection for 10 s indirect UV detection at 254 nm (PMA) or 280 nm (NDC). IC conditions an IonPac-ASlO column with an IonPac-AGlO guard precolumn conductivity detection using an anion self-regenerating suppressor (ASRS-I) in the recycle mode. Analytes 2, chloride 3, sulfate 5, nitrate 6, oxalate 7, formate 10, hydrocarbonate or carbonate 11, acetate 12, propionate 14, benzoate.

Formation of the Sic Phase in Binary Aqueous Alkyltrimethylam-monium Halide Solutions. These considerations are well illustrated by the formation of the Slc phase in aqueous alkyltrimethylammonium halide solutions (17) (Figure 7). This phase is apparently composed of Si micelles—probably on balance prolate—arranged in a primitive, cubic lattice and rotating fairly freely at the lattice points. The lattice is formed by dodecyl- and tetradecyltrimethylammonium chlorides but not by the hexadecyl or octadecyl chlorides nor by any of the corresponding bromides. This may be expressed as follows. 

FIGURE 2.3 51V NMR spectrum of vanadate in a nematic lyotropic liquid crystalline solution. The spectrum shows quadrupole-split signals from V and V4, while the signal of V2 is broadened. The quadrupole splittings are 200 Hz and 5.35 kHz for V and V4, respectively. The spectrum was obtained from a tetradecyltrimethylammonium bromide (TDTMABr) mesophase of composition TDTMABr, 160 mg decanol, 30 mg D20,450 mg NaCl, 10 mg. 

A capillary electrophoresis method was described for EDTA in spent fixing solutions [88]. After complexation with Ni(II), separation is effected using a fused silica capillary (57 cm x 75 pm i.d) filled with borate buffer containing 0.1 mM pH 8.5 tetradecyltrimethylammonium hydroxide. The applied voltage was -30 kV, and detection was effected at 214 nm. 

It has been shown that the addition of a small amount of the anionic surfactant sodium dodecyl sulfate (SDS) to a microemulsion based on nonionic surfactant increased the rate of decyl sulfonate formation from decyl bromide and sodium sulfite (Scheme 1 of Fig. 2) [59,60]. Addition of minor amounts of the cationic surfactant tetradecyltrimethylammonium gave either a rate increase or a rate decrease depending on the surfactant counterion. A poorly polarizable counterion, such as acetate, accelerated the reaction. A large, polarizable counterion, such as bromide, on the other hand, gave a slight decrease in reaction rate. The reaction profiles for the different systems are shown in Fig. 12. More recent studies indicate that when chloride is used as surfactant counterion the reaction may at least partly proceed in two steps, first chloride substitutes bromide to give decyl chloride, which reacts with the sulfite ion to give the final product [61]. 

The effects of dodecyltrimethylammonium bromide and chloride, tetradecyltrimethylammonium bromide, CTAB, and NaLS on the dissociation constants of 20a and 20c were investigated by Mukerjee and Banerjee (1964), and the differences between the bulk and the micellar surface pK s of the indicators were interpreted in terms of the electrical potential difference and changes in the pX. Thus, the higher pK at the surface of the cationic micelles as compared to that in the bulk solution can be attributed to a lower effective dielectric constant at the micelle surface. 

SDS sodium dodecyl sulfate HDTC1 hexadecyltrimethylammonium chloride HDTBr hexadecyltrimethylammonium bromide Brij 35 polyoxyethylene (23) lauryl ether DTAC dodecyltrimethylammonium chloride TTAC1 tetradecyltrimethylammonium chloride HDPB hexadecylpyridinium bromide KDC potassium decanoate SPFO sodium perfluorooctanoate KTC potassium tetradecanoate... 

Consists chiefly of tetradecyltrimethylammonium bromide together with smaller amounts of dodecyl- and hexadecyltri-methylammonium bromides. 

Tetracycline hydrochloride, 1005 Tetracycline methylenelysine, 714 Tetradecyltrimethylammonium bromide, 439 Tetraethylammonium bromide, xvii Tetraethylthiuram disulphide, 566 Tetraethylthiuram monosulphide, 788 Tetrafluorodichloroethane, 532 Tetrahydroacridinylamme, 1000 Tetrahydroaminacrine, 1000 A -Tetrahydrocannabinol, 424 A -Tetrahydrocannabinol, 423 Tetrahydrocannabinolic acid, 424 Tetrahydrocannabinoloic acid, 425 Tetrahydrocannabivaric acid, 217 Tetrahydrocannabivarin, 217 Tetrahydrocortisol, 666 Tetrahydrocortisone, 666... 

Effects of addition of n-tetradecyltrimethylammonium bromide (C14TAB) on the micelle-monomer exchange processes of /f-decyltrimethylammonium bromide (CioTAB) were investigated by the ultrasonic relaxation method. The relaxation frequency increased and the relaxation strength decreased with increasing amount of CuTAB added. The dependence of the relaxation frequency on the amount of CuTAB added was in fair agreement with the relaxation theory of Annianson for mixed micelle... 

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