Dodecyl trimethylammonium

The physical meaning of the g (ion) potential depends on the accepted model of an ionic double layer. The proposed models correspond to the Gouy-Chapman diffuse layer, with or without allowance for the Stem modification and/or the penetration of small counter-ions above the plane of the ionic heads of the adsorbed large ions. " The experimental data obtained for the adsorption of dodecyl trimethylammonium bromide and sodium dodecyl sulfate strongly support the Haydon and Taylor mode According to this model, there is a considerable space between the ionic heads and the surface boundary between, for instance, water and heptane. The presence in this space of small inorganic ions forms an additional diffuse layer that partly compensates for the diffuse layer potential between the ionic heads and the bulk solution. Thus, the Eq. (31) may be considered as a linear combination of two linear functions, one of which [A% - g (dip)] crosses the zero point of the coordinates (A% and 1/A are equal to zero), and the other has an intercept on the potential axis. This, of course, implies that the orientation of the apparent dipole moments of the long-chain ions is independent of A. 

Ethoxylated methylcarboxylates Propoxyethoxy glyceryl sulfonate Alkylpropoxyethoxy sulfate as surfactant, xanthan, and a copolymer of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate Carboxymethylated ethoxylated surfactants (CME) Polyethylene oxide (PEG) as a sacrificial adsorbate Polyethylene glycols, propoxylated/ethoxylated alkyl sulfates Mixtures of sulfonates and nonionic alcohols Combination of lignosulfonates and fatty amines Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride Anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonylphenol (NP-15), and nonionic octaethylene glycol N-dodecyl ether Dimethylalkylamine oxides as cosurfactants and viscosifiers (N-Dodecyl)trimethylammonium bromide Petrochemical sulfonate and propane sulfonate of an ethoxylated alcohol or phenol Petrochemical sulfonate and a-olefin sulfonate... 

This paper describes a study of the dispersibility of Graphon (graphitized Spheron 6) in aqueous solutions of sodium dodecyl sulfate (SDS) an dodecyl trimethylammonium bromide (DTAB), and its relation to the adsorption behavior of the surfactants at the solid/liquid interface, with a view to determine the controlling process in the dispersibility of these systems. 

None of the poly-amino acids were found to be very soluble in any of the above mixtures. DGK3M was observed to be partially, but incompletely soluble in the SDS, dodecyl trimethylammonium, and octyl glucoside mixtures. The general difficulty of solubilizing these polypeptides in traditional denaturant and detergent solutions may reflect the inability of the solutions to overcome a kinetic barrier to disaggregation and should not necessarily be taken to imply thermodynamic instability of the fiiUy dispersed proteins in the solutions. 

We turn now to the temperature dependence of the cmc. Eqn (6.1) gives little indication of how the cmc should vary with temperature. The observed cmcs all have a minimum between 20-30°C, for sodium n-dodecyl, n-decyl and 2-decyl sulphates, and for n-dodecyl trimethylammonium bromide. While the temperature dependence of the term lyaojkT could be estimated from data on the surface tension of water and decreases with temperature, we have no information on the temperature dependence of the hydrophobic term g—g. However, evidenceon the solubilities and enthalpy of solution of the sequence ethane, propane, butane,... 

Average value obtained using 2,6-diphenyl-4-(2,4,6-triphenyl-l-pyridinio)phenoxide, 1-hexadecyl-4-[(oxocyclohexadienylidene)ethylidene]-l,4-dihydropyridine, l-hexadecyl-5-hydroxyquinoline and l-hexadecyl-6-hydroxyquinoline, average deviation <9 % calculated from [47d]. Abbreviations SDS = sodium dodecyl sulfate DBS = dodecyl benzenesulfonate CTAC = hexadecyltri-methylammonium chloride CTAB = hexadecyltrimethylammonium bromide DTAC = dodecyl-trimethylammonium chloride DTAB = dodecyltrimethylammonium bromide DHP = dihexadecyl phosphate DDDAB = didodecyldimethylammonium bromide DMPC = dimyristoylphosphati-dylcholine DPPC = dipalmitoylphosphatidylcholine POPC = l-palmitoyl-2-oleoylphosphati-dylcholine PCA = phosphatidic acid. 

Samples of the nonionic and zwitterionic surfactants used were prepared in this laboratory and had a purity better than 99.5%. Sodium dodecyl sulfate was a sample prepared and purified in this laboratory. No minimum in the surface tension was found near the CMC. The dodecyl trimethylammonium bromide was a sample from Palmer Research Co. Ltd., showing a minimum of about 1 mNm 1 at the CMC. Water distilled from alkaline permanganate was used to prepare all solutions. All experiments were done at 25 °C where water had a surface tension of 72.25 mNm-1. 

Figure 6. Dependence of extrapolated dilational modulus, e0, on surface pressure tt for equimolar mixture of sodium dodecyl sulfate and dodecyl trimethylammonium bromide. Drawn line predicted curve for RT In f/...

Through the sol—gel process, single oxides such as silica can he synthesized with an organically modified surface, as well as double or triple oxides [9] such as Si— Al, Si—Ti, Si—Zr, A1—Zr, A1—Ti, and A1—Ti—Zr. For such syntheses, 1,10-diaminedecane and 1,12-diaminedodecane, as well as a surfactant such as dodecyl-trimethylammonium bromide, can be used, with the final modified oxides exhibiting lamellar or hexagonal nanostructure. Such compounds with modified surface are also able to coordinate transition metal cations. 

At an equal interfacial covering of surfactants the mass transfer of acetate is enhanced by a cationic surfactant (dodecyl trimethylammonium chloride, DTACl), unaffected by a nonionic surfactant (octylpolyethylene glycolether, TX100)io and slowed down by an anionic surfactant (sodium lauryl sulfate, NaLS sodiumdodecyl sulfate, NaDdS). This can be quantified when calculating the true interfacial concentrations, mpo,, in the electrochemical double layer with the Boltzmann equation ... 

The first situation is encoimtered when an anionic solute is eluted with an anionic surfactant, or a cationic solute is eluted with a cationic surfactant [e.g., dissociated phenol with the anionic surfactant sodium dodecyl sulfate (SDS), and protonated benzylamine with the cationic surfactant dodecyl trimethylammonium bromide (DTAB), on a C18 column] [2]. Electrostatic repulsion from the micelle should not affect the retention as the solute will still reside in the bulk solvent phase, and therefore, will move down the column. In contrast, repulsion from the surfactant-modified stationary phase should cause a decreased retention, and the solute may elute in the dead volume. However, it may be retained by hydrophobic interaction with the stationary phase, although this effect will be reduced by the electrostatic repulsion. Because due to different hydrophobic interactions, dissociated phenol and 2-naphthol are well separated with SDS. 

Ascorbic acid -i- 820 " 0.8-6 In a micellar medium (dodecyl-trimethylammonium bromide)... 

When the concentration of the added electrolytes is very high, the cmc values are decreased to values close to those of surfactants which are either zwitteripnic or nonionic. For example, at 25 °C, the cmc is 1.5 mM for n-dodecyl trimethylammonium ion in 0.5 M NaBr, 2.4 mM for n-dodecyl betaine, and 2.0 raM for n-dodecyl dimethyl amine oxide. 

Kwak and his team have carried out a good amount of work on the interaction of anionic polymer with cationic surfactant under different conditions, such as added salt concentration, salt type, and temperature (Hayakawa and Kwak 1982,1983 Hayakawa et al. 1983 Malovikova et al. 1984 Shimizu et al. 1986). For instance, Hayakawa and Kwak (1982) studied the interaction of dodecyl-trimethylammonium bromide (DTAB) with two anionic polymers sodium polystryrenesulfonate (NaPS) and sodium dextran sulfate (NaDxS). In an isothermal condition, they found that the interaction of DTAB with NaPS begins at a lower concentration as compared with the DTAB/NaDxS system due to a higher hydrophobicity of NaDxS. 

Fig. 11. Cylindrical self-organized phase with fee undulations in the structure, as suggested for the polyacrylic acid/dodecyl trimethylammonium complex. Adapted from M. Antonietti, C. Burger, J. Conrad, and A. Kaul, Macromol. Symp. 106,1 (1996).

Fig. 6. Comparison of experimental and model C - D order parameters (with respect to the local normal of the aggregate) for roughly spherical micelles at 40 °C. , results derived from T NMR relaxation measurements on dodecyl-trimethylammonium chloride (DOTAC) at 30 wtVo by Wal-derhaug et al. [3].---, model results assuming a spher-...

The effectiveness of gemini surfactants in lowering the surface tension of water is close to that of the corresponding monomeric surfactant. Indeed, the values of the surface tension at the CMC, ycMc, are close for monomeric and gemini surfactants, as illustrated by the results shown in Fig. 3 for 12-3-12, 2Br [4] and its corresponding monomeric surfactant, dodecyl-trimethylammonium bromide (DTAB) [72]. However, the former are always more efficient surface-active agents than the latter because their CMCs... 

Surfactant cations are difficult to displace from the clay mineral surface. Quaternary alkylammonium ions are easier to exchange than primary alkylammonium ions. Primary alkylammonium ions are removed by hydrolysis into the amine in alkaline medium [47]. The mutual exchange of surfactants in non-aqueous dispersions was studied by Me Atee [48, 49], Solvent was a mixture of isooctane and isopropyl alcohol. The alcohol served two functions as a solvent for the surfactant chloride salts and the dispersing agent for the clay mineral surfactant particles. An effective agent to displace quaternary alkylammonium ions (dodecyl trimethylammonium ions) is paraquat [50],... 

Dror and Manassen hydrogenated a- and cyclic olefins such as 1-octene, 1 -dodecene and cyclohexene in micellar systems using rhodium catalysts modified with water-insoluble carboxylated tenside phosphines 45 (Table 3 n=3,5,7,9,l 1) in the presence of conventional tensides such as sodium dodecylsulfate (SDS) or cetyltrimethylammonium bromide (CTAB) and cosolvents e.g. dimethyl sulfoxide. Linear olefins were more reactive than cyclic olefins. Maximum efficiency was observed in the presence of the anionic surfactant SDS when 45 contained a chain of 5-7 carbon atoms. In contrast, using the cationic tenside CTAB the ligand 45 with 5 C atoms was almost inactive but became active again with dodecyl trimethylammonium bromide. 

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