Ammonium decanoate

Burkitt et al. [56] investigated the size and shape of micelles of ammonium salts of octanoic, decanoic, and perfluorooctanoic acids by SANS. Ammonium octanoate and ammonium decanoate formed spherical micelles having a micellar weight of 1640 and 12,576, respectively. Ammonium perfluorooctanoate formed cylindrical micelles with a mean micellar weight of 17,610. This corresponded to a mean association number of 43 at 0.12M. Burkitt at al. proposed a cylindrical micelle in which the head groups are hexagonally close-packed and the fluorocarbon chains form helical rows (Fig. 7.3). 

Burkitt et al. [92] studied mixtures of ammonium decanoate (AmDec) and ammonium perfluorooctanoate (APFO) by the contrast matching SANS technique [56]. The proportions of the two surfactants in an ammonium chloride-ammonium hydroxide buffer at pH 8.8 and an ionic strength of 0.1 were varied. The mixed micelles formed were cylindrical in shape at APFO/AmDec ratios of 2 1, 1 1, and 1 2. The micelle appeared to have a diameter of 20 A and a length of 150 A. The authors proposed that the original ammonium perfluorooctanoate micelle, which also had a diameter of 20 A, expanded along the lateral axis to accommodate the decanoate chains (Fig. 7.8). At a 1 9 APFO/AmDec ratio, the micelles were found to be cylindrical but larger than those formed by ammonium decanoate alone. 

The SANS external contrast-matching technique (see Section 9.10) was employed also by Caponetti et al. [89], who concluded that a mixture of sodium per-fluorooctanoate and sodium decanoate form mixed micelles having the same composition and a very narrow size distribution. Clapperton et al. [94] examined binary mixtures of ammonium perflurooctanoate and ammonium decanoate by a combination of H- and F-NMR spectroscopy. The mixtures were buffered at pH 9.0 in NH4OH-NH4CI solutions at an ionic strength of 0.1. The chemical shift data indicated nonideal, unfavored mixing of the hydrocarbon and fluorocarbon surfactants in the micelle. 

Burkitt et al. [228,229] used SANS to examine the size and shape of micelles in solutions containing ammonium perfluorooctanoate or mixtures of ammonium perfluorooctanoate with ammonium decanoate. The SANS measurements were made by the external contrast variation technique using mixtures of water and D2O as the solvent. By selecting appropriate H2O-D2O ratios, it is possible to view hydrocarbon and fluorocarbon micelle species independently. At a match point, the scattering length density of the H2O-D2O mixture is equal to that of the surfactant and the surfactant is at zero contrast. If the surfactants in a binary mixture form separate micelles, two match points are found. If mixed micelles are formed, scattering would occur at the contrast match points for each surfactant, but another match point is found as well. 

Burkitt et al. [228,229] concluded that SANS is an excellent method for the determination of micellar weights of ammonium octanoate, ammonium decanoate, and ammonium perfluorooctanoate. The scattering data suggested that the ammonium perfluorooctanoate micelles are cylindrical. 

Triglycerides in pharmaceutical formulation including testosterone phenyl propionate, testosterone propionate, testosterone isocaproate, testosterone decanoate Hypersil ODS, 3 pm Acetonitrile-isopropanol-n-hexane (57 38 5) 50 mM ammonium acetate 250 mm x 100 pm i.d. 52... 

In the extraction of Mn(II) from ammonium chloride solution with decanoic acid benzene, Bartecki et al. (11) reported that the prevailing species in the organic phase was a dimeric complex, Mn2A4(HA)4, in addition to a small amount of tri- and tetramers. The monomeric extracted species MnA2(HA)2, found in decane (39), seems unlikely. 

The dynamics of mixtures of surfactants with proteins is of great importance for many practical processes, such as coating of photographic films, where gelatine in mixtures with surfactants and surface active dyes adsorb at the interface. Hempt et al. (1985) studied the relaxation behaviour of gelatine solutions in presence and absence of surfactants (SDS, tetradecyl dimethyl phosphine oxide, cetyltrimethyl ammonium bromide, n-decanoic acid, perfluoro octanoic acid tetraethyl ammonium salt). 

Alcohols, Cl6-18, ethoxylated. SeeCeteareth Alcohols, Cl6-18, ethoxylated, phosphates, bis(2-hydroxyethyl) ammonium salts (2 EO). See DEA-ceteareth-2 phosphate Alcohols, C11-14-iso-, C13-rich. SeeC11-14-isoalcohols Cl 3-rich Alcohols, coco. See Coconut alcohol Alcohols, coco, mixed esters with octanoic and decanoic acids. See Coco caprylate/caprate Alcohols, coco, sulfated, magnesium salt (2 1). 

Pedersen reported in 1967 that the dicyclohexyl-18-crown-6 complex of potassium hydroxide was soluble in toluene and in this medium could readily hydrolyze the very sterically hindered ester methyl mesitoate [33]. He later reported that this complex could also hydrolyze the tertiary-butyl ester [34]. Similarly, Lehn found that the [2.2.2]-cryptate complex of potassium hydroxide was even more effective in this saponification reaction under directly comparable conditions [35]. The hydrolysis reaction is formulated in equation 9.15. This method has recently been applied in the hydrolysis of C-labelled methyl tetradecanoate [36]. Starks found that tetra-decanoate anion acted as a catalyst poison and impeded further hydrolysis [7]. This is therefore one of the few examples where crown ether catalysis is clearly superior to quaternary ammonium ion catalysis. 

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