Cetyl hydrate

Cetyl hydrate—Cetylio alcohol—CieHasOH—242—is obtained by the saponification of spermaceti (its palmitic ether). It is a white, crystalline solid fusible at 49° (120°. 2 F.) insoluble in HaO soluble in alcohol and ether tasteless and odorless. 

Surfactants such as sulfated fatty alcohols may be hydrated to a higher extent than the fatty alcohols alone and thus stabilize o/w emulsions. The eombination of an anionic and a nonionic srrrfactant has proved to be partieularly effeetive, sinee the electrostatic repulsion forces between the ionie surfaetant moleeules at the interface are reduced by the incorporation of nonionic molecules, thus improving the emulsion stability. The combination of cetyl/stearyl sulfate (Lanette E) and eetyl/ stearyl alcohol (Lanette 0) to yield an emulsifying eetyl/stearyl aleohol (Lanette N) is an example of this approach. The polar properties of this srrrfactant mixtrrre are dominant, and o/w creams are formed. In contrast to w/o systems, the stabilizing effect of the surfactant mixtirre is not mainly due to adsorption at the interfaee. Instead, the mixed surfactants are highly hydrated and fonn a lamellar network, whieh is... 

Nonloaded and loaded SLN were already investigated with respect to use in cosmetics. Although adequate controls are difficult to prepare, first experiments indicate an increase in skin hydration and a reduction in wrinkle depth following SLN application [68]. Moreover, cetyl palmitate-nanodispersions act both as particulate ultraviolet (UV) blockers themselves and as carriers for UV absorbing agents (e.g., 2-hydroxy-4-methoxy benzophenone Eusolex 4360). This results in a threefold... 

This bimodal dynamics of hydration water is intriguing. A model based on dynamic equilibrium between quasi-bound and free water molecules on the surface of biomolecules (or self-assembly) predicts that the orientational relaxation at a macromolecular surface should indeed be biexponential, with a fast time component (few ps) nearly equal to that of the free water while the long time component is equal to the inverse of the rate of bound to free transition [4], In order to gain an in depth understanding of hydration dynamics, we have carried out detailed atomistic molecular dynamics (MD) simulation studies of water dynamics at the surface of an anionic micelle of cesium perfluorooctanoate (CsPFO), a cationic micelle of cetyl trimethy-lainmonium bromide (CTAB), and also at the surface of a small protein (enterotoxin) using classical, non-polarizable force fields. In particular we have studied the hydrogen bond lifetime dynamics, rotational and dielectric relaxation, translational diffusion and vibrational dynamics of the surface water molecules. In this article we discuss the water dynamics at the surface of CsPFO and of enterotoxin. 

Palmitic acid occurs naturally in all animal fats as the glyceride, palmitin, and in palm oil partly as the glyceride and partly uncombined. Palmitic acid is most conveniently obtained from olive oil after removal of oleic acid, or from Japanese beeswax. Synthetically, palmitic acid may he prepared hy heating cetyl alcohol with soda lime to 270°C or hy fusing oleic acid with potassium hydrate. 

Incorporation of metal ions into porphyrins is affected by other compounds in solution. Lowe and Phillips (25) found that copper(II) ions were chelated with dimethyl protoporphyrin ester 20,000 times faster in 2.5% sodium dodecylsulfate (SDS) than in 5% cetyl trimethyl ammonium bromide (CATB). The increased activity of SDS treated porphyrin was attributed to electrostatic attraction between anionic micelles formed around the tetrapyrrole nucleus and the metal cation. The authors also reported the influence of certain chelating agents on the rate of copper complex formation. Equimolar concentrations of copper and 8-hydroxyquinoline or sodium diethylthiocarbamate in 2.5% SDS increased the reaction rate 38 and 165 times, respectively, above the control. Secondary chelators may act by removing the hydration sphere on the metal ion increasing its attraction to pyrrole nitrogens (26). 

Margario add—C, H CO,OH—270—formerly supposed to exist as a glyceride in all fats, solid and.liquid. What had been taken formargaric acid was a mixture of 90 per cent of palmitic and 10 per cent of stearic acid. It is obtained by the action of potassium hydrate upon cetyl cyanide, as a white, crystalline body fusible at 59 .9 (1 F.). 

Cetyl alcohol Cetyl esters Chloral hydrate Chloroacetamide Chloroacetic acid Chlorobenzene Chloroform Chromium nitrate Chromium potassium sulfate Cl 77000 Cobalt acetate (ous) Coconut acid Coconut (Cocos nucifera) oil Cod liver oil Copal resin Corn (Zea mays) oil Corn (Zea mays) starch Cottonseed (Gossypium) oil Coumarone/indene resin C10-12 pareth-3 C10-12 pareth-6 C10-12 pareth-8 C12-14 pareth-1 C12-14 pareth-3 C12-14 pareth-4 C12-14 pareth-7 C12-14 pareth-8 C12-14 pareth-11 p-Cresol/dicyclopentadiene butylated reaction product Cumene hydroperoxide... 

Propyl alcohol Rapeseed (Brassica campestris) oil Rosin Silica Silica, hydrated Silicic acid Sodium cetyl sulfate Sodium cocoate Sodium dodecylbenzenesulfonate Sodium laurate... 

Little information is available on microemulsion-mediated synthesis of rhodium particles. Considering the importance of Rh nanoparticles in catalytic reactions, Kishida et al [426] developed a method using microemulsions. The reverse micelle was prepared with the surfactant NP-5 and cyclohexane as the continuous phase. An aqueous solution of rhodium chloride was solubilized in the micelle and hydrazine directly added to it at 25°C. The average particle size of rhodium thus obtained was about 3 nm. Kishida et al. [427] later extended the method to the use of a variety of non-ionic and ionic surfactants (C-15, i.e. polyoxyethylene(15)cetyl ether, L-23, i.e. polyoxyethylene(23)lauryl ether, NP-5 and NaAOT), as also cyclohexane or 1-hexanol (according to necessity) as the continuous phase. The reactants remained the same, i.e. rhodium chloride and hydrazine hydrate. In addition, the rhodium particles thus synthesized were coated with silica via hydrolysis-polycondensation of tetraethyl orthosilicate. The size of Rh varied in the range 1.5-4.0 nm in a typical case, a 4 nm particle was covered with a 14 nm thick layer of silica. 

---