Polyoxyethylene 23 dodecanol

Separation of colloids by GPC is an important technical advance that may help in the characterization of novel materials. One such separation was the shape separation of gold particles of nanometer size by GPC on a Nucleogel GFC 1000-8 column using sodium dodecyl sulfate and Brij-35 [polyoxyethylene (23) dodecanol] to modulate the adsorption properties of the colloidal gold.42 Rodlike and spherical particles were separated using UV-VIS detection. 

Polyoxyethylene(8)dodecanol Polyoxyethylene(23 )dodecanol Polyoxyethylene(9.5 )-t-octy 1-phenol Polyoxyethylene(7.5 )nonyl-phenyl ether Octylglucoside... 

HTAC cationic micelles also markedly enhance the CL intensity of fluorescein (FL) in the oxidation of hydrogen peroxide catalyzed by horseradish peroxidase (HRP) [39], However, no CL enhancement was observed when anionic micelles of sodium dodecyl sulphate (SDS) or nonionic micelles of polyoxyethylene (23) dodecanol (Brij-35) were used (Fig. 9). CL enhancement is attributed to the electrostatic interaction of the anionic fluorescein with the HTAC micelles. The local concentration of fluorescein on the surface of the micelle increases the efficiency of the energy transferred from the singlet oxygen (which is produced in the peroxidation catalyzed by the HRP) to fluorescein. This chemiluminescent enhancement was applied to the determination of traces of hydrogen peroxide. The detection limit was three times smaller than that obtained in aqueous solution. 

Aminophthalate anion Atmospheric pressure active nitrogen Analyte pulse perturbation-chemiluminescence spectroscopy Arthromyces rasomus peroxidase Ascorbic acid Adenosine triphosphate Avalanche photodiode 5-Bromo-4-chloro-3-indolyl 2,6-Di-t< r/-bu(yl-4-mclhyl phenol Bioluminescence Polyoxyethylene (23) dodecanol Bovine serum albumin Critical micelle concentration Calf alkaline phosphatase Continuous-addition-of-reagent Continuous-addition-of-reagent chemiluminescence spectroscopy Catecholamines Catechol... 

Nonionic Micelle-Forming Surfactants of General Formula RCOCH H OH R=C 2> n 23 Polyoxyethylene(23)dodecanol [Brij-35] 0.1 40... 

Conversely, the decrease in the rate constant for the hydroxide ion catalyzed reaction of l,l,l-trichloro-2-methyl-2-propanol in the presence of polyoxyethylene(23) dodecanol and polyoxyethylene sorbitan mono-decanoate has been rationalized by assuming that the nucleophilic reaction occurs only in the bulk solution and that a substantial fraction of the substrate is solubilized by the surfactant. The latter assumption was verified by measurements of the solubility of l,l,l-trichloro-2-methyl-2-propanol, and hence the distribution coefficients, in the micellar systems (Anderson and Slade, 1966). 

Micellar sodium dodecyl sulfate and polyoxyethylene(23) dodecanol, on the other hand, did not significantly affect the rate constants for nucleophilic aliphatic substitution reactions between neutral reactants (equations 39 and 40) in spite of the fact that anisylthioethane (see equation 40) is appreciably solubilized by the micelles while iodine cyanide is excluded (Herries et al., 1964). 

The autooxidation of linoleic acid has been investigated as a function of polyoxyethylene(23) dodecanol (Brij 35) and linoleic acid concentration (Swarbrick and Rhodes, 1965). At constant surfactant concentration, the rate of oxidation increased linearly with increasing linoleic acid... 

Quartz-distilled water was used throughout the work. Sodium acetate (Suprapur) and potassium peroxodisulfate (pro analysi) were products of Merck and were used as received. Polyoxyethylene(23)dodecanol (Brij-35) and polycyclic aromatic hydrocarbons were purchased from Aldrich and used without further puriflcation. A 0.010 M stock solution of 9,10-diphenyl-anthracene was prepared in ethanol and Wcis daily diluted to an appropriate concentration in the eluent. Nitrogen was of the purest grade available. 

Surprisingly, almost all the applied work in MLC to date appears to have involved only ionic micellar mobile phases composed of either anionic sodium dodecyl sulfate (SDS), or cationic hexadecyltrimethyl-ammonium bromide or chloride (CTAB or CTAC), and dodecyltrimethyl-ammonium bromide (DTAB). Reports on the use of unclmrg nonionic surfactants, such as Neodol 91-6 and polyoxyethylene(23) dodecanol (Brij 35) are exceptions. 

M.F. Borgerding and W.L. Hinze, Characterization and Evaluation of the Use of Nonionic Polyoxyethylene(23)dodecanol Micellar Mobile Phases in RPLC, Anal. Chem., 57 2183 (1985). 

Sintanol Kaprolaktam), and many other products. Ethoxylated secondary alcohols are known for example as "Gardinol C" Albright Wilson) and "Softanol" Nippon Shokubai). Individual polyoxyethylene ethers of dodecanol and other alcohols with w < 8 are supplied by Nikko Chemical Co. and Sigma-Aldrich. 

As a branch of the surfactant family tree, if the tried-and-true dodecanol is treated with ethylene oxide (OE) and base under rigid anhydrous conditions, the material obtained is an alkyl polyoxyethylene (POE) polyether. 

Surfactants are those chemicals whose molecules have two parts of widely differing polarity and solubility. The soaps, for example, have an ionizing salt head to the molecule and a long, non-polar hydrocarbon tail . A different type are the polyoxyethylene ethers of dodecyl alcohol (dodecanol), e.g. Ci2H25 0 (CH2 CH2 0)6 H. These contain the non-polar dodecyl group (C12H25-), from dodecyl alcohol, at one end of the molecule and the successive polar ether linkages at the other. 

Funasaki and coworkers [12] studied intermolecular interactions in mixed micelle formation of polyoxyethylene (15) dihydrocholesterol (DHC-E015) with polyoxyethylene (7) dodecanol (C12E07), by means of volumetric methods. The objective of their study was to investigate the condensing effect of cholesterol on phospholipid monolayers and the membrane-thickening action of cholesterol on lecithin bilayers. The volume... 

Riegelmann et al. [93] studied various aromatic compounds solubilized in aqueous solutions of potassium laurate, dodecylamine hydrochloride, and a polyoxyethylene ether of dodecanol (Brij 35). The ultraviolet spectra of ethylbenzene in these micellar solutions were very similar to those in non-polar solvents (see Fig. 5.10) and it was concluded that this solubilizate resided completely in the micellar core. Some regions of the spectra of solubilized naphthalene, anthracene and azobenzene, on the other hand, showed similarities with the spectra of these compounds in water, whilst other regions resembled the spectra in non-polar solvents. The suggestion was made that these compounds were solubilized in such a way as to be in partial contact with both the polar micellar surface and the non-polar micellar core, i.e. a position of deep penetration. By similar reasoning it was concluded that o-nitroaniline was located at a position of short penetration whereas dimethylphthalate, whose spectrum closely resembled the spectrum in water, was thought to be adsorbed on the micellar surface. 

Figure 8.4 Variation of cloud point of surfactant solutions as a function of calculated HLB value. values for linear primary dodecanol-polyoxyethylene condensates from Schott [32]. Brij 96 and Brij 98, the latter point being obtained by extrapolation to zero salt concentration of cloud points in a series of NaCl solutions. From Florence et al [31] with permission.

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