Phase glycol dodecyl ether

Freeze-fracture TEM combined with nuclear magnetic resonance and quasielastic light scattering was used to study the microstructure of surfactant-water systems and dynamics of o/w and bicontinuous ME systems [41], The authors reported a rather abrupt transition from a discontinuous droplet (o/w) to bicontinuous (oil-and-water) microstructure occurring at low surfactant concentration, close to a three-phase region in the constructed phase diagram of pentaethylene glycol dodecyl ether, water, and octane [41],... 

Figure 2. The phase diagram water/benzene/pentafethylene glycol) dodecyl ether at 30°C. Key IM, inverse micellar solution LLC, lamellar liquid crystal and unmarked, aqueous micellar solution.

According to Bancroft s rule the best type of emulsion raises the solubility of the emulsifier in its homogeneous phase. Hence, nonionic ethylene oxide adducts with a low degree of ethoxylation, for example the tetra glycol dodecyl ether, stabilise a water/oil type and higher ethoxylated products, such as EO 10, stabilise oil/water emulsions. Given a sufficient solubility... 

For the case when the lifetime is short with respect to A, the NMR experiment enables one to determine the longterm diffusion coefficient for the dispersed phase (or for molecules dissolved in the dispersed phase). An example of such a case is given by an emulsion composed of 96 wt % brine (of concentration 0.17M with respect to NaCl), 2.3 wt% heptane, 1.1 wt% tetraethylene glycol dodecyl ether (Cj2E4), and 0.3 wt % soybean phosphatidyl choline. The echo attenuation for three different values of A for this system is presented in Fig. 9. The data set in Fig. 9 is not compatible with diffusion within a closed droplet. Rather, the data is compatible with a Gaussian diffusion and one can obtain a common diffusion coefficient the value of which... 

In a recent work [417], the two-microemulsion method was used for synthesis. In microemulsion I, the continuous phase was prepared by mixing n-heptane with a surfactant or surfactant mixture from C12E4, C,2E5, i.e. penta(ethylene glycol)dodecyl ether, i.e. hexa(ethylene glycol)dodecyl ether or AOT. An... 

A number of other NMR-probed w/o microemulsions have appeared in recent literature. The diffusion coefficients in water/SDS/pentanol and ammonium hydro-xide/SDS/pentanol microemulsions investigated by Olsson et al. [35] estabhshed that replacement of water by ammonium hydroxide destabilizes the liquid crystalline phase and reduces the size of the colloidal association structure in the isotropic liquid region, Olsson and Schurtenberger [36] worked on nonionic microemulsions prepared from D2O, pentaethylene glycol dodecyl ether and decarie. Discrete oil-swollen micelles have been evidenced by NMR self-diffusion measurements the preparations are in conformity with the hard-sphere model. The NMR self-diffusion measurements on a water/octyl glucoside/pentanol/decane microemulsion system advocated a progressive decrease in the mean curvature of the surfactant film with water addition at a constant level of the oil [37]. It was concluded that the... 

ZHE Zheng, L., Suzuki, M., Inoue, T., and Lindman, B., Aqueous phase behavior of hexa(ethylene glycol) dodecyl ether studied by differential scanning calorimetry, Fourier transform infrared spectroscopy, and NMR spectroscopy, Langmuir, 18, 9204, 2002. 

Solubilization of a graft copolymer comprising a hydrophobic poly(dodecyl-methacrylate) backbone and hydrophilic poly(ethylene glycol) monomethyl ether side chains in water/AOT/cyclohexane w/o microemulsions was rationalized in terms of the backbone dissolved in the continuous apolar phase and the side chains entrapped within the aqueous micellar cores [189],... 

The first kinetics measurements about coalescence were reported by Kabalnov and Weers in water-in-oil emulsions [40]. These authors measured the characteristic time at which the layer of free water formed at the bottom of the emulsions corresponded approximately to half of the volume of the dispersed phase. This time was assumed to be equal to t. By measuring r at different temperatures, the activation energy was deduced from an Arrhenius plot. Kabalnov and Weers were able to obtain the activation energy for a water-in-octane emulsion at 50%, stabilized by the nonionic surfactant C12E5 (pentaethylene glycol mono n-dodecyl ether), above the phase inversion temperature (PIT), and found a value of 47 kgTr, Tr being the room temperature. 

Diethylene glycol monoalkyl ether was used as a cosurfactant in the formation of an oil-in-water styrene microemulsion. Sodium dodecyl sulphate was used as a surfactant. The pseudo three-component phase diagram, macroemulsion, microemulsion and lamellar gal phases, was constructed for the cosurfactants. A smaller number of latex particles nucleated than there were microemulsion droplets initially present. The diethylene glycol monoalkyl ether group of CiEj enhances the latex stability and the CiEj more effectively stabihses the styrene microemulsion and subsequent polymerisation compared with CiOH cosurfactants used as a comparison. 15 refs. 

The detection is based on a difference in mobility between bare K and a POE-K complex. The effects of K concentration in mobile phases and the complexation ability of POE on peak size are quantitatively evaluated. On the basis of theoretical considerations, the quantification scheme, where one monodisperse POE is used as a standard material for determination of all oligomers detected, is also presented. This scheme was applied to POE without chromophores, such as polyethylene glycols (PEG) and polyoxyethylene dodecyl ethers. 

Although non-ionic surfactants would appear to be unlikely candidates as complexing agents for metal ions, the interaction of some polyoxyethylene glycols with metal ions has recently attracted interest [90,91]. The reaction of non-cyclic polyoxyethylene derivatives with alkali and alkaline earth metals has been studied by means of solvent extraction of their thiocyanates or iodides. Polyoxyethylene dodecyl ethers with more than 7 ethylene oxide units were able to bind potassium ion in the water phase and to transfer the complexed salt to the organic phase the extracting power of Ci2Eg was about one sixth of that of a crown ether [92]. Some results are shown in Fig. 11.13. 

The structure of the lamellar phase of aqueous pentaethylene glycol mono- -dodecyl ether (C12E5) surfactant at various temperatures and... 

There has been a useful review of phase-transfer catalysis in nucleophilic aromatic substimtion. A comparison has been reported of the reactions with nucleophiles of l-chloro-2,4-dinitrobenzene (substimtion) and 4-nitrophenyl diphenyl phosphate (dephosphorylation) in neutral micelles of dodecyl (10) and (23) polyoxyethylene glycol. In the substimtion reaction considerable amounts of ether may be formed by reaction with alkoxide ions at the micellar surface. Differences in reactivity of the two substrates are probably due to differences in their location in the micellar structures. ... 

Large quantities of hydrocarbon oils may be solubilized by aqueous lamellar dispersion of nonionic surfactants of the type n-dodecyl polyethylene glycol ether (1) in the case of the lamellar phase of n-dodecyl tetraethylene glycol ether UP to 55% (W/W) of n-... 

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