Polyethylene oxide surfactants

In the presence of polyethylene oxide MW 300,000 at a concentration of 0.025 g liter , variations in pH and ionic strength have no effect on elution volumes and a single calibration curve is obtained as shown in Figure 4 and Table II. This behavior presumably also results from modification of the glass surface by the polyethylene oxide surfactant, but in this case charge effects appear to be completely suppressed and the effective pore diameter and volume reduced. Such an interpretation is also in accord with the fact that the elution voliomes are lower with polyethylene oxide than with Tergitol, since Tergitol is a much smaller molecule than the polyethylene oxide. 

Zonyl A, a nonionic polyethylene oxide surfactant. Benzylchloride. 

Solid hydrocarbon soils can be rapidly removed from the surface of a ZnSe IRE by alkyl polyethylene oxide) surfactants. The removal mechanism involves penetration of a small amount of the surfactant into the hydrocarbon layer, which causes an increase in methylene chain defects in the soil, and displacement of solid soil from the substrate. Solubilization of a large fraction of the solid soil is not required. 

Bagshaw, S. A., Prouzet, E. and Pinnavaia, T. J. Templating of mesoporous molecular sieves by nonionic polyethylene oxide surfactants, Science, 1995, 269, 1242-1244. 

Catalysts and catalytic supports are often formulated from aluminas owing to their low cost, and their thermal, chemical and mechanical stability [27], To this end, nonionic surfactant templating with polyethylene oxide surfactants was used to synthesize mesoporous alumina [28], Partially ordered mesoporous materials with wormhole channels were obtained - this seems to be a characteristic of templating with nonionic surfactants. Cationic surfactants have recently been found to template mesoporous aluminum oxide with pore sizes that could be fine-tuned by varying the molar ratio of the reactants [29]. The material obtained was thermally stable to 900 °C and exhibited a narrow pore size distribution. 

There have been only a few reports of mesostructured metal sulfides. Mesoporous cadmium sulfide was prepared from polyethylene oxide surfactants and cadmium salts exposed to hydrogen sulfide [35], A study of the effects of the counter-anion on the formation of CdS mesostructures led to the conclusion that the use of cadmium nitrate and perchlorate salts improved the degree of order of the mesostructure over the chloride, sulfate and acetate salts. This effect was attributed to the stronger acidity of conjugate acid by-products of the reaction in the case of nitrates that leads to the dissolution of high-energy defects and enhances structural order. 

SBA-x Santa Barbara no. x, a series of mesoporous materials Tergitol alkyl-polyethylene oxide surfactant, C H2 +i (EO) ... 

Two other mesoporous silicates, HMS and MSU-n, were prepared at room temperature in the presence of neutral amines, and polyethylene oxide surfactants, respectively. They have parallel cylindrical channels, but are not identical to MCM-41 [69,70,72]. The main structural difference is that the pore system of HMS and MSU-n silicates is much less ordered than that of MCM-41. 

Highly polar microdomains exist in reverse micelles of AOT and nonionic polyethylene oxide surfactants in ethane, even below 100 bar, both with and without cosolvents. Without cosolvents these domains are likely very small since values of Wo are small. The addition of the cosolvent octane provides a means to take up large amounts of water over a wide pressure range. The polarities in the interior of the micelles approach that of bulk water. The existence of polar microdomains in supercritical fluids at relatively low pressures presents an opportunity for new separation and reaction processes involving hydrophilic substances. 

Lamellar (no channel) Channel hexagonal p6mm (1 7) MCM-50 MCM-41 SBA-3 SBA-15 polyethylene oxide) surfactant, CTA long-chain alkyl trimethylammonium (CTA), long-chain alkyl trimethylammonium... 

The relative viscosity of the polyethylene oxide-surfactant solution, Tirel =n(PEO + surfactant)/(PEO), is plotted in Figure 2 as a function of the surfactant concentration for different surfactants. For anionic SDS, Heel remains invariant at 1 up to a concentration of 4 x 10 M, indicating absence of any association. Beyond 4 x 10 M SDS, the relative viscosity shows a large increase up to about 2.6 x 10 M SDS. This can be attributed to the association of SDS micelles with the PEO segments and the resulting expansion of the PEO molecules. Beyond 2.6 X 10 M SDS, a reduction in the relative viscosity is observed. This is because, when saturation binding of SDS to PEO is reached (say at 2.6... 

Figure 2. Influence of various types of surfactants on the relative viscosity of the solutions containing 1000 ppm polyethylene oxide-surfactant micelle complexes.

Figure 5.6 Aggregation number of non-ionic polyethylene oxide surfactants. Points are experimental data at 25 °C and the lines are regression results. The abbreviations are as shown in Table 5.1. From Cheng (2003, Phd Thesis), Technical University of Denmark...

Kautzner, B., R. H. Laby, Colorimetric determination of nonionic polyethylene oxide surfactants, GIT Fachz. Lab., 1988, 32, 527,529-532. 

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