Oxide alkyl ether, ethylene

Based on Oligo(ethylene oxide)-Alkyl Ether Surfactants. 210... 

In addition to catalysis of small molecule transformations and biocatalysis, non-functionalized LLC phases used as reaction media have also been found to accelerate polymerization reactions as well. For example, the L and Hi phases of the sodium dodecylsulfate/n-pentanol/sulfuric acid system have been found to lower the electric potential needed to electropolymerize aniline to form the conducting polymer, polyaniline [110]. In this system, it was also found that the catalytic efficiency of the L phase was superior to that of the Hi phase. In addition to this work, the Ii, Hi, Qi, and L phases of non-charged Brij surfactants (i.e., oligo(ethylene oxide)-alkyl ether surfactants) have been observed to accelerate the rate of photo-initiated radical polymerization of acrylate monomers dissolved in the hydrophobic domains [111, 112]. The extent of polymerization rate acceleration was found to depend on the geometry of the LLC phase in these systems. Collectively, this body of work on catalysis with non-functionalized LLC phases indicates that LLC phase geometry and system composition have a large influence on reaction rate. 

Only a few surfactant systems and their derivatives have been explored as LLC-based drug delivery systems because of the chemical and physiological compatibility requirements listed above, and because of cost and availability issues. These LLCs include commercially available non-ionic surfactants such as esters of oleic acid and related fatty acids [e.g., glyceryl monooleate (GMO) (aka, monoolein)], and oligo(ethylene oxide)-alkyl ether surfactants (e.g.,... 

Glyceryl monooleate (GMO) (aka, monoolein) Oligo(ethylene oxide)-alkyl ether surfactants... 

Drug delivery from LLC phases of oligo(ethylene oxide)-alkyl ether (i.e., (E0) -0-alkyl) surfactants have also been explored but to a much lesser extent than GMO. For example, the L, Qn, and Hu phases of commercial Brij-96 surfactant (i.e., (EO)io-O-oleyl) (Fig. 18) formed with water and other additives, have been explored for release of ephedrine hydrochloride, tenoxi-cam [145], and topical dermal delivery of benzocaine [146]. Work in this area has found that the amount of water swelling the hydrophilic domains of the LLC phase increases drug diffusion and release [145]. In addition to this work, the L phase of the (EO)2i-0-stearyl/oil/water system has been explored for dermal delivery of itraconazole [147] and the L and Hi phases of the (E0)7-0-Ci3 i5 (i.e., Symperonic A7)/water system have been explored for the release of the model drug chlorhexidine diacetate [148]. 

The most widely studied group of nonionic surfactants is that of the poly(ethylene oxide) alkyl ethers [ -C H2 +i(OCH2CH2)j OH C EO ] [37,101]. One reason forthis is that it is possible to study the phase behavior... 

The phase behavior of related polymers and monomers containing the rigid biphenyl moiety are studied in a later paper [131]. The phase behavior of the monomeric surfactants is generally compatible with that of common nonionic surfactants (especially ethylene oxide alkyl ethers). They exhibit Ii (sometimes two), Hj and L phases as well as clouding. The polymers, which have an average degree of polymerization of 55, nearly all exhibit H, and L phases, whereas the Ij phase is only seen in one (PC3BiE i)55. One major difference between the polymer and monomer phase behavior is the appearance of a nematic phase (Nc) built up of rod-like micelles in a num-... 

This brief survey begins in Sec. II with studies of the aggregation behavior of the anionic surfactant AOT (sodium bis-2-ethylhexyI sulfosuccinate) and of nonionic pol-y(ethylene oxide) alkyl ethers in supercritical fluid ethane and compressed liquid propane. One- and two-phase reverse micelle systems are formed in which the volume of the oil component greatly exceeds the volume of water. In Sec. Ill we continue with investigations into three-component systems of AOT, compressed liquid propane, and water. These microemulsion systems are of the classical Winsor type that contain water and oil in relatively equal amounts. We next examine the effect of the alkane carbon number of the oil on surfactant phase behavior in Sec. IV. Unusual reversals of phase behavior occur in alkanes lighter than hexane in both reverse micelle and Winsor systems. Unusual phase behavior, together with pressure-driven phase transitions, can be explained and modeled by a modest extension of existing theories of surfactant phase behavior. Finally, Sec. V describes efforts to create surfactants suitable for use in supercritical CO2, and applications of surfactants in supercritical fluids are covered in Sec. VI. 

Although poly(ethylene oxide) alkyl ethers are readily soluble in ethane and propane, especially those having less than five ethylene oxide units in their headgroups, their solubility is reduced considerably when water is added to the system [31]. For the polydisperse surfactant Cn-uEOs, the is 5 at 35°C and 200 bar [11], which is comparable to an AOT system at the same pressure and temperature [20]. At such low Wq values it is likely that water hydrates the ethylene oxide units rather than forming water pools. In propane, higher values are possible, just as in the case of AOT. In P- T space the... 

This chapter reviews and presents the latest developments on the work on the nonionic microemulsions stabilized by surfactants of ethylene oxide alkyl ether type, C ,En, where m is the number of carbons in the alkyl chain and n is the number of ethylene oxide groups. 

Most often, commercially available and purely organic amphiphilic, self-assembling molecules are applied in the synthesis of mesostructured materials such as ionic surfactants or block copolymers, i.e. Pluronic surfactants (PEO-f>-PPO-f>-PEO with PPO = poly(propylene oxide)) or poly(ethylene oxide) alkyl ether surfactants (Brij ). However, due to the restricted availability of amphiphilic block copolymers, not only are the accessible pore sizes and phases limited, but commercial products are sometimes inhomogeneous and have high molecular weight distributions [2]. 

Nilsson, P.-G., Wennerstrom, H., and Lindman, B. 1983 Stmctuie of micellar soln-tions of nonionic surfactants. Nuclear magnetic resonance self-diffusion and proton relaxation studies of poly (ethylene oxide) alkyl ethers, J. Phys. Chem. 87 1377-1385. 

L0 Olofssorr, G., Micelle formation in non-aqueotrs solverrts calorimetric study of the association of poly(ethylene oxide) alkyl ethers arrd hexadecyltrimethylarrrmorrirrm brorrride in formarrride, J. Chem. Soc., Faraday Trans., 87, 3037,1991. 

In contrast to alkylations with most of the alkyl halides, the reactions of anions with ethylene oxide in organic solvents such as diethyl ether and THE... 

The reaction of lithiated cumulenic ethers with ethylene oxide, trimethyl-chlorosilane and carbonyl compounds shows the same regiosnecificity as does the alkylation. 

Allyl Glycidyl Ether. This ether is used mainly as a raw material for silane coupling agents and epichlorohydrin mbber. Epichlorohydrin mbber is synthesized by polymerizing the epoxy group of epichlorohydrin, ethylene oxide, propylene oxide, and aHyl glycidyl ether, AGE, with an aluminum alkyl catalyst (36). This mbber has high cold-resistance. 

Linear ethoxylates are the preferred raw materials for production of ether sulfates used in detergent formulations because of uniformity, high purity, and biodegradabihty. The alkyl chain is usually in the to range having a molar ethylene oxide alcohol ratio of anywhere from 1 1 to 7 1. 

Variations and Improvements on Alkylations of Chiral OxazoUnes Metalated chiral oxazolines can be trapped with a variety of different electrophiles including alkyl halides, aldehydes,and epoxides to afford useful products. For example, treatment of oxazoline 20 with -BuLi followed by addition of ethylene oxide and chlorotrimethylsilane yields silyl ether 21. A second metalation/alkylation followed by acidic hydrolysis provides chiral lactone 22 in 54% yield and 86% ee. A similar... 

The addition of ethylene oxide to the alcohol causes a decrease in the melting point of the corresponding salt of the alcohol ether sulfate in comparison with the same alcohol sulfate. Weil et al. [65] prepared pure hexadecyl and octadecyl ether alcohols from the corresponding alkyl bromide and glycols with... 

Sodium dodecylbenzenesulfonate is undoubtedly the anionic surfactant used in the greatest amount because it is the basic component in almost all laundry and dishwashing detergents in powder and liquid forms. However, alcohol and alcohol ether sulfates are the more versatile anionic surfactants because their properties vary, with the alkyl chain, with the number of moles of ethylene oxide added to the base alcohol and with the cation. Consequently, alcohol and alcohol ether sulfates are used in almost all scientific, consumer, and industrial applications. 

It is difficult to find an industrial sector that does not use alcohol sulfates or alcohol ether sulfates. These surfactants are rendered so versatile in their chemical structure through varying their alkyl chain distribution, the number of moles of ethylene oxide, or the cation that it is possible to find the adequate sulfate achieving the highest mark in nearly every surfactant property. This and the relative low cost are the two main reasons for their vast industrial use. 

Alcohols react with nascent hydroiodic acid to form alkyl iodides. When the starting material is an alcohol ether sulfate, the resulting alcohol ethoxylate obtained by acid hydrolysis of the sulfate gives the corresponding alkyl iodides. The number of moles of diiodoethane equals the number of moles of ethylene oxide present in the alcohol ethoxylate. Diiodoethane decomposes or reacts with more hydrogen iodide to give iodine quantitatively in both cases. However,... 

Generally ether carboxylates are not suitable for a syndet soap because they are waxy due to the ethylene oxide distribution. The solid ether carboxylates with a long alkyl chain and a low degree of ethoxylation have a bad foam. By use of nonethoxylated ether carboxylates, e.g., a carboxymethylated fatty acid monoethanolamide with the structure... 

More traditional carbon nucleophiles can also be used for an alkylative ring-opening strategy, as exemplified by the titanium tetrachloride promoted reaction of trimethylsilyl enol ethers (82) with ethylene oxide, a protocol which provides aldol products (84) in moderate to good yields <00TL763>. While typical lithium enolates of esters and ketones do not react directly with epoxides, aluminum ester enolates (e.g., 86) can be used quite effectively. This methodology is the subject of a recent review <00T1149>. 

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