Polyoxyethylene aryl ethers

Surfactants Nonionic Sorbitan esters Polysorbates Polyoxyethylene alkyl ethers Polyoxyethylene alkyl esters Polyoxyethylene aryl ethers Glycerol esters Cholesterol Anionic Sodium dodecyl sulphate Cationic Cetrimide Benzalkonium chloride... 

Interactions of Nonionic Polyoxyethylene Alkyl and Aryl Ethers with Membranes and Other Biological Systems... 

It has been recognised for some time (see for example reference 1), that surfactants can increase the rate and extent of transport of solute molecules through biological membranes by fluidisation of the membrane. It is only recently, however, that sufficient work has been carried out to allow some analysis of structure-action relationships. In this overview an attempt is made, by reference to our own work and to work in the literature, to define those structural features in polyoxyethylene alkyl and aryl ethers which give rise to biological activity, especially as it is manifested in interactions with biomembranes and subsequent increase in the transport of drug molecules. 

Furthermore, aggregates of nonionic surfactants like polyoxyethylene alkyl/aryl ethers of the Tergitol, Triton, and Brij series were used as templates for the formation of mesoporous silica materials in neutral or acidic media. The pore diameters of the materials that can be obtained with these surfactants are restricted to around 5.5 nm. The advantages of these surfactants over triblock copolymers are that they are cheap, nontoxic, and biodegradable. An overview of the most commonly used SDAs is compiled in Table 3.1. 

Alkyl sulfates Quaternary ammonium compounds Polyoxyethylene alkyl-aryl ethers... 

Commercial admixtures employed were a polyalkyl aryl sulfonate-type high range water-reducing agent, four polyoxyethylene nonylphenol ether-type... 

Epoxy-modified mortars which are prepared by mixing most popular bisphenol A-type epoxy resin with commercial modified polyamide-amine hardener, polyalkyl aryl sulfonate-type water-reducing agent, polyoxyethylene nonylphenol ether-type nonionic surfactant and silicone emulsion-type antifoamer into cement mortar have excellent properties comparable to ordinary polymer-modified mortars using latex-type cement modifiers[5]. The optimum mix proportions of the epoxy-modified mortars are shown in Table 2. Their disadvantage is a need of much higher polymer-cement ratio than the ordinary polymer-modified mortars. Therefore, the development of low-cost, effective dispersants is expected in the near future. 

Aughel and coworkers [63] studied the phase behavior of hydrocarbon-water mixtures in the presence of alkyl(aryl)polyoxyethylene carboxylates for enhanced oil recovery and found good salt tolerance with an alkyl ether carboxy-late (C13-C15) with 7 mol EO and a good microemulsion forming effect with the 3 EO type. 

This paper is largely confined to the alkyl and aryl polyoxyethylene ethers, as these form series variable in both hydrophobic and hydrophilic chain length, and hence HLB, with minimal structural variation. 

Studies with homologous series of alkyl and aryl polyoxyethylene ethers... 

In contrast to the R-preference displayed by CALB, quite impressive S-preference toward several 1-aryl-l-ethanols can be achieved by using a protease, the commercially available subtilisin Carlsberg, as catalyst, and isopropenyl pen-tanoate as the acyl donor in THF in the presence of sodium carbonate [74]. To achieve a successful resolution, the protease has to be treated with a mixture of two surfactants, octyl-P-D-glycopyranoside and Brij 56 [the monocetyl ether of polyoxyethylene (10)], 4/1/1 by weight, at pH 7.2, and then lyophilized before use. 

A plot of the temperatures required for clouding versus surfactant concentration typically exhibits a minimum in the case of nonionic surfactants (or a maximum in the case of zwitterionics) in its coexistence curve, with the temperature and surfactant concentration at which the minimum (or maximum) occurs being referred to as the critical temperature and concentration, respectively. This type of behavior is also exhibited by other nonionic surfactants, that is, nonionic polymers, // - a I k y I s u I Any lalcoh o I s, hydroxymethyl or ethyl celluloses, dimethylalkylphosphine oxides, or, most commonly, alkyl (or aryl) polyoxyethylene ethers. Likewise, certain zwitterionic surfactant solutions can also exhibit critical behavior in which an upper rather than a lower consolute boundary is present. Previously, metal ions (in the form of metal chelate complexes) were extracted and enriched from aqueous media using such a cloud point extraction approach with nonionic surfactants. Extraction efficiencies in excess of 98% for such metal ion extraction techniques were achieved with enrichment factors in the range of 45-200. In addition to metal ion enrichments, this type of micellar cloud point extraction approach has been reported to be useful for the separation of hydrophobic from hydrophilic proteins, both originally present in an aqueous solution, and also for the preconcentration of the former type of proteins. 

Chem. Descrip. Alkyl aryl polyoxyethylene ether, free fatty acids, and isopropanol Ionic Nature Nonionic... 

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