Nonionic surfactant examples

Amine oxides constitute another important class of nonionic surfactants. Examples of these surfactants include dimethyl dodecyl amine oxide (DMDAO) and cocoamidopropyl dimethyl amine oxide (CAPAO). This type of surfactant is nonionic at pHs above its pK and cationic below that point. When functioning as a nonionic, amine oxides have many useful properties. They interact strongly with anionics, which can result in performance benefits. Amine oxides help to mitigate anionic surfactant irritation, act as foam stabilizers, and can also function to improve grease removal. 

Nonionic detergents, as the name implies, are not electrolytes, although they do possess the general polar-nonpolar character typical of surfactants. Examples of common types would include polyether esters, for... 

Three generations of latices as characterized by the type of surfactant used in manufacture have been defined (53). The first generation includes latices made with conventional (/) anionic surfactants like fatty acid soaps, alkyl carboxylates, alkyl sulfates, and alkyl sulfonates (54) (2) nonionic surfactants like poly(ethylene oxide) or poly(vinyl alcohol) used to improve freeze—thaw and shear stabiUty and (J) cationic surfactants like amines, nitriles, and other nitrogen bases, rarely used because of incompatibiUty problems. Portiand cement latex modifiers are one example where cationic surfactants are used. Anionic surfactants yield smaller particles than nonionic surfactants (55). Often a combination of anionic surfactants or anionic and nonionic surfactants are used to provide improved stabiUty. The stabilizing abiUty of anionic fatty acid soaps diminishes at lower pH as the soaps revert to their acids. First-generation latices also suffer from the presence of soap on the polymer particles at the end of the polymerization. Steam and vacuum stripping methods are often used to remove the soap and unreacted monomer from the final product (56). 

Etherification. Many of the mono alkylphenols and some of the dialkylphenols are converted into ethoxylates which find commercial apphcation as nonionic surfactants (9). For example, -nonylphenol reacts with ethylene oxide under mild basic conditions. 

Examples of nonionic surfactants are Emulphor ON and the Igepals (both Antara Chemicals), and Triton X-100 (Rohm Haas Company). 

Nonionic surfactants perform well in nonpolar polymers such as polyethylene and polypropylene. Examples of nonionic surfactants ate ethoxylated fatty amines, fatty diethanolamides, and mono- and diglycetides (see Amines, fatty amines Alkanolamines). Amphoteric surfactants find Httle use in plastics (134). 

A series of sorbitol-based nonionic surfactants are used ia foods as water-ia-oil emulsifiers and defoamers. They are produced by reaction of fatty acids with sorbitol. During reaction, cycHc dehydration as well as esterification (primary hydroxyl group) occurs so that the hydrophilic portion is not only sorbitol but also its mono- and dianhydride. The product known as sorbitan monostearate [1338-41 -6] for example, is a mixture of partial stearic and palmitic acid esters (sorbitan monopalmitate [26266-57-9]) of sorbitol, 1,5-anhydro-D-glucitol [154-58-8] 1,4-sorbitan [27299-12-3] and isosorbide [652-67-5]. Sorbitan esters, such as the foregoing and also sorbitan monolaurate [1338-39-2] and sorbitan monooleate [1338-43-8], can be further modified by reaction with ethylene oxide to produce ethoxylated sorbitan esters, also nonionic detergents FDA approved for food use. 

In most cases, these active defoaming components are insoluble in the defoamer formulation as weU as in the foaming media, but there are cases which function by the inverted cloud-point mechanism (3). These products are soluble at low temperature and precipitate when the temperature is raised. When precipitated, these defoamer—surfactants function as defoamers when dissolved, they may act as foam stabilizers. Examples of this type are the block polymers of poly(ethylene oxide) and poly(propylene oxide) and other low HLB (hydrophilic—lipophilic balance) nonionic surfactants. 

Since poly(oxyethylene)-type nonionic surfactants have a capability of facilitating the transfer of cations [51,52], the above interphase complexation may be seen as an example of precomplex formation before the bulk transfer of ions, which is seen when Aq (p is sufficiently positive. The presence of such precomplex formation at the interface, which is detectable voltammetrically [53], may have significance in the rate of complex formation and the selectivity in the bulk facilitated transfer. 

Such a desorbent may be, for example, a hydrophilic nonionic surfactant, which is among the least expensive on the market and is suitable in calcic environment... 

We will show several examples of the use of 2DLC for nonionic surfactants. The resulting resolution can be dramatically different depending on the two separation modes in the 2DLC system. As discussed previously, the separation of the hydrophobic groups can be accomplished with a reversed-phase column, and the separation of the... 

The primary application of these alcohols is the manufacture of anionic or nonionic surfactants for personal cleansing products, most of which end up in your wastewater treatment plants and rivers. Microorganisms don t chew up branch-chain surfactants as well as they do the straight ones. It used to be, for example that the surfactant based on the sodium salt of dodecyl benzene sulfonate, a 12-carbon branch chained anionic surfactant, was found to be slowing, down water treatment processes. Dodecyl alcohol as a raw material for these surfactants has been largely replaced by laurel alcohol, a 12-carbon straight-chain, linear alcohol. If you look at the bottle next time you shampoo your hair and rinse, you ll see sulfonates based on laurel alcohol listed, but none based on dodecyl. 

The difficulty with HLB as an index of physicochemical properties is that it is not a unique value, as the data of Zaslavsky et al. (1) on the haemolytic activity of three alkyl mercaptan polyoxyethylene derivatives clearly show in Table 1. Nevertheless data on promotion of the absorption of drugs by series of nonionic surfactants, when plotted as a function of HLB do show patterns of behaviour which can assist in pin-pointing the necessary lipophilicity required for optimal biological activity. It is evident however, that structural specificity plays a part in interactions of nonionic surfactants with biomembranes as shown in Table 1. It is reasonable to assume that membranes with different lipophilicities will"require" surfactants of different HLB to achieve penetration and fluidization one of the difficulties in discerning this optimal value of HLB resides in the problems of analysis of data in the literature. For example, Hirai et al. (8 ) examined the effect of a large series of alkyl polyoxyethylene ethers (C4,C0, Cj2 and C 2 series) on the absorption of insulin through the nasal mucosa of rats. Some results are shown in Table II. 

Surfactants are major compounds that reach the subsurface alone or accompanying other contaminants. Their effect depends highly on the solution chemishy. For example. Park and Bielefeldt (2003) report the partitioning of Tergitol a nonionic surfactant, and pentachlorophenol (PCP), from nonaqueous phase hquid (NAPL) to an aqueous solution. Enhanced PCP dissolution into water from the NAPL was... 

Provided that the temperature remains below Tc, where the micellar solution Li separates into and L" phases (see Fig. 1), the rate of dissolution of pure nonionic surfactants increases with increasing temperature. For example, dissolution time fo for a drop of Ci2(FO)6 with Ro = 73 pm was 11 s at 35 °C. As indicated above, to is proportional to Rq, so that to would be about 13 s at this temperature if Ro were 78 pm. As indicated in the preceding paragraph, a drop with Ro = 78 pm dissolved more slowly, taking 16 s, when the temperature was reduced to 30 °C. 

The description of a mixed adsorption layer of ionic and nonionic surfactants requires the appropriate adsorption isotherms. For example, the Frumkin isotherm gives... 

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