Ethoxylates nonionic surfactants

Baby Shampoos. These shampoos, specifically marketed for small children, feature a non-eye stinging quaHty. The majority of the products in this category are based on an amphoteric detergent system a system combining the use of an imidazoline amphoteric with an ethoxylated nonionic surfactant has been successfiiUy marketed (15,16). The sulfosuccinates also have been suggested for baby shampoo preparation because of thek mildness... 

Solvents. The most widely used solvent is deionized water primarily because it is cheap and readily available. Other solvents include ethanol, propjdene glycol or butylene glycol, sorbitol, and ethoxylated nonionic surfactants. There is a trend in styling products toward alcohol-free formulas. This may have consumer appeal, but limits the formulator to using water-soluble polymers, and requires additional solvents to solubilize the fragrance and higher levels of preservatives. 

The phase inversion temperature (PIT) method is helpful when ethoxylated nonionic surfactants are used to obtain an oil-and-water emulsion. Heating the emulsion inverts it to a water-and-oil emulsion at a critical temperature. When the droplet size and interfacial tension reach a minimum, and upon cooling while stirring, it turns to a stable oil-and-water microemulsion form. " ... 

Ethoxylated fatty esters, emulsifiers, detergents, and dispersants, 8 710t Ethoxylated nonionic surfactants, microemulsions based on, 16 428 Ethoxylated surfactants, 24 142, 148 Ethoxylates, 24 149-151 Ethoxylation, fatty amines, 2 523 2-Ethoxypyridine, 21 104 Ethoxyquin, 10 854 13 42t, 51 2-Ethyl-1-butanol... 

Ethoxylated nonionic surfactants approximately obey a hnear mixing rule expressed as Eq. 1 when the characteristic property is the averaged number of ethylene oxide groups per molecules (EON) [35]. The goodness of the fit depends on the partitioning phenomena, which will be discussed later, in Sect. 4. 

As the temperature of dilute aqueous solutions containing ethoxylated nonionic surfactants is increased, the solutions may turn cloudy at a certain temperature, called the cloud point. At or above the cloud point, the cloudy solution may separate into two isotropic phases, one concentrated in surfactant (coacervate phase) and the other containing a low concentration of surfactant (dilute phase). As an example of the importance of this phenomena, detergency is sometimes optimum just below the cloud point, but a reduction in the washing effect can occur above the cloud point (95). However, the phase separation can improve acidizing operations in oil reservoirs (96) For surfactant mixtures, of particular interest is the effect of mixture composition on the cloud point and the distribution of components between the two phases above the cloud point. 

Cowell, M. A. Kibbey, T. C. G. Zimmerman, J. B. Hayes, K. F. Partitioning of Ethoxylated Nonionic Surfactants in Water/Non-Aqueous Phase Liquid (NAPL) Systems Effects of Surfactant and NAPL Properties, Environ. Sci. Technol, 2000,34, 1583-1588. 

Pennell, K. D. Adinolfi, A. M. Abriola, L. M. Diallo, M. S. "Solubilization of Dodecane, Tetrachloroethylene, and 1,2-Dichlorobenzene in Micellar Solutions of Ethoxylated Nonionic Surfactants." Environ. Sci. Technol. 1997,31, 1382-1389. 

A limited number of studies have considered the use of surfactant and cosolvent mixtures to enhance the recovery of NAPLs (Martel et al., 1993 Martel and Gelinas, 1996). Martel et al. (1993) and Martel and Gelinas (1996) employed ternary phase diagrams to select surfactant+cosolvent formulatons for treatment of NAPL-contaminated aquifers. The surfactant+cosolvent formulations used in their work, which included lauryl alcohol ethersulfate/n-amyl alcohol, secondary alkane sulfonate/n-butanol, and alkyl benzene sulfonate/n-butanol, were shown to be effective solubilizers of residual trichloroethene (TCE) and PCE in soil columns (Martel et al., 1993). However, very little information is available regarding the effect of cosolvents on the solubilization capacity and phase behavior of ethoxylated nonionic surfactants. 

The overall objective of this research was to evaluate the effects of cosolvent addition on the ability of an ethoxylated nonionic surfactant to recover PCE from a heterogeneous, 2-D system. The specific tasks of this work were to (a) quantify the PCE solubilization rate and capacity in the presence and absence of a representative cosolvent (EtOH) and (b) investigate the effects of EtOH addition on surfactant delivery, plume migration and PCE recovery in a 2-D, layered sand tank. A representative nonionic surfactant, polyoxyethylated (POE) (20) sorbitan monooleate (Tween 80), was selected for study because of its capacity to solubilize PCE ( 0.7 g PCE/g surf at 20°C) and relatively high interfacial tension with PCE (5 dynes/cm). EtOH was chosen as the representative cosolvent because of its relatively low density (p = 0.79 g/cm1) and regulatory acceptance. 

Pennell, K.D., Adinolfi, A.M., Abriola, L.M., and Diallo, M.S. (1997). Solubilization of dodecane, tetrachloroethylene, and 1,2-dichlorobenzene in micellar solutions of ethoxylated nonionic surfactants. Environ. Sci, Technol, 31, 1382-1389. 

They are now being replaced by the polyoxyethylene derivative of straight-chain primary or secondary alcohols with C10-C18. These linear alcohol ethoxylate nonionic surfactants are more biodegradable than nonylphenol derivatives and have better detergent properties than linear alkylbenzenesulfonate. 

Solutions (250 ppm) of Triton X-100, a commercial ethoxylated nonionic surfactant, were administered to excised barley leaves. Partial inhibition of photosynthetic oxygen evolution occurred In tissue segments taken from the leaves after 5 h of exposure, but there was a partial recovery of activity by the excised leaves during the next 18 h. In contrast, treatments with 2 ppm atra-zine caused nearly complete and irreversible inhibition ( ). 

M. Petrovic, D. Barcel6, Analysis of ethoxylated nonionic surfactants and their metabolites by LC-API-MS, J. Mass Spectrom., 36 (2001) 1173. 

Fabric softeners may also contain antistatic agents (anionic or ethoxylated nonionic surfactants) and/or humectants to increase the moisture level at the fabric surface [52],... 

Based on kinetic considerations, an equation (4.16) was proposed which represents the variation of the primary hydroxyl content as function of the quantity of EO reacted [52]. This equation is very similar to the equation of Weybull and Nicander [80, 81] used to measure the distribution of EO sequences per hydroxyl group in ethoxylated nonionic surfactants (for example, ethoxylated fatty alcohols). 

It is worth remarking that this is not the case for ethoxylated nonionic surfactants [75] or for some anionic ones such as disulfonates [76]. Sometimes surfactant mixing allows the cosurfactant requirements to be minimized [77]. 

This discussion indicates that pH-dependent systems are more complex to deal with than plain surfactant systems because of the eventual partitioning. This is also the case with many commercial surfactant mixtures, particularly those of ethoxylated nonionic surfactants, for which no simple and accurate rule can be used for formulation purposes [75,86]. 

Because of its basic phenomenon, the PIT is however limited to ethoxylated nonionic surfactant systems, and its experimentally attainable range (that tits the liquid water state at atmospheric pressure) is sometimes rather narrow, particularly in dealing with highly ethoxylated detergents and emuisilier,s. 

The experimental technique used to find an optimum formulation, known a.s untdimensional scan, goes on as follows. Series of surfactant-oil-water. systems are prepared in test tubes, all with identical composition, and with the same formulation with the exception of the scanned variable, that is in general the aqueous phase salinity for ionic systems, and the average number of ethylene oxide groups per molecule (EON) if the systems contain an ethoxylated nonionic surfactant mixture. 

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