Anionic surfactants sulfosuccinates

In the manufacture of coating materials, paints, varnishes, lacquers, dyestuff pigments, binding materials, and binders, surfactants are of great importance. Most of the systems used in these fields are dispersed. Therefore surfactants can accelerate the preparations of dispersions and improve their stability. For rewetting processes, like the so-called flush process, besides other anionic surfactants sulfosuccinates are also used. 

Results can sometimes be unexpected. The first study of this type made use of labeled Aerosol OTN [111], an anionic surfactant, also known as di-n-octylsodium sulfosuccinate. The measured F was twice that in Eq. III-93 and it was realized that hydrolysis had occurred, that is, X + H2O = HX + OH , and that it was the undissociated acid HX that was surface-active. Since pH was essentially constant, the activity of HX was just proportional to C. A similar behavior was found for aqueous sodium stearate [112]. 

A.lkyl Sulfosuccinate Half Asters. These detergents are prepared by reaction of maleic anhydride and a primary fatty alcohol, followed by sulfonation with sodium bisulfite. A typical member of this group is disodium lauryl sulfosucciaate [26838-05-1]. Although not known as effective foamers, these surfactants can boost foams and act as stabilizers when used ia combination with other anionic surfactants. In combination with alkyl sulfates, they are said to reduce the irritation effects of the latter (6). 

These anionic surfactants are based on the petrochemically gained maleic acid anhydride. Sulfosuccinates are surface-active metal (mostly sodium) salts of either monoester or diesters of sulfosuccinic acid. 

Analytical methods for qualitative and quantitative determination of all kinds of surfactants have long been established. There can be found either wet chemical methods—like titration—or methods of instrumental analytics. A classical method for anionic surfactants is the so-called two-phase-titration [63]. Using this method nearly every molecule bearing an anionic group is detected. The correct determination of sulfosuccinates is limited to the interferences of the other ingredients and byproducts present. With few exceptions all sulfosuccinates react with special indicators, e.g., hyamin 1622 (Rohm and Haas), to form an anionic-cationic complex and hence are to be analyzed by active content titration. 

The storage behavior of sulfosuccinates is generally enormously improved by the addition of anionic surfactants. It is well known that addition of only 10% of NLES, for example, doubles the possible storage time of a sensitive ... 

Sulfosuccinates are not only less irritating to skin and mucus membranes than other surfactants, but it was also found that they reduce skin irritation of other surfactants used in skin and hair care products. In particular, the effect on sodium lauryl ether sulfate was found to be most pronounced [103]. Figure 14 shows the mollifying effect of disodium oleic acid monoethanol amide sulfo-succinate when blended with anionic surfactant at a total concentration of 15%. 

Choose alkylnaphthalene sulfonates and sulfosuccinate esters as hydrotropes in formulations where foaming needs to be controlled, as they enhance solubility of anionic surfactants without increasing foam amount [20],... 

A wide range of anionic surfactants (Fig. 23) has been classified into groups, including alkyl benzene sulfonates (ABS), linear alkyl benzene sulfonates (LAS), alcohol sulfates (AS), alcohol ether sulfates (AES), alkyl phenol ether sulfates (APES), fatty acid amide ether sulfates (FAES), alpha-olefin sulfates (AOS), paraffin sulfonates, alpha sulfonated fatty acids and esters, sulfonated fatty acids and esters, mono- and di-ester sulfosuccinates, sulfosuccinamates, petroleum sulfonates, phosphate esters, and ligno-sulfonates. Of the anionic surfactants, ABS and LAS continue to be the major products of anionic surfactants [314, 324]. Anionic surfactants have been extensively monitored and characterized in various environmental matrices [34,35,45,325-329]. 

In the case of ionic surfactants, a reduction in aggregation number will result when the counter-ion radius is increased (Kon-no and Kitahara, 1971a). The change in the size of aggregates as a function of the structure of ionic surfactants was studied (Eicke, 1980 Kon-no and Kitahara, 1971a Kon-no et al., 1983 Matijevic, 1993 Ward and C. du Reau, 1993). The aggregation numbers of anionic surfactants (sodium bis(2-ethylhexyl)sulfosuccinate and sodium l,3-(2-... 

About 4 percent of 2-ethylhexanol domestic demand is consumed in the manufacture of di-2-ethylhexyl sulfosuccinate -a general purpose anionic surfactant used in textile processing. 

Several other anionic surfactants are commercially available, such as sulfosuccinates, isethionates, and taurates, and these are sometimes used for special applications. The carboxylates and sulfates are sometimes modified by the incorporation of a few moles of ethylene oxide (referred to as ether carboxylates and ether sulfates, respectively). 

The expected trends are born out for the low molecular weight enzymes ribonuclease-a, cytochrome-c, and lysozyme, as shown in Figure 2. These results are presented as the percentage of the protein transferred from a 1 mg/ml aqueous protein solution to an equal volume of isooctane containing 50 mM of the anionic surfactant Aerosol 0T, or AOT (di-2-ethylhexyl sodium sulfosuccinate). As anticipated, only at pH s lower than the pi was there any appreciable solubilisation of a given protein, while above the pi the solubilisation appears to have been totally suppressed. Note, however, that as the pH was lowered even further, there was a drop in the degree of solubilisation of the proteins. This was accompanied by the formation of a precipitate at the interface between the two phases, attributed to a denaturation of the protein. 

Aqueous pH alters the protein charge property and affects the extraction efficiency. Haemoglobin (Mw 64,500, pi 6.8) is a difficult protein in terms of being able to completely extract it into reverse micelles. The representative anionic surfactant, di-2-ethylhexyl sulfosuccinate (AOT), cannot extract it, and gives rise to an interfacial precipitate. In contrast, we succeeded in the complete extraction of haemoglobin using synthetic anionic surfactants, dioleyl phosphoric acid (DOLPA), as seen in... 

Figure 14.2 summarizes the structures of the surfactants employed in this report. These are all anionic surfactants with phosphoric or sulfosuccinate groups and different types of hydrophobic chains. 

Laboratory Treatments. Colorfastness of the dyed wool samples was determined in aqueous and nonaqueous media. Colored samples were cut into 2- X 2-in. squares and sandwiched between multifiber fabrics (Test Fabrics) and undyed wool fabrics of the same dimensions. The fabrics were loosely sewn together by hand with white cotton thread. Two surfactants were chosen for the aqueous treatments Tergitol NPX, a nonionic ethoxylated nonylphenol (Union Carbide) and Orvus WA, an anionic sodium alkyl sulfate (Proctor Gamble). Solutions of 0.1% surfactant in distilled water were prepared. Tests were run in 250-mL Erlenmeyer flasks at a liquor-to-cloth ratio of 50 1. The flasks were placed in an Eberbach constant-temperature shaker bath adjusted to 30 °C and an agitation of 40 cycles/min. Treatment time was 1 h, after which the samples were opened and allowed to dry on blotter paper. This same procedure was used for the nonaqueous treatments. Commercial grade tetrachloroethylene (R. R. Street Co.) with and without 1% Aerosol OT, the anionic surfactant sodium sulfosuccinate (Aldrich Chemical) was selected. The treated samples were removed from the liquids, opened, and dried on blotter paper in a ventilated hood. 

A great variety of chemical reactions can be advantageously carried out in microemulsions [860-862]. In one of the first papers in this field, Menger et al. described the imidazole-catalyzed hydrolysis of 4-nitrophenyl acetate in water/octane microemulsions with AOT as an anionic surfactant [=sodium bis(2-ethyl-l-hexyl)-sulfosuccinate] [864]. The solubilized water, containing the imidazole eatalyst, is confined in spherical pools encased by surfactant molecules, which have only their anionic head groups (-SOb ) immersed in the aqueous droplets. When the ester, dissolved in water-insoluble organic solvents, is added to this water/octane/AOT/imidazole system, it readily undergoes the catalysed hydrolysis under mild reaction conditions (25 °C). 

When a single chain anionic surfactant (such as sodium dodecyl sulfate, SDS) is used, it generally requires a cosurfactant for the formation of a microemulsion. A cosurfactant may not be needed to form a microemulsion if nonionic surfactant(s), certain types of cationic surfactants, or double-chain surfactants such as sodium l,4-bis(2-ethylhexyl)sulfosuccinate (Aerosol OT or simply AOT) are used. 

The spectroscopic probe pyridine-N-oxide was used to characterize polar microdomains in reverse micelles in supercritical ethane from 50 to 300 bar. For both anionic and nonionic surfactants, the polarities of these microdomains were adjusted continuously over a wide range using modest pressure changes. The solubilization of water in the micelles increases significantly with the addition of the cosolvent octane or the co-surfactant octanol. Quantitative solubilities are reported for the first time for hydrophiles in reverse micelles in supercritical fluids. The amino acid tryptophan has been solubilized in ethane at the 0.1 wt.% level with the use of an anionic surfactant, sodium di-2-ethylhexyl sulfosuccinate (AOT). The existence of polar microdomains in aggregates in supercritical fluids at relatively low pressures, along with the adjustability of these domains with pressure, presents new possibilities for separation and reaction processes involving hydrophilic substances. 

The ELM method has been found to be very successful for the extraction of proteins [80]. Solubilization of several biomolecules with surfactants into reversed micehes, only two have received sufficient attention for use the anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (known... 

SDDBS and AOT denote the anionic surfactants sodium dodecyl-benzenesulfonate and sodium dioctyl-sulfosuccinate, respectively. Triton X-100 is the nonionic surfactant nonylphenol decafethylene-glycolether). Compound 1 is a mixture of sihcone oil and hydropho-bized silica Compound 2 is an emulsion of Compound 1, which contains also solid particles of Span 60. Data from References 684 and 687. 

FIGURE 5.64 Consecutive cycles of exhaustion and reactivation of mixed oU-silica compound in 10mM solution of the anionic surfactant sodium dioctyl-sulfosuccinate (AOT). An initially active antifoam (defoaming time 5 s) gradually loses its activity with the number of foam formation/destruction cycles in a standard shake test. The introduction of silicone oil results in a perfect restoration of the antifoam activity. Five exhaustion curves (indicated by roman numbers the symbols indicate the experimentally measured defoaming time) and the corresponding four reactivation events (the vertical dashed lines) are shown. (Adapted from Denkov et ah, Langmuir, 16, 2525, 2000.)... 

Hales, S.G. (1993) Biodegradation of the anionic surfactant dialkyl sulfosuccinate. Environ. Toxicol. Chem., 12(10), 1821-1828. 

The negatively charged hydrophilic headgroup of the anionic surfactants may comprise sulfate, sulfonate, sulfosuccinate or phosphate groups attached to an extended hydrophobic backbone [82]. The nature of the hydrophilic group will influence the extent of electrostatic stabilization, the behaviour of the surfactant as a fiinction of pH, the degree of hydrolysis, and the variation of latex stability with time, electrolyte and temperature conditions. The nature of the backbone hydrophobe will influence the adsorption behaviour of the surfactant onto the latex particle surface, its cmc value, the interfacial tension (which affects monomer emulsification), and the extent of steric stabilization, among other factors. 

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. 

T012 Mazawet IT, MERPOL HCS Monawet MM-80 Monawet MT-70E NIaproof Anionic Surfactant 4 Nonoxynol-2 Nonoxynol-3, Nonoxynoi-5 Nonoxynol-7 Nonoxynol-8, Nonoxynoi-11 Nonoxynol-13 Nonoxynoi-15 Nonoxynoi-28, Nonoxynol-40, Nonoxynol-58, Nonoxynol-108, Octoxynol-3, Octoxynol-8, Octoxynoi-18, Octoxynol-IS Octoxynol-30 Oleoyl sarcosine PEG-15 cocamine, PEG-B cocoate PEG hydrogenated castor oil, PEG-30 tetramethyl decynedbl Pentex 99 Plurafac RA-40 Pluronlc L92 Polysorbate 28, Polysorbate 81 Rhodacal 330 Rhodafac RE-960 SECOSOL DOS 70 Sodium dinonyl sulfosuccinate Sodium dodecylbenzene-sulfonate Sodium myristyl sulfate. 

One can conceive that an anionic surfactant like sodium-di-2-ethylhexyl-sulfosuccinate (NaAOT) or sodium dodecyl sulfate (SDS) can be called so in working terms when the positively charged counterion, sodium, gets detached from the molecule and is released into the solvent in which the surfactant is dissolved. The same is true for the surfactant cetyltrimethylammonium bromide (CTAB) in which case the negatively charged bromide ion should be detached from the molecule so that the latter can become cationic . 

---