Sodium dodecylsulfate surfactant

Data of Siitterlin (22.). Figure 4 shows that EPM is also able to predict the classical Smith-Ewart (2) dependence of the particle number on initiator concentration at high levels of added surfactant (sodium dodecylsulfate =... 

CD-NA rather than by the formation of 1 1 inclusion complexes. It should be noted that addition of the anionic surfactant sodium dodecylsulfate does not induce any photophysical effect. 

The anionic surfactant, sodium dodecylsulfate, SDS, was obtained from Merck, Darmstadt, Federal Republic of Germany. It has a stated purity of 99.99% and was used without further purification. Surface tension measurements gave no minimum in the surface tension at the critical micelle concentration, indicating that the sample did not contain highly surface active impurities. 

A preparation in two steps has been chosen hrst a new hybrid silica precursor P-CDAPS, containing P-CD groups and amine functions, has been prepared and characterized. Then, this precursor has been co-condensed with tetraethyl orthosilicate (TEOS) via a sol-gel process involving the use of surfactant. We chose the anionic surfactant sodium dodecylsulfate (SDS). The chemical and structural characterization combined with adsorption tests of p-nitrophenol and lead nitrate led to the evaluation of the accessibility and the effectiveness of the binding functions in these hybrid materials. 

The major subgroups of anionic surfactants include the alkali carboxylates (soaps), sulfates, sulfonates, and to a smaller degree, phosphates. The esterification of alcohol with sulfuric acid yields probably the best-studied surfactant, sodium dodecylsulfate or SDS. SDS, a sulfate ester, is an extremely effective emulsifier because of its high-electrostatic repulsion. Other sulfates are, for example, sulfated esters from fatty acids, sulfated ethers, and sulfated fats and oils. Sulfonates stem from the reaction of sulfonic acid with suitable substrates. Members of the class of sulfonates are, for example, sulfonic acid salts or aliphatic sulfonates. Other anionic surfactants include substances such as carboxylated soaps and esters of phosphoric acid. 

The effect of surfactants on the autooxidation of different thiols such as 2-mercaptoethanol (ME), 3-mercapto-1,2-propanediol (MPD), mercaptoacetic acid (MAAc) and dodecylmercaptan (DDM) in the presence of a polymeric catalyst, has been studied [155,156]. Fig. 20 illustrates the change in the initial rate of ME oxidation and the change in solution turbidity as a function of the concentration of the added anionic surfactant, sodium dodecylsulfate (DDS). The strong drop in the reaction rate and the increase in the turbidity of the system are apparently due to the formation of a complex between the polyion and the surfactant. However, the nonionic surfactant, oligoethylene oxide, does not influence ME oxidation. 

The anionic surfactant sodium dodecylsulfate (SDS) is by far the most commonly used surfactant in micellar separations. Examples of the use of simple buffered/SDS systems in environmental applications include the simultaneous analysis of 10 A-methylcarbamate pesticides and their hydrolytic phenolic metabolites in river, well, and pond water (pH 8 phosphate/borate buffer/SDS), and the analysis of insecticides (imidacloprid and its metabolite 6-chloronicotinic acid) in air samples collected from a greenhouse cropped with tomatoes (pH 8.5 ammonium chloride/ammonia buffer/SDS). ... 

What is noteworthy about the series is that for the monatomic alkali metal cations their order does not agree with their size or charge density or their lyotropic series (Voet 1937b). This apparent disorder (note the position of Cs+) is not universal, however, since cases where the lyotropic series is followed are also known. An instance is the rate of the penetration of the alkali metal cations through leaf cuticles that decreases in the order Cs+ >Rb+ > K+ > Na+ > Li+, i.e., in the expected order according to their surface charge densities. The cuticular pores were supposed by McFarlane and Berry to be lined with a protein that has exposed positive sites (McFarlane and Berry 1974). The critical micelle concentration (cmc) of sodium dodecylsulphate increases in the reverse order by these cations (Maiti et al. 2009), where Cs+ is at the expected position. The transition of a mixed surfactant (sodium dodecylsulfate + dodecyltrimethylammonium bromide with an excess of the former) from micelles to vesicles (Sect. 4.5) is also promoted in this sequence, explained by counter-ion association depending on relative ease of ion dehydration (Renoncourt et al. 2007). 

Values of V gg determined from the experimental Ah for foam films containing micelles [513,514] using Equation 4.235 are shown in Table 4.7 for three ionic surfactants, sodium dodecylsulfate (SDS, CMC = 8 mM), cetyl trimethyl ammonium bromide (CTAB, CMC = 0.9 mM), and cetyl pyridinium chloride (CPC, CMC = 0.9 mM) at 25°C. As seen in Table 4.7, the micelle aggregation numbers determined in this way compare very well with data for obtained by other methods. 

The oxidation of dextrose by A -bromothalimide in H2SO4 both in the absence and in the presence of surfactants (sodium dodecylsulfate, tritonX-100) is fractional order in dextrose and negative fractional order in H+ the role of anionic and non-ionic micelle is best explained by Berezin s model. ... 

FIGURE 8.37. The change in the solubility of naphthalene as a function of the total concentration of the surfactant (sodium dodecylsulfate). 

The reagent most frequently used for the reduction of hair is thioglycolic acid [68-11-1]. Although a variety of other mercaptans have been screened (51), none has been able to match the unique combination of efficacy, safety, and low cost that is a hallmark of thioglycolic acid. The use of microemulsions and their effectiveness on cystine reduction obtained by thioglycolic acid as compared to water has been investigated. An anionic surfactant, sodium dodecylsulfate, has shown to be less effective than that of water for permanent wave formulations. However, surfactants based on nonionic surfactants are less irritating (52). 

Two relaxation processes were evidenced for a large number of surfactants by using two relaxation techniques or, in favorable instances, a single one. Examples of conventional surfactants sodium dodecylsulfate (shock tube (ST) or ultrasonic relaxation (USR) and p-jump - ) sodium tet-radecyl- and hexadecylsulfates (ST and p-jump ) alkylpy-ridinium sulfates (ST and p-jump ) alkylpyridinium halides (ST and p-jump ) alkylammonium halides (ST and p-jump ) surfactants with divalent counterions (T-jump, p-jump, SF ) two-chain surfactants (USR, SF, and p-jump ) nonionic surfactants (T-jump ). Examples of perfluoronated surfactants perfluorononanoate with various counterions (p-jump, T-jump, and SF ). Examples of dimeric surfactants the alkanediyl-a,co-bis(dodecyldimethylammonium bromide) (p-jump and ST °). 

In this paper, novel method for microencapsulation by coacervation is presented. The method employs polymer-polymer incompatibility taking place in a ternary system composed of two cellulose derivatives, anionic- sodium carboxymethyl cellulose (NaCMC) and nonionic- hydroxypropylmethyl cellulose (HPMC), and anionic surfactant- sodium dodecylsulfate (SDS). In the ternary system, various interactions between HPMC-NaCMC, HPMC-SDS and NaCMC-(HPMC-SDS) take place, which were investigated by detailed conductometric, turbidmetric, tensiometric, viscosimetric, and rheoiogicai study. Interactions were employed to obtain coacervate of controlled rheological properties. Deposition of thus obtained coacervate at the surface of dispersed oil droplets in emulsion and emuision stabiiity were investigated. Emulsions stabilized with coacervate layer of different properties were spray dried and microcapsules in a powder form were obtained. Dispersion properties of microcapsules and microencapsulation efficiency were investigated. 

Yardim Y, Levent A, Keskin E et al (2011) Voltammetric behavior of benzo(a)pyrene at boron-doped diamond electrode a study of its determination by adsorptive transfer stripping voltammetry based on the enhancement effect of anionic surfactant, sodium dodecylsulfate. Talanta 85 441 148... 

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