Dodecyl sulfate anion

With a chiral phenylglycinol nucleophile (Scheme 8.4.17), use of the chloride Zincke salt 6 (cf. Scheme 8.4.16) gave decomposition of the salt back to isoquinoline and 2,4-dinitrochlorobenzene. The desired reaction was enabled by exchanging chloride for the weakly nucleophilic dodecyl sulfate anion. The resulting salt 49 also had improved... 

In an electrochemical study of the behavior of the counterions in the mixed cation systems sodium and silver, sodium and calcium, and silver and calcium containing the dodecyl sulfate anion, Corkill and Goodman [102] determined the CMC of sodium, calcium, and silver dodecyl sulfates in water and in solutions of sodium and silver nitrate. 

The ionic associates of malachite green cation with dodecyl sulfate anion has been suggested for monitoring nonionic surfactant levels in industrial wastewaters by spectrophotometric determination at 650 nm [196]. 

In addition, the adsorption properties of organo-LDHs may also be utilized in the preparation of new materials. The intercalation of Ceo molecules into the hydrophobic interlayer of an Mg/Al LDH with intercalated dodecyl sulfate anions has recently been reported [176]. It was found that heating the resulting compound under vacuum in order to decompose the dodecyl sulfate left Ceo molecules sandwiched between the hydroxide layers, although the crystallinity of the sample was poor. 

Ion-pair extraction of an anionic surfactant with a cationic dye such as methylene blue from water into oil is often used for the quantitative analysis of the surfactant in water [57,58]. The surfactant concentration in water is then determined as the dye concentration in the oil or water phase by conventional absorption spectroscopy. Synthetic surfactants such as sulfates and sulfonates completely dissociate in water even at low pH. On the other hand, the association of fatty acid salts (traditional soaps) with H" " depends on the pH. Therefore, the quantitative analysis of surfactants in water is performed by the ion-pair extraction at various pHs. Although quantitative analysis and thermodynamic studies have been already reported for the anionic surfactant/cationic dye extraction, kinetic analysis of the ion-pair extraction has been rarely reported and the extraction mechanism is not discussed in detail. In this section, we describe the kinetic analysis of the extraction of a dodecyl sulfate anion with methylene blue as a typical example using the single microdroplet manipulation and microabsorption methods [59]. In particular, the pH dependence of the ion-pair extraction is discussed. 

Transfer Mechanism of a Dodecyl Sulfate Anion with Methylene Blue... 

The main results presented in this chapter are obtained for macroion suspension defined by the bulk volume fraction of the macroion particles, r) = 0.05, the macroion charge number, Z = 30, the Debye length of the supporting electrolyte, i I) - 2. Such a choice of the parameters makes this model system a suitable prototype of some aqueous ionic micellar solutions such as cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate anionic surfactant (SDS). 

Various types of flame retardant additives have been used in polyamides including magnesium hydroxide - red phosphorus in glass fibre reinforced polyamide [76], chemically modified montmorillonite organoclays [77], surface modified nanosilica [77], carbon nanofibres in polyamides 11 and 12 [78], and dodecyl sulfate anion-modified MgAl (H-DS) interlayers in polyamide 6 [79]. 

Stoichiometric complexes of poly(L-lysine) cations and dodecyl sulfate anions were investigated by Ponomarenko et al. [51,52]. The complexes are prepared by the same method used in the preparation of poly(y,L-glutamic acid)-alkyltrimethylammonium complexes. The secondary stmcture adopted by the polypeptide in these complexes was found to be very susceptible to environmental conditions. In chloroform solution containing 1 to 2% (v/v) TFA the polypeptide chain is in the a-helical con formation whereas a disordered state is present at TFA concentrations above 5%. It was interesting to observe that a noticeable decrease in the spin-lattice relaxation time accompanied the helix-coil... 

Stoichiometric complexes of poly(L-lysine) cations and dodecyl sulfate anions were investigated by Ponomarenko et al. [48,49]. The complexes are prepared by the same method used in the preparation of poly(Y,L-glutamic acid)-alkyltri-... 

We would like to stabilize polystyrene (PS) particles by using either the NPE15 surfactant or the classical SDS (sodium dodecyl sulfate) anionic surfactant. Which surfactant would you use and why (Use the HLB-CPP plot of Problem 7.6.)... 

The Wu and Yang group reported a different type of Pd catalyst (Pd/layered double-hydroxide-dodecyl sulfate anion) which showed a good racemization activity at 55 °C [50]. The Li group showed that the use of Pd nanoparticles modified with various alkalic salts improved the selectivity toward the amine racemization [51]. 

Recently, the DKR of arylamines has been successfully achieved with Pd/layered double hydroxide-dodecyl sulfate anion as racemization agent, a catalyst that was effectively reused more than 30 times without loss of activity and stereodiscrimina-tion [234]. Its high catalytic efficiency allows the reaction to be performed at 55 °C, opening the possibility of working with less thermostable enzymes. In this case, 4-chlorophenyl valerate was used as acyl donor. The search for a novel palladium catalyst... 

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