NaLS = sodium lauryl sulfate

SDBS sodium dodecyl benzene sulfonate NaLS sodium lauryl sulfate Wq [H20]/[surfactant]... 

It is well known (3,5,6) that sodium lauryl sulfate interacts with some polymers such as polyvinyl acetate causing solubilization of the insoluble polymer leading to an increase in viscosity. In Figure 3, viscosity of the homopolymer and 70/30 VA/BA at various NaLS/polymer ratio is shown. It is seen that the viscosity of the 2% latex dispersion increases with increase in NaLS/polymer ratio. Similar visoosity data for the 85/15 VA/BA was intermediate between the homopolymer and 70/30 VA/BA latexes. Surfactants that showed a normal saturation type adsorption behavior did not show any significant visoosity increase of the latex. 

Figure 1. Adsorption isotherms of NaLS and Aerosol A-102 surfactants at 85/15 VA /BA latex /water interface (17) ((O) sodium lauryl sulfate (A) Aerosol A-102)...

EFFECT OF NON-IONIC SURFACTANT ON THICKENING OF POLYVINYL ACETATE-SODIUM LAURYL SULFATE (NaLS) ( 1)... 

If a photoactive probe molecule is buried in the core of an anionic micelle, biphotonic excitation generates an upper excited state from which electron ejection to solvent can occur. With pyrene (Py) imbedded within a sodium lauryl sulfate micelle (NaLS), for example, electron ejection to form a hydrated electron occurs, Eq. 6 [27],... 

In the case of ionic surfactants (10 8 mol/dm8 sodium lauryl sulfate, NaLS), abrupt transitions from common black films to Newton black films were observed, for NaCl concentrations in the range 0.165—0.31 mol/dm8, by increasing the external pressure.2 The N ewton black films ruptured at a pressure of about 12 x 104 N/m2. 

Micellar effects were found to be variable and dependent on the type of micelle employed. Cationic micelles, such as cetyltrimethylammonium bromide, inhibited hydration. Anionic micelles formed from sodium lauryl sulfate (NaLS) produced a small amount of catalysis at low concentration, exp actually passing through a maximum at [NaLS] < the critical micelle concentration (cmc). On the other hand, micelles formed from monopotassium -dodecyl phosphate in unbuffered water give impressive catalysis relative to water itself. Detailed discussion of these effects is given in Reference 80. 

In order to delve deeper into the similarities and differences between the kinetic behaviors of emulsion polymerization initiated by oil-soluble initiators or water-soluble initiators, Nomura et al. [199-202] carried out extensive investigations into the kinetics and mechanisms of the unseeded and seeded emulsion polymerizations of St at 50 °C using sodium lauryl sulfate (NaLS) as the emulsifier and AIBN as the initiator, and obtained the following conclusions ... 

Most of the work concerned with micellar catalysis of nucleophilic substitution refers to reactions of the Aac2 and SN2 types and will not be reviewed here. To date only a few systems have been examined in which a micellar medium affects the partitioning of solvolytic reactions between unimolecular and bimolecular mechanisms. The effects of cationic (hexadecyltrimethylammonium bromide = CTAB) and anionic (sodium lauryl sulfate = NaLS) micelles on competitive SN1 and SN2 reactions of a-phenylallyl butanoate 193) have been investigated189. The rate of formation of the phenylallyl cation 194) is retarded by both surfactants probably as a consequence of the decreased polarity of the micellar pseudo phase. The bimolec-... 

DSC studies have also been undertaken to investigate the effect of iontophoretic transport of the P-blocker, propranolol hydrochloride on the lipid bilayers of the stratum comeum, pre-treated by two penetration enhancers, sodium lauryl sulfate (NaLS) and hexadecyl trimethylammonium bromide (CTAB). DSC results indicated that NaLS was included into the intercellular lipids during iontophoresis and also showed a slight decrease in the two higher transitions in the SC. Lowering of these lipid endotherms is an indication that the bilayer has increased in fluidity. In the case of CTAB, DSC revealed an increase in the initial skin transition, attributed to the insertion of CTAB into the lipids responsible for this transition. However, pre-treatment of the SC with NaLS proved to be successful in enhancing the flux of propranolol hydrochloride across the SC, while this was not the case for CTAB [17]. 

At an equal interfacial covering of surfactants the mass transfer of acetate is enhanced by a cationic surfactant (dodecyl trimethylammonium chloride, DTACl), unaffected by a nonionic surfactant (octylpolyethylene glycolether, TX100)io and slowed down by an anionic surfactant (sodium lauryl sulfate, NaLS sodiumdodecyl sulfate, NaDdS). This can be quantified when calculating the true interfacial concentrations, mpo,, in the electrochemical double layer with the Boltzmann equation ... 

Figure 12 (a) Pyrene fluorescence in aqueous sodium lauryl sulfate (NaLS) solutions, at NaLS concentrations below and above the... 

Sodium lauryl sulfate (NaLS) was obtained from Fluka and purified from ether. Aerosol-OT (AOT) and n-heptane were also obtained from Aldrich. titanium(IV) tetraisopropoxide Ti[OCH(CH3)2]4 (Aldrich, 97%), cyclohexane (Aldrich), 1-bntanol (Aldrich), and isopropyl alcohol (Aldrich) were purified by distillation. Nanopure water (Bamsted System, USA) was used for making aqneous solntions. 

Duynstee and Grunwald present some experimental data for Reaction (F) in the presence of hexadecyl trimethyl ammonium bromide (CTABr, C = cetyl) and sodium dodecyl sulfate (NaLS, L = lauryl). Sodium hydroxide was the source of OH" in all cases. A pseudo-first-order rate constant of 2.40 x 10-2 s-1 is observed for A CTABr. Use the following absorbance data to evaluate NaLS for this reaction ... 

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