SDS concentration

Figure C2.3.18. Vibronic peak fluorescence intensity ratio (III/I) as a function of SDS concentration for 0.1 % PEO solutions o, —35 000 Daltons —600 000 Daltons). Open symbols are for aqueous solution without added salt, and filled symbols are for 100 mM aqueous NaCl. Reproduced with pennission from figure 2 of [111].

Table 1. Comparison of polymer latexes obtained by emulsion polymerization of 1,4-DVB and S [79], Experimental conditions temperature = 50 °C volume ratio water to monomer = 6.25, SDS concentration = 0.02 M, PPS concentration = 0.01 M. Particle diameters were measured by soap titration and by electron microscopy.

Fig. 5. Electron micrograph of the polymers formed by thermal emulsion polymerization of 1,4-DVB (A) and S (B). SDS concentration = 0.1 M,water/monomer volume ratio =. polymerization temperature = 90 °C. [Reproduced from Ref. 84 with permission, Hiithig Wepf Publ., Zug, Switzerland],...

The catalytic activities of Cu(II), Co(II) and Mn(II) are considerably enhanced by sodium dodecyl sulfate (SDS) in the autoxidation of H2DTBC (51). The maximum catalytic activity was found in the CMC region. It was assumed that the micelles incorporate the catalysts and the short metal-metal distances increase the activity in accordance with the kinetic model discussed above. The concentration of the micelles increases at higher SDS concentrations. Thus, the concentrations of the catalyst and the substrate decrease in the micellar region and, as a consequence, the catalytic reaction becomes slower again. 

Another possibility is to perform CE separation in electrolytes containing high amounts of organic solvents and anionic surfactants (SDS), based on the formation of association complexes between analytes and SDS without micelle formation. As shown in Fig. 2.2.5, SDS concentrations of 40-100 mmol L 1 and acetonitrile contents of... 

A general procedure has been reported by Killian et al. for the incorporation of hydro-phobic peptides into micelles [75]. Therein, the peptides were first dissolved in TFA for deaggregation, dried under nitrogen and redissolved as 5 mM (clear) solutions in TFE or HFIP. The solution is subsequently diluted 1 1 by addition of an aqueous solution containing a varying SDS concentration (typically 500 mM, depending on the protein concentration). Water is then added to yield a 16 1 ratio of water to TFE (HFIP) by volume. Upon addition of excess water the peptide loses its solubility, but at the same time the... 

Additional contact angles were measured at 0.001 M SDS concentration. The hematite disk was conditioned in the SDS solution before adding polymer to the solution. The contact angle was measured after adding sufficient quantities of polymer for concentrations of 1, 3, and 5 ppm. For both PAA and PAM, the contact angle remained constant and identical to the value obtained in the absence of polymer. No polymer was able to adsorb on the surfactant-coated disk. It can be concluded that whichever species, surfactant or polymer, adsorbed first was not... 

Figure 2.5. Evolution of the force with the spacing h for three surfactant (SDS) concentrations. Points correspond to experimental values and solid lines to theoretical predictions. Droplet radius = 94 nm. (Adapted from [10].)...

Figure 5.8. Rate of coalescence as a function of the number density of internal droplets in the globules. Globule diameter =11.5 pm droplet diameter = 0.36 pm initial droplet volume fraction in the globules = 25% globule volume fraction = 10% SDS concentration = 2.4 10 mol/1 SMO concentration in the oil phase = 2 wt% 0.1% of silicone oil with a gyration radius of 12 nm was added to dodecane. (Reproduced from [44], with permission.)...

Limit of Low SDS Concentration and Low Internal Droplet Volume Fraction... 

TABLE 4.4 Mean ( + SD) Concentrations of HHCB and AHTN (ng/g) in Adipose Tissne for 49 Liposnction Patients in New York City... 

Figure 17 Average diameter of gold nanoparticles after laser ablation at 532 nm and a laser fluence of ( ) 320, ( ) 480, and ( ) 1200 mJ pulse as a function of the SDS concentration in the solution. (From Ref 208.)...

Fluorescence probing has also been used by us to investigate the mechanism of vesicle to micelle transformation due to interaction of liposome with sodium dodecyl sulfate micelles. An increase in optical density and hydrodynamic diameter was observed at low SDS concentrations (Fig. 24). The increase was attributed to the incorporation of SDS monomers on liposome vesicles. The point where the hydrodynamic diameter and optical density reached a maximum was proposed to correspond to the saturation of bilayers of the first inflection point. Upon further increase in the SDS concentration... 

Fig. 26 A Model of the preferential dissolution process of PA at low SDS concentration. B Model for the existence of vesicle and mixed micelles at high SDS concentration...

Figure 4 shows the fluorescence intensity of ANS in the SDS-NF mixed aqueous solutions as a function of NF concentration. The SDS concentrations were fixed below and above its CMC. The fluorescence intensity and maximum excitation and emission wavelength of ANS was kept constant even when the concentration of NF increased. This result means that the NF molecules do not penetrate into the SDS micelles. 

The fluorescence intensity of ANS in the SDS-NF mixed aqueous solutions were measured as a function of SDS concentration. The NF concentration was fixed above its CMC. Several fluorescence intensities of ANS at the same SDS concentration agreed with that in the case of the single SDS solution. This result suggests that the mixed micelles can not be formed in the NF and SDS mixed solution, but,rather, that pure component micelles are formed. 

Also, in the case of NF and SDS mixed aqueous systems, the conductivities were measured as a function of the SDS concentration. NF was fixed at several concentrations below and above the CMC. 

The break point corresponding to the CMC of SDS did not shift in several fixed NF concentrations, and the values of equivalent conductivity were almost the same at the same SDS concentration in the mixed solutions. Therefore, it is concluded that the NF molecules can not penetrate into the SDS micelles, and that pure component NF and SDS micelles exist. 

Analysis of NP-EO- o was made by UV-spectroscopy at 275 nm where the phenyl ring gives a strong absorption. The accuracy in the determination of the adsorption of NP-EO- o is about + 0.5 mg/g. The total surfactant concentration was determined by measuring the refractive index increment on a Jena differential refractometer. These measurements give the total surfactant adsorption with an accuracy of about 1 3 tagig. The SDS concentration was obtained from the difference (total surfactant - amount of NP-EO- o) and hence is definitely not known to an accuracy better than 3 mg/g. 

Previously (7) we published a curve which was obtained at intermediate SDS concentration with a somewhat lower styrene concentration and roughly one-tenth of the dose rate. This curve showed a rather good classic form. 

---