Water-hexane system

These results indicate that the sensitized photooxidation of phenanthrene in a two-phase hexane-water system involves the conversion of phenanthrene to 1. 

The nonionic penta(ethylene glycol) dodecyl ether-hexane-water system (Fig. 1) was studied by Friberg and Lapczynska [42]. The reverse micellar droplets have a cylindrical shape in which the surfactant molecules stay parallel to each other, forming a bilayer impregnated with water. 

Conversely, for small volume changes of a hexane/water system with binary mixtures of nonionic surfactants, Mulqueen and Blankschtein [48] found no change in interfacial tension. It should be noted in this case, though, that the difference in phase volumes is probably not enough to show the effect described above, which is only marked when there is a difference of at least several orders of magnitude between phase volumes. 

The measured interfacial tension of benzene-water is only 35 mN m , which is much lower than that of a hexane/water system (51 mN m ) because ... 

Many procedures have been studied for detoxification of aflatoxkis, including heat and treatment with ammonia, methylamine, or sodium hydroxide coupled with extraction from an acetone—hexane—water solvent system. Because ki detoxification it is important to free the toxki from cellular constituents to which it is bound, a stabifi2ation of protekis uskig a tanning compound such as acetaldehyde (qv) or glutaraldehyde may be a solution to the problem (98). 

Terminal activity coefficients, 7°, are noted in Figure 3. These are often called infinite dilution coefficients and for some systems are given in Table 1. The hexane—heptane mixture is included as an example of an ideal system. As the molecular species become more dissimilar they are prone to repel each other, tend toward liquid immiscihility, and have large positive activity coefficients, as in the case of hexane—water. 

In Region II, the high- and low-boihng nodes are MIPK and the MEK-water azeotrope, respectively. The more complicated cyclo-hexane-ethanol-water system (Fig. 13-58c) has three separatrices and three regions, all of which share the ternaiy azeotrope as the low-boiling node. 

Excess Volume Comparison Figure 7.5 compares V for the three systems for which we have compared H, G, and 5, plus the (cyclohexane + decane) system.5 The comparatively large negative for the (ethanol + water) system curve (4) can be attributed to the decrease in volume resulting from the formation of hydrogen-bonded complexes in those mixtures. The negative for the (hexane + decane) system curve (3) reflects an increased packing... 

The results for (cyclohexane + decane) are obtained from J. R. Goates. J. R. Ott, and R. B. Grigg, "Excess Volumes of Cyclohexane 4- u-Hexane. +u-Heptane, -t-n-Octane, + -Nonane, and +u-Decane", J. Chem. Thermodyn.. 11. 497-506 (1979). Excess volumes for the (ethanol + water) system were obtained from K. N. Marsh and A. E. Richards, Excess Volumes for Ethanol + Water Mixtures at 10-K intervals from 278.15 to 338.15 K", Ausr. J. Chem., 33, 2121-2132 (1980). Excess volumes for the (acetonitrile + benzene) and the (hexane + decane) systems were obtained from the same source as the HG and results referenced earlier. 

Data for the hydrogen sulfide-water and the methane-n-hexane binary systems were considered. The first is a type III system in the binary phase diagram classification scheme of van Konynenburg and Scott. Experimental data from Selleck et al. (1952) were used. Carroll and Mather (1989a b) presented a new interpretation of these data and also new three phase data. In this work, only those VLE data from Selleck et al. (1952) that are consistent with the new data were used. Data for the methane-n-hexane system are available from Poston and McKetta (1966) and Lin et al. (1977). This is a type V system. 

IPA-water system, evolving separation strategies for, 22 322-325. See also Water-IPA-hexane system (-)-Ipecoside, 2 84, 85 Ipratropium bromide, 4 360t Iproclozide, 73 49... 

The interaction parameters for binary systems containing water with methane, ethane, propane, n-butane, n-pentane, n-hexane, n-octane, and benzene have been determined using data from the literature. The phase behavior of the paraffin - water systems can be represented very well using the modified procedure. However, the aromatic - water system can not be correlated satisfactorily. Possibly a differetn type of mixing rule will be required for the aromatic - water systems, although this has not as yet been explored. 

Table 5 Overall mass transport coefficients kn and kna values for the mass transport of prenal and citral in the Diphasic system n-hexane/water...

Many reports are available where the cationic surfactant CTAB has been used to prepare gold nanoparticles [127-129]. Giustini et al. [130] have characterized the quaternary w/o micro emulsion of CTAB/n-pentanol/ n-hexane/water. Some salient features of CTAB/co-surfactant/alkane/water system are (1) formation of nearly spherical droplets in the L2 region (a liquid isotropic phase formed by disconnected aqueous domains dispersed in a continuous organic bulk) stabilized by a surfactant/co-surfactant interfacial film. (2) With an increase in water content, L2 is followed up to the water solubilization failure, without any transition to bicontinuous structure, and (3) at low Wo, the droplet radius is smaller than R° (spontaneous radius of curvature of the interfacial film) but when the droplet radius tends to become larger than R° (i.e., increasing Wo), the microemulsion phase separates into a Winsor II system. 

It was necessary to add over 10% buffer for the transesteiification of phosphatidyl choline by native lipase (5). Hydrolysis occurred as a side reaction in the hydrophobic solvent-water system. Tlie transesterification of phosphatidyl choline and eicosapentaenoic acid (EPA) was carried out in water-saturated n-hexane using palmitic acid-modified lipase. Table II shows the transesterification of phosphatidyl choline and EPA. Modified lipase made it possible for the transesterification of phospholipids in organic solvents. 

To illustrate the advantage of this technique, compared either to direct chromatographic analysis of the water system or of an organic solvent extract, we may consider the circumstance of hexane as a hypothetical contaminant. This compound is distributed to the extent of 96% into the gas phase. The implications... 

The first attempt to resolve this problem involved the use of Alog P between two partition systems, namely octanol-water and hexane-water, as a model for the penetration of the blood-brain barrier [29]. This leads back to Seiler s fH value [20] (for details see Section 4.2). 

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