Solubilization study

Solubilization studies on crude oil by ether carboxylates combined with nonionics have been conducted in the presence of varying amounts of CaCl2 [194]. Good solubility can be obtained when the micellar size is 100 nm and is strongly dependent on the CaCl2 concentration. 

Yellow OB dye is an essentially water—insoluble organic and is convenient to use as a solubi1izate. The studies discussed here use Yellow OB -for solubilization studies in mixed sur-factant systems. Yellow OB can solubilize in the hydrocarbon core o-f the micelle as well as among the polyoxyethylene chains in a micelle with non ionic sur-factant. 

All middle phase microemulsion and solubilization studies were carried out in 20 ml centrifuge tubes with Teflon screw caps. Experiments were conducted at controlled room temperature of 22°C. Equal volumes of aqueous surfactant solution and oil (10.00 ml each) were placed in the centrifuge tube. The tube was shaken gently on a wrist action shaker for 20 minutes and allowed to stand for at least 12 hours to ensure equilibrium. The volume of each phase was carefully recorded to within 0.01 mis. The surfactant and oil concentrations were quantified in each phase for a few... 

As an example we show in Fig. 2.13 measurements by Brun et al.43) using a cation exchange electrode. Larsen et al.44,4S) used bromide and chloride specific electrodes for solubilization studies in 0.1 M hexadecyltrimethylammonium chloride or bromide solutions, 76-77% of the counterions are bound, a figure changing only slightly... 

Basically, two types of solubilization studies can be distinguished. In the first type, solubilization is only a tool to incorporate probe molecules into the polysoaps, to learn of the nature of hydrophobic domains available, e.g. their size, form and polarity etc. ( qualitative solubilization ). The majority of such studies employs dye probes whose spectral properties are sensitive to the environment of the chromophore [20, 362-366]. The second, less frequent type... 

According to the studies carried out by V. N. Izmailova et al, the molecules of some proteins and enzymes reveal high capability to solubilize hydrocarbon molecules, which can incorporate into different segments of macromolecules. The solubilization studies, and in particular those of solubilization of hydrocarbons in aqueous solutions of proteins, allows one... 

Solubilization Study by QCM in Liquid and Supercritical CO2 under Ultrasonar... 

QCM technique was applied to the solubilization study in CO2. Basics of QCM were reviewed, and applications of QCM to experiments in static and dynamic systems were conducted. Roughness effect should be considered when measuring absolute mass change. Solubilization of Cu(acac>2 in CO2 was measured, and the diflfiisivity was estimated. Ultrasonic waves enhance solubilization mainly due to acoustic streaming. Co ion solubility in a cyanex-C02 solution was obtained by the QCM technique in a dynamic system... 

QCM technique was applied to the solubilization study in CO2. Based on the experiments, the following conclusions were obtained. 

It is important to note that results from phosphorus solubilization studies involving water-extraction can be markedly influenced... 

Detergent solubilization studies, inhibitor studies, and temperature-activity profiles indicate that at least two distinct D-glucosidases are present in the membranes. One of these D-glucosidases removes the distal D-glucose from (8), and the other D-glucosidase sequentially removes D-glucose from (9) and (10). 

Such a description is supported by solubilization studies, as illustrated in Figure 20.3. We note from this that the solubilization curves in the presence of polymer are shifted to lower surfactant concentrations but are otherwise essentially the same as those without polymer. From the break-points we can deduce the CMC/CAC values which decrease by the same factor as without polymer as the alkyl chain is lengthened. 

In the present work, we report the micellization and clouding of an amphiphilic tricyclic antidepressant drug, IMP (see Scheme 1) in absence and presence of additives (KCl and TX-100). The work presented here is aimed at obtaining a better understanding of the role of the presence of additives in the thermodynamic quantities of micellization and clouding of the drug in absence and presence of additives. With this viewpoint surface tension, conductivity measurements and dye solubilization studies have been performed on aqueous solutions of IMP to determine the cmc of these drugs in presence of different additives. The surface... 

Alam, Md. S. Kabir-ud-Din Qoud Point and Dye Solubilization Studies on the Micellar Growth of Amphiphilic Drug Chlorpromazine Hydrochloride Influence of Electrolytes. Acta Phys. -Chim. Sin., 2008, 24,411-415. 

In Fig. 3.1.3, AA contents of product samples from the conversion-time runs in Fig. 3.1.2 are shown. We note from Section 3.1.2 that for equal monomer charges of S and AA, there is almost equal likelihood of incorporation of S and AA monomers onto growing radical chains. For the runs wherein the AA charge is 6.7-10 wt% of the monomers. Fig. 3.1.3 shows AA contents to be in the order of 30-50 wt%. Even the runs wherein AA charge was as low as 5 wt% relative to the monomers, copolymer samples have at least 10 wt% AA contents. It should be noted that PAA exhibits UCST behavior for both diethyl ether (DEE) and cyclohexane (CHX) solvents used. Based on the discussion in Section 3.1.2, this will result in the incorporation of more AA in the copolymer chain compared to what intrinsic reactivities will predict and this has been observed. In the runs with 6.7-10 wt% AA charge relative to the monomers, AA contents in the copolymer decreased with time at almost the level of 28-36 wt% AA. However, from Fig. 3.1.2, conversions of the CHX-based system are at least twice those of the DEE-based FRRPP systems. This means that longer-time propagation in the FRRPP system is more due to S addition than in the CHX-based system. Thus, FRRPP-based S-AA products were more amphiphilic, as shown by emulsification and solubilization studies (Caneba et al., 2003). 

The amounts of a-D-glucosidase in cells of Bacillus amyloliquefaciens grown on amylaceous polysaccharides were found to be higher than in cells grown on non-carbohydrate carbon sources. By subcellular fractionation and solubilization studies, the a-D-glucosidase was exclusively found to be associated with membranes from ruptured spheroplasts. The purified enzyme (pH optimum 6.8, mol. wt. 2.7 0.1 x 10, temperature optimum 39 °Q hydrolysed maltose, maltotriose, isomaltose, and isomaltotriose at rates slower than for 4-nitrophenyl a-D-glucopyranoside and sucrose. 

Fanun, M. Phase behavior, structure evolution and diclofenac solubilization studies on mixed nonionic surfactants microemulsions. In Colloid and Surface Research Trends. Fong, P.A. (Ed.), Nova Science Publisher, New York, 2007, pp. 107-146. 

In solubilization studies (15), different definitions and concentration units are used. As several quantities could change through a solubilization experiment, the initial, final and reference states have to be defined precisely. Usually, mainly one point of the solubilization isotherm is studied, i.e. the maximum additive concentration (MAC). This concentration is obtained when the solution is in equilibrium with the pure solute. Another easily accessible region is the diluted region of the isotherm where the number of moles of solute per mole of surfactant is low (of the order of 1% maximum). 

Various standard experimental techniques employed in physical chemistry, such as NMR spectroscopy, titration, fluorescence spectroscopy, etc., are used routinely to determine the partition coefficients in solubilization studies, and a large number of publications tabulate the experimental results obtained in terms of equilibrium constants (14, 16). 

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