Solvent displacement

The 3-cyclohexeityl ion provides another example of the dependence of the extent of rearrangement on reaction conditions. The major product is the result of direct solvent displacement. There is also some product resulting from Itydride shift to the more stable allylic ion as well as a trace of the bicyclo[3.1.0]hexane product arising from participation of the double bond. ... 

Another activation treatment, suitable for most celluloses (although with great variation of the time required, 1 to 48 h) is polar solvent displacement at room temperature. The polymer is treated with a series of solvents, ending with the one that will be employed in the derivatization step. Thus, cellulose is treated with the following sequence of solvents, before it is dissolved in LiCl/DMAc water, methanol, and DMAc [37,45-48]. This method, however, is both laborious, needs ca. one day for micro crystalline cellulose, and expensive, since 25 mL of water 64 mb of methanol, and 80 mb of DMAc are required to activate one gram of cellulose. Its use may be reserved for special cases, e.g., where cellulose dissolution with almost no degradation is relatively important [49]. 

Bychkova V, Shvarev A (2009) Fabrication of micrometer and submicrometer-sized ion-selective optodes via a solvent displacement process. Anal Chem 81 2325-2331... 

For a particle to sediment it must displace an equal volume of the solvent from beneath it. This can only be achieved by centrifugation if the mass of the particle is greater than the mass of the solvent displaced. Hence, density as well as mass is an important consideration and explains the phenomenon of low density particles floating rather than sedimenting during centrifugation. 

Conway et described the most convenient conditions defining standard chemical potentials for adsorption with solvent displacement. First, for n = 1, the conditions are the same as in binary solution thermo-... 

These results clearly show that our solvent displacement process leads to the formation of AmB-lipid structures that are different are from the ribbon-like ones described by Janoff et al. (11,21) for the same composition. It was therefore interesting to investigate the toxicity and efficacy of this formulation. 

Fessi H, et al. Nanocapsule formation by interfacial polymer deposition following solvent displacement. Int J Pharm 1989 55 R1. 

Ag or Cu ions, (b) Schematic representation of the solvent displacement mechanism of MSP dissociation and chain mixing (Lahn and Rehahn 2001). 

Minimal number of repeated steps, for example, extractions Eacile solvent displacements that is, chase lower bp solvent with a higher bp solvent... 

Extensive literature has developed related to the preferential interaction of different solvents with proteins or peptides in bulk solution.156-5X1 Similar concepts can be incorporated into descriptions of the RPC behavior of peptides and employed as part of the selection criteria for optimizing the separation of a particular peptide mixture. As noted previously, the dependency of the equilibrium association constant, /CassoCji, of a peptide and the concentration of the solvent required for desorption in RPC can be empirically described1441 in terms of nonmechanistic, stoichiometric solvent displacement or preferential hydration models, whereby the mass distribution of a peptide P, with n nonpolar ligands, each of which is solvated with solvent molecules Da is given by the following ... 

Use of the Stoichiometric Solvent Displacement Model in Peptide Isolation by Reversed-Phase Chromatography... 

According to this theoretical treatment, the slope of the plots of In k versus the solvent concentration, [3]m, can be employed to derive the contact area associated with the peptide-nonpolar ligand interaction. The retention and elution of a peptide in RPC can then be treated as a series of microequilibriums between the different components of the system, as represented by eq 6. The stoichiometric solvent displacement model addresses a set of considerations analogous to that of the preferential interaction model, but from a different empirical perspective. Thus, the affinity of the organic solvent for the free peptide P, in the mobile phase can be represented as follows ... 

The analyte must be efficiently recovered. The usual mechanism for solvent desorption is selective displacement of the analyte. Selective displacement occurs as a more polar solvent displaces a less polar one on charcoal, just as a more active ion displaces a less active one on ion exchange resins. CS2 is frequently used to recover substances from charcoal, but simple alcohols cannot be displaced from charcoal by CS2, and it is necessary to add l%-5% of another alcohol to the CS2 to facilitate desorption. Frequently, low recoveries can be increased by increasing the quantity of solvent, if analytical sensitivity permits. Prospective solvents may be chosen based on polarity or solubility of the analyte. 

Solvent displacement, and isotherms. 954. 955 Solvent excess entropy at the interface, 912 Solvent interactions, 923, 964 Soriaga, M., 1103, 1146 Specifically adsorbed ions, 886 Spectrometer, 797 Spikes, electrodeposition. 1336 Spillover electrons, of metal, 889 Spiral growth, electrodeposition, 1316, 1324, 1326, 1324,1328 s-polarized light, 802 Srinivasan, S 1439,1494 Standard electrode potential American convention, 1354 convention, 1351 rUPAC convention, 1355 prediction of reactions, 1359 the zinc-minus and copper-plus convention, 1352... 

What does Eq. (6.246) mean This equation represents the adsorption process of ions on metallic surfaces. It includes several conditions that are characteristic of the adsorption process of ionic species, namely, surface heterogeneity, solvent displacement, charge transfer, lateral interactions, and ion size. However, is this equation capable of describing the adsorption process of ions In other words, what is the success of the isotherm described in Eq. (6.246) Figure 6.104 shows a comparison of data obtained experimentally for the adsorption of two ions—chloride and bisulfate—on polycrystalline platinum, with that obtained applying Eq. (6.246). The plots indicate that the theory is able to reproduce the experimental results quite satisfactorily. The isotherm may be considered a success in the theory of ionic adsorption. 

Ribeiro, H.S., Chu, B.S., Ichikawa, S., Nakajima, M. (2008). Preparation of nanodispersions containing P-carotene by solvent displacement method. Food Hydrocolloids, 22, 12-17. 

In adsorption chromatography, solvent molecules compete with solute molecules for sites on the stationary phase (Figure 25-11 and Color Plate 26). The relative abilities of different solvents to elute a given solute from the adsorbent are nearly independent of the nature of the solute. Elution occurs when solvent displaces solute from the stationary phase. 

Table 13 Distinction between D, /d, /a and A Mechanisms for Solvent Displacement Reactions General Rate Law, fc0bs = a6[L ]/(l + b L )...

Displacement chromatogram of a chloroaniline mixture containing 44.7 umol of the meta isomer, 29.8 umol of the ortho isomer and 16.4 umol of the para isgmer. Conditions 50 cm x 4.6 mm ID beta-cyclodextrin-silica column, carrier solvent 10 % v/v methanol water displacer 13 mM p-nitrophenol dissolved in the carrier solvent displacer flow-rate 0.2 mL/min column temperature 30 C. 

Batley, G. E., and Giles, M. S. (1979). Solvent displacement of sediment interstitial waters before trace-metal analysis. Water Res. 13(9), 879-886. 

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