Solvents cosolvents

The carbometallation of an unsymmetrical alkyne or alkene can lead to two regioisomers (4) and (5) (equation 3). The ratio of (4) to (5) depends on the nature of the organometallic, the organic substrate and the reaction conditions used (presence of a catalyst, solvent, cosolvent, etc.). 

We suggest the following possible reasons for the absence of anion emission in these experiments First, it is possible for water and methanol to form adducts with CO2 which might inhibit their ability to solvate the proton. This possibility was checked using water as a cosolvent in supercritical ethylene, which will not interact with water data do not indicate formation of an anion therefore solvent/cosolvent adducts are not a plausible explanation. Second, perhaps the anion is being formed but is quenched very efficiently. The anion species would be more susceptible to quenching than the neutral molecule. This possibility could be investigated in principle with fluorescence lifetime studies, but this has not been done. It is entirely possible that the anion emission is so weak as to be hidden underneath the tail of the neutral emission. 

Polymers in Binary Solvents. Cosolvency Effect Preferential Adsorption Phenomena... 

In the talk, we present phase behavior data for copolymer-solvent-cosolvent mixtures at temperatures to 300 °C and pressures to 3,000 bar. We also present data on the impact of cosolvents on the phase behavior. 

Ethylene Glycol 1,2-ethanediol 62.07 Solvent/cosolvent increases... 

Solvent + cosolvent Solute Reference Deviation from experimental data ... 

Based on the previous considerations, some authors proposed thermodynamic-based approaches to SAS. De la Fuente Badilla et al attempted to develop a thermodynamic-based criterion for optimum batch antisolvent precipitation (GAS) using a definition of the volume expansion that takes into account the molar volume of the system studied. They analyzed various binary and ternary systems and concluded that the pressure corresponding to a minimum value of the liquid-phase volume expansion coincides with the pressure at which the solute precipitates. In a subsequent work, Shariati and Peters further highlighted the role of SC-CO2 in GAS. It acts as a co-solvent (cosolvency effect) at lower concentrations, whereas at higher concentrations it acts as an antisolvent. 

The algorithm for finding the solute solubility in the mixture of ternary solution (solvent/ cosolvent/solute) is shown in Figure 3. The algorithm starts with known values, such as the physical properties of the solute. After making an initial guess for the solubility, the program obtains the activity coefficients and the new solubility is found and is compared with the old... 

Some interesting features are found for the lattice parameters and aggregate dimensions derived from SAXS for the liquid crystalline phases when gradually exchanging water for another polar solvent. Cosolvents that are shown to have a smaller effect on the lattice parameters (e.g., propylene glycol) will maintain the microstructure and stability of the phase up to high cosolvent-to-water ratios [110]. The block copolymers could be of particular practical relevance for different applications, e.g., within the pharmaceutical area. This prompts investigations of cosolvent-water systems that are acceptable in this context [110,111],... 

We have described the phase behavior of polymer-solvent-cosolvent mixtures where the cosolvent generally increases the solubility of the polymer... 

Meilchen, M. A., B. M. Hasch, S.-H. Lee, and M. A. McHugh. 1991. Poly(ethylene-co-methyl acrylate)-solvent-cosolvent phase behavior at high pressures. Polymer. 33 1922-1925. 

Influence of the reaction conditions (pH, temperature, concentration of substrates, organic solvent/cosolvents) on the reaction system and on the equilibrium constant,... 

Tebol 99. [Arco] t-Butyl alcohol solvent, cosolvent, compatibilizer, coupling agent, processing aid ftn pharmaceuticals, personal care prods., aq. coatings and adhesives, agric. formulations, polymer processing, cleaners/disinfec-tants. 

Cosolvents, entrainers, or modifiers are added to enhance solubilities and solute selectivities. They are normally used at low concentrations, i.e., 1—5 mole %. Methanol is a good example. For nonpolar solutes containing no functional groups, cosolvent-induced solubility enhancement is quite similar for all cosolvents and depends only on cosolvent concentration. This kind of enhancement results from alteration of the solvent properties rather than specific interactions. In the case of polar or heterocyclic solutes, the nature of the cosolvent becomes an important limit on the magnitude of the enhancement factor, e.g., hydrogen bonding or dipole-dipole interactions with the solute. It is these types of specific interactions that make it possible to tailor a solvent/cosolvent mixture to enhance the solubility of a particular solute (18). 

Cosolvents The addition of polar organic solvents (cosolvents) that are completely miscible with, or highly soluble in, water, can significantly change solution-phase activities, such as solubility, sorption kinetics, and transport velocity of organic compounds this is termed the cosolvency effect (Wood et aL, 1990 Brusseau, Wood, and Rao, 1991 Li, Cheung, and Reddy, 2000 Bouchard, 2002). 

When a miscible solvent is added to water, the solvent increases the solubility and decreases the sorption of nonionic organic compounds by reducing the net polarity of the solution. The effect of a cosolvent depends on the nature of the solute and the solvent-cosolvent system, but there is usually a log-linear relationship between chemical aqueous solubility and the volumetric fraction of water-miscible solvent (Wood et al, 1990 Bouchard, 2002). 

ME1 Meilchen, M.A., Hasch, B.M., Lee, S.-H., and McHugh, M.A., Poly(ethylene-co-methyl aciylate)-solvent-cosolvent phase behaviour at high pressures, Po/y/wer, 33, 1922, 1992. 

Chem. Descrip. N-Methyl pyrrolidone CAS 872-50-4 EINECS/ELINCS 212-828-1 Uses Solvent, cosolvent In coatings, stripping/cleaning of paints/vamishes. Industrial cleaning, mold cleaning, petrochem. processing solvent for adhesives, inks, dyes, soaps, metal complexes, agric. solvent for PVAc, PVDF, PS, vinyl copolymers, nylon and aromatic polyamides and polyimides, polyesters, acrylics, PC, cellulose derivs., syn. elastomers, waxes... 

Uses Antistat, binder, emollient, lubricant, emulsifier, vehicle, solvent, cosolvent, stabilizer in cosmetic creams/lotions, deodorants, industrial applies. vehicle in topical pharmaceuticals plasticizer for cellulosics extender for fragrances metal stamping oils defoamer in food-contact paper/paperboard in food-contact textiles Features Oleaginous... 

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