Phase in water

The trichloro derivative reacts rapidly at room temperature with sulfide, hydrosulfide, alkylmercaptide, or thiophenoxide ions in the solid phase, in water, or in organic solvents. 

There are a number of industrially important reactions where two liquid phases are involved and the aqueous phase contains ionic species. Here the rate may be severely limited due to low solubiblity of the reactant, located in the organic phase, in water. We would benefit from using a pha.se-transfer (PT) catalyst, which ferries the ionic species into the organic phase thus overcoming a severe limitation. Such PT catalysts are typically quaternary ammonium compounds like tetrabutylammonium halides, trioctylmethylammonium chloride, etc. (see also Section 3.8). 

The volumetric ratio of the two liquid phases (j6 = Forg/ Faq) can affect the efficiency of substrate conversion in biphasic media. The biocatalyst stability and the reaction equilibrium shift are dependent on the volume ratio of the two phases [29]. In our previous work [37], we studied the importance of the nonpolar phase in a biphasic system (octane-buffer pH 9) by varying the volume of solvent. The ratio /I = 2/10 has been the most appropriate for an improvement of the yield of the two-enzyme (lipase-lipoxygenase) system. We found that a larger volume of organic phase decreases the total yield of conversion. Nevertheless, Antonini et al. [61] affirmed that changes in the ratios of phases in water-organic two-phase system have little effect upon biotransformation rate. 

A bioslurry phase system consists of the suspension of a solid phase in water or other liquid medium to a concentration typically between 5% and 40% (w/v) and kept under agitation conditions to allow the microbial growth of the indigenous microbiota or a particular inoculated microorganism [114], Bioslurry systems for bioremediation purposes have been mostly conducted with bacterial cultures [146, 147], although in the last few years WRF were also successfully applied to soil bioremediation of PAHs, hexachlorocyclohexane and pentachlorophenol [110, 113, 114],... 

Table 15.1 Concentration factors for organometallics and inorganic ions between sediments and liquid phases in water... 

Fig. 3 Concept of the ion-association method for fabricating ion-based organic dye nanoparticles in pure aqueous media. The approach is based on ion-pair formation between the ionic dye (for example, cationic dye) and the hydrophobic counterion that is soluble in water [for example, tetraphenylborate (TPB) or its derivative anion], which gives rise to a hydrophobic phase in water. For preparation, organic cosolvent is unnecessary. The size of the dye nanoparticles can be controlled by adjusting the interionic interaction between the dye cation and the associative hydrophobic counteranion...

These results showed an important feature of the dicarboxylic acid in question. Contrary to the corresponding monocarboxyllc acid, it prevents the formation of a liquid crystalline phase in water-poor systems. The implications of this fact for the formulations of liquid cleaners is obvious. 

N. Garti, S. Magdassi, and D. WhitehUl Transfer Phenomena Across the Oil Phase in Water-Oil-Water Multiple Emulsions Evaluated hy Coulter Counter 1. Effect of Emulsifier 1 on Water Permeahihty. J. CoUoid Interface Sci. 104,587 (1985). 

Reclaim is a passive, in situ technology that uses a hydrophobic porous polymer to attract, adsorb, and concentrate petroleum hydrocarbons and volatile organic compounds (VOCs) from soils and/or groundwater. Reclaim is considered a passive treatment technology because it requires no mechanical equipment remediation consists of placing polymer-filled canisters in recovery wells and allowing the containers to attract and adsorb organic contaminants. Reclaim canisters are then recycled and contaminants recovered for analysis and/or disposal. This polymer extracts contaminants whether they are in liquid phase, vapor phase or dissolved phase in water. 

Table 6-2 Three-phase systems classified by the state of the third phase in water.

State of Third Phase in Water/in System. .. Gas/Water/Solvent Gas/Water/Solid... 

Dispersion of Solvent (third phase) in Water/Reactor Solvent Solute (M) References... 

Figure 183. Drums with coalescers for assisting in the separation of small amounts of entrained liquid, (a) A liquid-liquid separating drum equipped with a coalescer for the removal of small amounts of dispersed phase. In water-hydrocarbon systems, the pot may be designed for 0.5 ft/sec (Facet Enterprises, Industrial Division), (b) An oil-water separator with corrugated plate coalescers (General Electric Co.).

Figure 1. Electrical conductivity of liquid crystalline phases in water-sodium lauryl sulfate (Curve 1) and water-potassium laurate (Curve II) systems (27).

The rubber particle size in the final product increases several fold if the prepolymerization is carried out in the presence of a dilute aqueous solution of an alkane sulfonate or polyvinyl alcohol in place of pure water. The addition of a surface-active agent converts the coarsely dispersed oil-water mixture—obtained as above in the presence of pure water—into an oil-in-water emulsion. In this case even prolonged stirring during prepolymerization does not decrease the rubber particle size appreciably in the final product. The stabilization of the droplets of the organic phase in water by the emulsifier obviously impedes or prevents agitation within the polymeric phase. Figure 1 shows the influence of these three prepolymerization methods (under otherwise equal reaction conditions) on the dispersion of rubber particles in polystyrene. 

The C12-(EO)9-MA macromonomer was found to be a very effective emulsifier for BzMA in water even at a concentration less than 5 wt%, to give a stable milky emulsion [42,96]. Table 3 shows that the rate of polymerization depends on the initiator type and polarity of continuous phase. In water solution, the rates are several times higher than in heptane. The rate of polymerization increases with increasing macromonomer concentration in systems with KPS and AIBN, and it is constant with AVA. The higher the macromonomer concentration, the higher the particle concentration and rate of polymerization. These results indicate that distribution of the initiator between the phases influences in complex way the polymerization and nucleation mechanism. 

As compared with water, ammonia s increased ability to dissolve hydrophobic organic molecules suggests an increased difficulty in using the hydrophobic effect to generate compartmentalization in ammonia, relative to water. This in turn implies that the liposome, a compartment that works in water, generally will not work in liquid ammonia. Hydrophobic phase separation is possible in ammonia, however, albeit at lower temperatures. For example, Brunner reported that liquid ammonia and hydrocarbons form two phases, where the hydrocarbon chain contains from 1 to 36 CH2 units.5 Different hydrocarbons become miscible with ammonia at different temperatures and pressures. Thus, formation of ammonia-phobic and ammonia-philic phases, analogous to the hydrophobic and hydrophilic phases in water, useful for isolation would be conceivable in liquid ammonia at temperatures well below its boiling point at standard pressures. 

The intermediate reaction that yields Al(OH)3 arises in all these cases because it is in near thermodynamic equilibrium with alumina phases in water. 

Su oemulsions are defined as a mixture of a dispersed solid phase and an emulsified oil phase in water as the continuous or bulk phase. The solid phase is a solid, water insoluble active ingredient, the oil phase a liquid pesticide in pure form or dissolved in a water insoluble solvent. The oil phase can sometimes also be an oil or adjuvant. Suspoemulsions are a relatively new formulation type as becomes evident by the fact that a FAO specification was established only as late as 1997. At the same time specific evaluation methods were officially published (CIPAC MT 180) [2]. 

Table 9.1. Correlation between ion potential of the cation of oxide and maximal volume concentration of the solid phase in water-ceramic suspension [8].

A position to the right of the microemulsion area means the presence of a lamellar liquid crystal as has been repeatedly demonstrated by Ekwall (19). The temporary appearance of liquid crystals when W/0 microemulsions are brought into contact with water have, with this result, been given a satisfactory explanation. The faster transport of the surfactant into the aqueous layers gives rise to temporarily higher surfactant concentrations and the stability limits for the water rich W/0 microemulsions phase are exceeded towards the liquid crystalline phase in water. 

---