Solubihty ratio

IPs, on the other hand, are uniquely suited for use as solvents for gas separations. Since they are non-voIatile, they cannot evaporate to cause contamination of the gas stream. This is important when selective solvents are used in conventional absorbers, or when they are used in supported Hquid membranes. For conventional absorbers, the ability to separate one gas from another depends entirely on the relative solubihties (ratio of Henry s law constants) of the gases. In addition, IPs are particularly promising for supported liquid membranes, because they have the potential to be incredibly stable. Supported liquid membranes that incorporate conventional liquids eventually deteriorate because the liquid slowly evaporates. Moreover, this finite evaporation rate limits how thin one can make the membrane. This... 

As indicated by equation 35, the vapor pressure—solubihty ratio (eq. 34), only provides accurate results when (/) reliable vapor pressure and aqueous solubihty data are employed, (2) the quantity x is small enough to be neglected, and (3) Henry s law appHes for the dissolved substance in water up to the saturation limit. If water miscibiHty in the organic is expected to be significant, equation 35 is much preferred, assuming miscibiHty data are available (42). This correction can amount to several percent even when the aqueous solubihty is low. For example, water solubihty in -octanol is about 5% whereas the -octanol solubihty in water is in the parts per thousand range. 

As discussed, the separation efficiency is determined by the solubihty ratio of the diastereomeric salts (reflected as the eutectic point in a ternary phase diagram), which depends on not only the resolving agent but also on the crystalline form... 

Numerous studies have probed how novolac microstmcture influences resist hthographic properties. In one example, a series of resists were formulated from novolacs prepared with varying feed ratios ofpara-jmeta-cmso. These researchers found that the dissolution rate decreased, and the resist contrast increased, as thepara-jmeta-cmso feed ratio increased (33). Condensation can only occur at the ortho position ofpara-cmso but can occur at both the ortho- and i ra-positions of meta-cmso. It is beheved that increased steric factors and chain rigidity that accompany increasedpara-cmso content modify the polymer solubihty. 

Terpolymers from dimethy]-a.-methy]styrene (3,4-isomer preferred)—a-methylstyrene—styrene blends in a 1 1 1 weight ratio have been shown to be useful in adhesive appHcations. The use of ring-alkylated styrenes aids in the solubiHty of the polymer in less polar solvents and polymeric systems (75). Monomer concentrations of no greater than 20% and temperatures of less than —20° C are necessary to achieve the desired properties. 

The solubihty of a number of sodium orthophosphates is depicted in Figure 7. Some of the sodium phosphates dissolve or precipitate incongmendy, affording a different Na20/P20 ratio in the solution phase from that of the soHd phase. Sodium phosphates that precipitate are also a function of the temperature. As the temperature increases, the sodium phosphates that may precipitate from solution tend to be anhydrous or lower hydrates than those equiUbrium sodium phosphate phases at lower temperature. Whereas most of the phases in Figure 7 represent congmentiy soluble sodium phosphates, soHd phases appear or disappear upon changes in temperature. 

The general manufacturing scheme for phosphate salts is shown in Figure 11. Condensed phosphates are prepared from the appropriate orthophosphate or mixture of orthophosphates, so the preparation of orthophosphates must be considered first for the manufacture of any phosphate salt. Phosphoric acid is neutralized to form a solution or slurry with a carefully adjusted acid/base ratio according to the desired orthophosphate product. The orthophosphate may be recovered either by crystallization from solution, or the entire solution or slurry may be evaporated to dryness. The dewatering (qv) method is determined by the solubihty properties of the product and by its desired physical properties such as crystal size and shape, bulk density, and surface area. Acid orthophosphate salts may be converted to condensed phosphates by thermal dehydration (calcination). 

It appears that pesticides with solubiHties greater than 10 mg/L are mainly transported in the aqueous phase (48) as a result of the interaction of solution/sediment ratio in the mnoff and the pesticide sorption coefficient. For instance, on a silt loam soil with a steep slope (>12%), >80% of atra2ine transport occurs in the aqueous phase (49). In contrast, it has been found that total metolachlor losses in mnoff from plots with medium ground slopes (2—9%) were <1% of appHed chemical (50). Of the metolachlor in the mnoff, sediment carried 20 to 46% of the total transported pesticide over the monitoring period. 

Small concentrations of vinylcarboxyhc acids, eg, acryhc acid, methacrylic acid, or itaconic acid, are sometimes included to enhance adhesion of the polymer to the substrate. The abihty to crystalline and the extent of crystallization are reduced with increa sing concentration of the comonomers some commercial polymers do not crystalline. The most common lacquer resins are terpolymers of VDC—methyl methacrylate—acrylonitrile (162,163). The VDC level and the methyl methacrylate—acrylonitrile ratio are adjusted for the best balance of solubihty and permeabihty. These polymers exhibit a unique combination of high solubihty, low permeabihty, and rapid crystallization (164). 

Sodium borate solutions near the Na20 B202 ratio of maximum solubihty can be spray-dried to form an amorphous product with the approximate composition Na20 4B202 4H20 commonly referred to as sodium octaborate (64). This material dissolves rapidly in water without any decrease in temperature to form supersaturated solutions. Such solutions have found apphcation in treating ceUulosic materials to impart fire-retardant and decay-resistant properties (see Cellulose). 

From Allyl Ghloride. The hypochlorination of allyl chloride [107-05-1] gives a mixture of the glycerol dichlorohydrins, 2,3-dichloropropanol and 1,3-dichloropropanol about 7 3 ratio. Because of the poor solubiHty of allyl chloride in water, it is essential to minimize the formation of an organic phase in which direct chlorination of the allyl chloride results in the unwanted by-product 1,2,3-trichloropropane. 

Solubility. Sohd—Hquid equihbrium, or the solubiHty of a chemical compound in a solvent, refers to the amount of solute that can be dissolved at constant temperature, pressure, and system composition in other words, the maximum concentration of the solute in the solvent at static conditions. In a system consisting of a solute and a solvent, specifying system temperature and pressure fixes ah. other intensive variables. In particular, the composition of each of the two phases is fixed, and solubiHty diagrams of the type shown for a hypothetical mixture of R and S in Figure 2 can be constmcted. Such a system is said to form an eutectic, ie, there is a condition at which both R and S crystallize into a soHd phase at a fixed ratio that is identical to their ratio in solution. Consequently, there is no change in the composition of residual Hquor as a result of crystallization. 

The anion used to prepare the metal soap determines to a large extent whether it will meet fundamental requirements, which can be summed up as follows solubihty and stabiUty ia various kiads of vehicles (this excludes the use of short-chain acids) good storage stabiUty low viscosity, making handling the material easier optimal catalytic effect and best cost/performance ratio. 

For moderate ratios (<3), the type of emulsion is decided by several factors (5), such as order of addition or type of emulsifier. One Hquid slowly added to the other with agitation usually results in the last-mentioned phase being the continuous one. Another factor is preferred solubiHty of the emulsifier the phase in which the emulsifier is soluble most probably is continuous. 

The imminium chloride formed was transformed, in-situ, into the corresponding carboxyhc acid derivative, this was added to a solution of cellulose in LiCl/DMAc. Palmitic, stearic, adamantane-1-carboxylic, and 4-nitrobenzoic acids were employed. The DS of the corresponding esters increased as a function of increasing the ratio oxalyl chloride/AGU. The solubihty of the products obtained in aprotic solvents was tested GPC results have indicated negligible degradation of the polymer [200]. 

In fact, the solute retention depends on the solubihty parameters of the solute, 8 , of the mobile phase, 8 , of the stationary phase, 8, and of the phase ratio given by Equation 4.7 [24] ... 

The catalyst system Pd(acac)2/TPPTS (TPPTS = trisulfonated triphenylphos-phine) was used in the experiments in which the telomerization of butadiene with ethylene glycol in TMS systems was investigated. However, the catalyst precipitates from many solvent mixtures as a yellow oil or solid, as soon as a homogenous phase is obtained. For this reason the solubihty of the catalyst was determined in various solvent systems. A solution of the catalyst in the mixture of ethylene glycol and water (si) and toluene (s2) was used in a weight ratio of 1 3. The various mediators s3 were added until a clear solution was formed or the catalyst precipitated. Only with DMF or DMSO can a clear solution be obtained. The addition of the catalyst to the polar phase causes an increase in the amount of s3 required to achieve a homogeneous system in the solvent system si toluene DMF the ratio increases from 1 5 4 to 1 5 4.4. 

A number of modifications in the solubility and the partition coefficient terms of the AP have also been proposed in the literature [159-161]. According to these authors the modified absorption potential expressions can be considered better predictors of the passive absorption of drugs than the original AP. The most recent approach [161] relies on a single absorption parameter defined as the ratio of the octanol/water partition coefficient to the luminal oversaturation number. The latter is equal to the solubihty-normalized dose for suspensions and equal to unity for solutions. 

It can be shown [49] for two phases in equihbrium that the partial molar free energies must be equal. In an emulsion (or miniemulsion) there are three phases monomer droplets, the aqueous phase and polymer particles. Since monomer is soluble in all of these phases, the equilibrium condition requires that the three phases have equal partial molar free energies. In the presence of monomer droplets, emulsion polymer particles contain 30-80% monomer in them. Therefore, they are said to be swollen with monomer. Ugelstad et al. [48] and Azad and Fitch [50] have shown that addition of a third water-insoluble component to a swollen polymer particle can increase the monomer to polymer ratio. They have shown that an optimum chain size for the additive exists since the solubihty of the additive increases as the chain size decreases. They found... 

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