Solubility quaternary systems

Polymerization of butyl acrylate was also studied by us in ethyl acetate/water two phase systems (3) using potassium persulfate/quaternary ammonium salts as the initiator system. Under these conditions (a minimum amount of water was used to dissolve the persulfate), it was found that symmetrical quat salts were more efficient than surfactant type quat salts. Also, the more lipophilic quat salts were more efficient. These results prompted us to propose formation of an organic-soluble quaternary ammonium persulfate via typical phase transfer processes. 

Exchange of potassium or sodium iodide with primary alkyl bromides or chlorides is one of the most thoroughly studied phase transfer reactions173,174. It is normally performed in a two-phase aqueous/organic system utilizing a soluble or a polymer-bound PTC. Starks and collaborators have shown175,176 that primary alkyl chlorides or bromides quantitatively exchange with aqueous sodium iodide in the presence of few mol% of a soluble quaternary ammonium PTC at 108 °C within a few hours (secondary alkyl halides normally yield elimination products under these conditions). The mechanism, which is typical of PTC, comprised two consecutive steps ... 

Patel, P.R, Gregory, T.M, and Brown, W.E. Solubility of CaHP04 2H20 in the quaternary system Ca(OH)2 H3P04-NaCl-H20... 

If the addition of pentane occurs at 60-70% conversion, two influences result an increase in pressure due to the arranged loss of soluble styrene with increasing conversion, and a decrease in pressure because of increasing diffusion of pentane into the beads. The equilibrium pressure for the quaternary system styrene-polystyrene-isopentane-n-pentane has been calculated by Wolfahrt [27] for different conversions, temperatures and //-/isopentane ratios using a thermodynamic sorption model based on chain-of-rotators equation-of-state. 

In an earlier review [3], mixed micelles formed by bile salts were classified into those with (i) non-polar lipids (e.g., linear or cyclic hydrocarbons) (ii) insoluble amphiphiles (e.g., cholesterol, protonated fatty acids, etc.) (iii) insoluble swelling amphiphiles (e.g., phospholipids, monoglycerides, acid soaps ) and (iv) soluble amphiphiles (e.g., mixtures of bile salts with themselves, with soaps and with detergents) and the literature up to that date (1970) was critically summarized. Much recent work has appeared in all of these areas, but the most significant is the dramatic advances that have taken place in our understanding of the structure, size, shape, equilibria, and thermodynamics of bile salt-lecithin [16,18,28,29,99-102,127, 144,218,223,231-238] and bile salt-lecithin-cholesterol [238,239] micelles which are of crucial importance to the solubihty of cholesterol in bile [1]. This section briefly surveys recent results on the above subclasses. Information on solubilization, solubilization capacities or phase equilibria of binary, ternary or quaternary systems or structures of liquid crystalline phases can be found in several excellent reviews [5,85,207,208,210,211,213,216,217] and, where relevant, have been referred to earlier. 

Figure 2. Calculated and experimental solubilities of thenardite (Na2S04) at fixed molalities of NaOH in the quaternary system NaCl-Na2S04-Na0H-H20 at a) 200 C, and b) 300 C. The symbols are experimental data from Schroeder et al. (27). (Reproduced with permission from Ref. 13. Copyright 1988 Pergamon P ess.), ...

Si-B-C-N phase equilibria were calculated by extrapolating from the related unary, binary and ternary systems into quaternary compositions [236, 244, 271-273]. This is valid since no solid solubilities and no quaternary phases exist in the quaternary system. Calculated phase equilibria in the Si-B-C-N system were shown exemplarily by isothermal sections at 1673 K and 2273 K, respectively (Figs. 24a and b). 

A solubility diagram has been constructed for the quaternary system AI(N03)3-Mo03-HN03-H20 4fi9... 

The simultaneous extraction of trivalent chromium, hexavalent chromium, and zinc from cooling lower blowdown water was studied in detail by Fuller and Li. They investigated Alamine 336, an oil-solaUe tertiary amine, and Aliquat 336-S, an oil-soluble quaternary amine salt, both manufactured by General Mills, as carriers in various liquid-membrane systems. Alamine was found to be an effective extractant for Cr , Ct, and Zn. However, for Cr and Cr, a pH of 3.0 or less in the external (feed) phase was required while Zn could be extracted only at a pH > 7. Thus, a combined process could not be developed. Aliquat 336-S was more promising. The chemistry of extraction with this carrier involves the following steps ... 

Mo-Ti-C System. Similarly to the W-Ti-C and W-Ta-C systems, molybdenum carbide is partially soluble in TiC to form a useful material for cemented carbides. As already mentioned, the study of these ternary (and quaternary) systems is outside the scope of this book (for a general review of these systems, see Ref 13). 

Solubility data have been reported for four quaternary systems (a) a section through the NaH2P04-NH,H2P04-(NH4)2HP04-H20 system at 262 to 343 K (13) (b) three... 

Solubility da ta have been reported for several ternary and quaternary systems but in only a few Instances have data for a given system been reported by more than one investigator (s). In three of the systems solid phases other than the components or their hydrates have been reported. 

The KoHPOA-K COi-HyO system. Solubility measurements have been made over the temperature interval of 253 to 353 K (11). Later these same investigators published the solubility polytherm of the quaternary system K2HP0 -K2C03-C0(NH2)2-H20 (12). 

Several ternary and one quaternary systems have been studied but there are insufficient solubility values to enable any to be recommended. 

Since silica dissolves above about pH 10.7-11.0, silicates can be prepared with organic bases having dissociation constants greater than about 10 , although some silica will dissolve in aqueous solutions of weaker bases with constants as low as lO" or 10" (123-125). Merrill and Spencer (124) reported the preparation of a number of water-soluble quaternary ammonium silicates by grinding silica gel with a solution of the free base. However, the compounds all appear to have a ratio of 2 1 when expressed as SiOj (NR )jO by analogy with the alkali metal system. 

The stable phase equilibrium experimental results of solubilities of the quaternary system (NaCl - KCl - Na2B407 - K2B4O7 - H2O) at 298.15 K were determined, and are listed in Table 3, respectively. On the basis of the Janecke index (/b, /b/ [mol/100 mol(2Na+ + 2K+)]) in Table 3, the stable equilibrium phase diagram of the system at 298.15 K was plotted and shown in Figure 5. 

Table 4. Metastable solubilities of the quaternary system (NaQ- KCl - Na2B407 - K2B4O7 - H2O) at 308.15 K...

A comparison of the dry-salt diagrams of the metastable phase equilibrium at 308.15 K and the stable phase equilibrium at 298.15 K for the same system is shown in Figure 8. The metastable crystallization regions of borax and potassium chloride are both enlarged while the crystallized area of other minerals existed is decreased. When compared with the stable system, the solubility of borax in water in the metastable system is increased from 3.13 % to 5.70 %. The metastable phenomenon of borax is obvious in this reciprocal quaternary system. 

Therefore, in this part of predictive solubility of the quaternary system (NaCl - KCl -Na2B407 - K2B4O7 - H2O), the predictive solubilities of this system were calculated on the basis of two assumptions Model I borate in the liquid phase exists all in statistical form of B4O72- i.e. B405(0H)42- Model II borate in the liquid phase exists as various boron species of B405(0H)42-, B3Q3(0H)4-, B(0H)4-. 

According to the equilibria constants and the Pitzer ion-interaction parameters, the solubilities of the quaternary system at 298.15 K have been calculated though the Newton s Iteration Method to solve the non-linearity simultaneous equations system, and shown in Table 9. 

On the basis of the calculated solubilities, a comparison diagram among model I, model II, experimental values for the reciprocal quaternary system at 298.15 K are shown in Figure 9. 

In contrast to water-insoluble alcohols (like pentanol in system A), the melting peaks of water-soluble alcohols in quaternary systems (like butanol in system B) do not coincide with those of the corresponding pure alcohols. The same behavior was observed in system F [82]. Even in a 2.5 wt% water-butanol solution, the melting peak of butanol disappears, presumably because water molecules break the alcohol chain-like structure [82]. Increasing the TC/butanol weight ratio in system F leads to the formation of more free water at the same fixed (total) water content [82]. This phenomenon, which deserves further study, may be assigned to factors such as diminished water solubilization in the continuous phase or a... 

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