PolyPhosphates, sodium

Sequestration forms the basis for detergent and water-treatment appHcations of polyphosphates. Sequestration of hardness ions by sodium tripolyphosphate used in detergent formulations prevents the precipitation of surfactants by the hardness ions. Sodium polyphosphate glass (SHMP) may be added to water system to prevent the formation of calcium or magnesium scales by reducing the activity of the hardness ions. However, if the ratio of cation to polyphosphate is too high at a given pH, insoluble precipitates such as may result instead of the soluble polyphosphate complexes. The... 

The decomposition of dithionite in aqueous solution is accelerated by thiosulfate, polysulfide, and acids. The addition of mineral acid to a dithionite solution produces first a red color which turns yellow on standing subsequentiy, sulfur precipitates and evolution of sulfur dioxide takes place (346). Sodium dithionite is stabilized by sodium polyphosphate, sodium carbonate, and sodium salts of organic acids (347). 

The complex preparative interrelationships occurring in the sodium polyphosphate system are summarized in Fig. 12.21 (p. 531). Thus anhydrous NaH2p04, when heated to 170" under conditions which allow the escap>e of water vapour, forms the diphosphate Na2H2p207, and further dehydration at 250" yields either Maddrell s salt (closed system) or the cyclic trimetaphosphate (water vapour pressure kept low). Maddrell s salt converts from the low-temperature to the high-lemperaturc form above 300", and above 400" reverts to the cyclic... 

Sodium fluoride also attacks silica, as do sodium metaphosphate and sodium polyphosphate, and to a lesser extent sodium carbonate and sodium cyanide. Attack is particularly vigorous for fused alkalis, alkali halides and phosphates. 

Figure 10.1 Types of phosphate structures, (a) Where x = 12 to 14, the structure represents sodium polyphosphate, a phosphate typically used in HW heating and industrial steam boiler formulations. The structure is ill defined and described as glassy rather than crystalline. Where x = 2, it represents sodium tripolyphosphate, (b) This is the structure where effectively, x = 0, and represents trisodium phosphate (sodium orthophosphate), which is commonly supplied in either crystalline or anhydrous powder form and used as an alkalinity booster, boiler boil-out cleaner, and metal surfaces passivator.

The luminescence of macrocrystalline cadmium and zinc sulfides has been studied very thoroughly The colloidal solutions of these compounds also fluoresce, the intensity and wavelengths of emission depending on how the colloids were prepared. We will divide the description of the fluorescence phenomena into two parts. In this section we will discuss the fluorescence of larger colloidal particles, i.e. of CdS particles which are yellow as the macrocrystalline material, and of ZnS particles whose absorption spectrum also resembles that of the macrocrystals. These colloids are obtained by precipitating CdS or ZnS in the presence of the silicon dioxide stabilizer mentioned in Sect. 3.2, or in the presence of 10 M sodium polyphosphate , or surfactants such as sodium dodecyl sulfate and cetyldimethylbenzyl-ammonium... 

Sodium phosphate(s), 28 831-834, 29 18 carbon dioxide by-product of manufacture, 4 810 economic aspects of, 28 860 uses for, 28 833-834 Sodium polybutadiene, 9 555, 556 Sodium polymetaphosphate, 8 416 Sodium polyphosphates, 9 16 manufacture of, 28 858 Sodium polyphosphate glass, 28 851 Sodium polystyrene sulfonate cosmetic surfactant, 7 835t Sodium polysulfide(s), 23 640 in sodium production, 22 773 Sodium-potassium eutectic, 15 252... 

An evaluation of numerous clays, including kaolins and bentonites of comparable particle size and distribution, revealed a wide variation in the properties of LDEE-clay composites prepared under identical conditions with similar loadings. This may be attributed to the interference with the radical reactions involved in the coupling sequence. This is confirmed, in part, by the finding that the most effective clays were those which were reported to have been treated with sodium polyphosphate to improve their dispersibility in water during papermaking processes. Solomon reported (1) that treatment of the clays which inhibited radical reactions with sodium polyphosphate reduced the inhibition. 

Addition of sodium polyphosphate appreciably altered the rate constants for reactions (19)—(21) and stabilized the small non-metallic silver clusters [512, 513]. Advantages of the steady-state and pulse-radiolytic approaches to silver-cluster formation are manifold. Firstly, experimental conditions can be precisely adjusted such that the reactive species is exclusively e or, alternatively, that it is a known alcohol radical. Secondly, the concentration of the reducing species (the number of reducing equivalents generated) is readily calculable. Thirdly, in time-resolved experiments, rate constants for the individual reaction steps can be determined by monitoring absorption and/or conductivity changes. These latter determinations permitted the assessment of agglomeration numbers [512,513]. 

The gel was prepared by mixing 66 ml of gel buffer (0.01 M Cd(C104)2, 0.01 M sodium polyphosphate, pH 11) 7.4 ml acrylamide solution (44.4 g of acrylamide, 1.2 g of methylene-bisacrylamide in 100 ml water) and 62.4 ml water in round bottom flask and deaerated for 5 min with a water pump. Then 1.2 ml of freshly prepared ammonium persulfate solution (150 mg in 10 ml water) and 0.1 ml of N,N,N, N tetramethylethylenediamine (TEMED) were added and mixed carefully to avoid the introduction of air. Finally, 100 ml of the resulting solution was poured carefully, to minimize the introduction of air, into a 25 mm-diameter tube. The monomer solution was overlayered with water to remove the meniscus and reduce the entry of air. The polymerization was allowed to proceed overnight at room temperature. The resulting gel, having a polymer concentration of 2.5% and a cross-link density of 2.6%, was used in a home made apparatus. ... 

Alternatively, finely powdered zeolites may be used in detergent powders as a builder since zeolite particles smaller than 10 pm do not stick to clothing. Formerly, sodium polyphosphates (Section 7.7) were used extensively as detergent builders to tie up the Ca2+ and Mg2+ in hard water as soluble complexes (or as a precipitate that washes away). However, many communities ban phosphate detergents because of pollution problems (Sections 7.7 and 9.6), thus creating a major new market for zeolites. 

Sodium Carboxymethylcellulose Sodium Citrate Sodium Ferrocyanide Sodium Polyphosphates, Glassy (Sodium hexametaphosphate)... 

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