Phosphates and Borates

Organic derivatives of both boric acid and phosphoric acid have been proposed as filler treatments especially for use on calcium carbonate. 

These organophosphates were used to coat both precipitated and ground calcium carbonates, and the coated fillers were assessed in SBR and EPDM elastomers. Coating was by adding an aqueous or organic solution of the phosphate modifier to an aqueous 

Despite the apparent promise of this approach, there seems to be little or no commercial use of this type of coating. The additives are probably expensive to prepare and the benefits obtainable may not then warrant their use. 

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Another class of inhibitors in near-neutral solutions act by stabilising oxide films on metals to form thin protective passivating films. Such inhibitors are the anions of weak acids, some of the most important in practice being chromate, nitrite, benzoate, silicate, phosphate and borate. Passivating... 

Combined condensation of melamine and of the acid residue is also shown by the phosphate and borate. In these cases however, the polymeric dehydrated compound derived from the acid is thermally stable up to above 500 C allowing chemical reactions with melamine condensation products simultaneously formed. The resulting material is stable to 950 C (phosphate, ca 30% of original salt) or to above 1100 C (borate, ca. 20% of original salt). 

VIOLET Potassium compounds other than silicates, phosphates and borates rubidium and cesium are similar. Color is masked by lithium and/or sodium, appears purple-red through cobalt glass and bluish-green glass. 

Lumpkin G. R. and Ribbe P. H. (1983). Composition, order-disorder and lattice parameters of olivines Relationships in silicate, germanate, beryllate, phosphate and borate olivine. Amer. Mineral, 68 164-176. 

The most efficient system devised by Monsanto uses electrodes fabricated from carbon steel plate, electro-coated on one face with cadmium. These are stacked in parallel so that the electrolyte can be pumped through the gap between successive plates. Overall tire system forms a series of electrochemical cells with a cadmium cathode and a carbon steel anode. Each plate of metal forms the cathode of one cell and the anode of the next in the stack. Electric current is passed across the stack. The electrolyte contains phosphate and borate salts as corrosion inhibitors, EDTA to chelate any cadmium and iron ions generated by corrosion together with hex-amethylenebis(ethyldibutylammonium) phosphate to provide the necessary telraal-kylammonium ions. This electrolyte circulates through the cell from a reservoir and there is provision for the introduction of acjylonitrile and water as feedstock. The overall cell reaction is ... 

Due to the low conductivity in organic solvents, the currents are found to be orders of magnitude smaller than in aqueous CE. Hence, Joule heating virtually does not occur, even at high background electrolyte concentrations up to 0.1 mol/L. This allows us to work at a very high separation voltage. Nevertheless, the ability of a solvent to dissolve ionic species limits the number of solvents that can be used in CE. For instance, common buffer ions used in aqueous CE, such as phosphate and borate, cannot be employed... 

Although dated, the following example illustrates the fact that size-exclusion chromatography can be conducted efficiently and reliably under high pressure using a less conventional solvent system (TEAP) than the acetate-, phosphate-, and borate-based buffers described in the manufacturers catalogues 66 ... 

Since phosphate and borate buffers are well described in the literature, the power of CZE in peptide chemistry will be illustrated with two examples that emphasize less conventional conditions than those offered by the manufacturers, such as using TEAP solvent systems or standard buffers in the presence of MeCN. These were utilized for some unusual separations. 

Wegh et al. (2001) studied the Nd3+ emission spectra for several phosphate and borate systems upon VUV excitation of the 4f25d levels. They observed 4f25d 4f3 fluorescence from... 

Small, fluorinated organic anions, such as trifluoromethanesulfonate (or triflate) and trifluoroacetate, were quickly considered as alternatives to inorganic fluorinated phosphates and borates. Carlin and coworkers were the first to report... 

The use of buffers and pH adjustment is an important consideration in lens care products. It is a general practice that all products which are likely to come in direct contact with ocular tissues should be buffered for ocular comfort around physiologic pH and preferably in the range 6-8.0. The most commonly used buffers in contact lens care products are phosphates and borates. Buffers used occasionally are acetate, citrate, and others. Besides buffers, sodium hydroxide and hydrochloric acid are generally used to achieve a desirable pH in the final product. They are also used to adjust the final pH in products, which do not have any buffering system. The selection of an appropriate buffering system should consider the pH necessary for optimal performance of the product, as well as products... 

As shown in Figure 13.19a, phosphate and borate inhibit the dissolution of goethite by H2S. Similarly, the dissolution of lepidocrocite (7-FeOOH) by EDTA (Y" ) is inhibited by phosphate and arsenate (Figure 13.19b). Both in the reductive dissolution (by H2S) and the ligand-promoted dissolution (by... 

In aqueous solution, phosphate, borate, and carboxylate buffers are applicable, but in mixed solvents the solubility of phosphate and borate buffers is low in such mixtures, carboxylate buffers may be used in slightly acid, and amine buffers in slightly alkaline medium. To avoid excessive buffer concentrations it is advisable to maintain pH in the bulk of the solution constant by means of a pH-stat. 

The rate constant ki calculated in this way is subject to general base catalysis according to the relation ki = k Q -f oh[OH ] -f- S The calculated curve (Fig. 21) using determined catalytic coefficients for hydroxide, phosphate and borate ions, agrees well with experimental points. Other methods (Bell and Evans, 1966) give values of rate constants of comparable magnitude. 

Synthetic fluids including ethanolamines, nitrates, nitrites, phosphates, and borates [H], as well as alcohol and ester surfactants [L]. 

Relaxation behaviour (discussed in chapter 9), of both electrical and mechanical properties, has been studied in phosphate and borate systems. Increased concentration of Agl shifts the mechanical relaxation peaks to lower temperatures at constant frequencies and no new peak was observed which could be associated with a separate population of mobile Ag ions. The relaxed modulus, however, extrapolates to that of the... 

The concentration of alkali metal and ammonium salts influences the colour reaction the absorbance decreases as ionic strength increases. Thus the concentrations of salts, as well as the pH, should be matched in sample- and standard solutions. Phosphate and borate buffers are recommended. 

Energy transfer between Ce3+ and Tb3+ in borate glasses was studied by Reisfeld and Hormadaly 22), the evidence of energy transfer is presented in Fig. 1. Energy transfer between Ce3+ and Tm3+ in phosphate and borate glasses was detected by Reisfeld and Eckstein 23) and the evidence of such transfer is presented in Fig. 2. Energy transfer be-... 

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