Aqueous zirconium phosphates

No thermodynamic data relevant to the formation of aqueous zirconium phosphate species was found. 

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NON-AQUEOUS SYNTHESIS OF NOVEL LOW-DIMENSIONAL ZIRCONIUM PHOSPHATES... 

It is known that non-aqueous synthesis has been effectively applied in the preparation of various metal phosphates, including amine-containing aluminum, gallium, indium, zinc and cobalt phosphates with three-dimensional open-framework structures [17-24]. Moreover, phosphates with a layered or chain structure can been crystallized from non-aqueous media [25, 26]. Since the fluoride ions mineralizer was introduced into the synthesis of zirconium phosphates, several zirconium phosphate fluorides with novel structures have also been developed. 

Enones are reduced to saturated ketones by catalytic hydrogenation provided the reaction is stopped following the absorption of 1 mol of hydrogen. " A number of catalysts were found useful for this, including platinum, platinum oxide,Pt/C, " Pd/C, - Rh/C, " tris(triphenylphosphine)rhodium chloride, - nickel-aluminum alloy in 10% aqueous NaOH, and zinc-reduced nickel in an aqueous medium. Mesityl oxide is formed from acetone and reduced in a single pot to methyl isobutyl ketone using a bifunctional catalyst which comprised palladium and zirconium phosphate (Scheme 20). 

Recently, Brzozowska et al. used NR and ex situ electrochemical techniques to characterize an innovative type of monolayer system intended to serve as a support for a bUayer lipid membrane on a gold electrode surface [51]. Zr ions were used to noncovalendy couple a phosphate-terminated self-assembled monolayer (SAM) formed on a gold surface to the carboxylate groups of negatively charged phos-phatidylserrne (PS). This tethered surface was then used for the formation of a PS hpid bilayer structure formed by vesicle fusion and spreading. NR studies revealed the presence of an aqueous environment associated with the tether layer which arises from nonstoichiometric water associated with the zirconium phosphate moieties [52]. 

The solubility of zirconium phosphate, Zr0(H2P04)2, has been studied by von Hevesy and Kimura [25HEV/KIM] in hydrochloric acid solutions. The zirconyl ion does not exist in aqueous solution nor in the solid state (see Section V.2.2) and, as such, the above solid is most likely Zr(HP04)2 H20(cr). The solid was found by these authors to give a saturated solution (as Zr(HP04)2 H20(er)) of 0.00012 M in 6.01 M HCl and 0.00023 M in 10 M HCl. The dissolution of the solid can be described by Reaction (V.70) ... 

All of the members of the final review team contributed, if not text, then comments to all of the chapters of the book. Their primary responsibilities for the different sections/chapters were divided as follows. Paul Brown prepared the introduction, and the sections on elemental zirconium, the zirconyl ion, the gaseous zirconium oxides, zirconium hydride, the halogen compounds and complexes, the chalcogen compounds and complexes, the Group 15 compounds and complexes, zirconium carbides and silicates. He was assisted by Christian Ekberg in the interpretation of aqueous zirconium complexes in these sections. Some initial work was done by Ken Jackson on the zirconium sulphate, nitrate and phosphate compounds and complexes. Bernd Grambow was responsible for the drafting of the sections on zirconium hydrolysis, the ion and the section on crystalline and amorphous zirconium oxides. Enzo Curti drafted the section on the zirconium carbonates. 

Aqueous, chromium-free acidic solutions have also been developed for aluminum materials that may contain complex fluorides of titanium and zirconium, phosphate, and special organic compounds. These solutions are applied by spraying or dipping (up to 60 °C) and produce thin, almost colorless conversion layers with a surface weight < 0.1 g/m. ... 

Simple regeneration with IM HCl leads to the formation of an aqueous suspension of ZrP microcrystals consisting of few layers with respect to the parent material. Pellicles or membranes made up entirely of ZrP can be obtained by filtering the suspension this particular type of ZrP has been called pellicular zirconium phosphate (hereafter ZrP(p,). 

Fig. 46. The dependence of the distribution coefficients of several ions on zirconium phosphate on the aqueous HNO3 concentration. All adsorbates present in tracer amounts. Solutions of Pu(in) were 0.005 in sulphamic acid and 0.015 in Iwdrazine solutions of Pu(IV) 0.02 M in NaNOg and solutions of Pu02 0.02 M in KBrOs. ... 

Vliers et al. have also prepared stable aqueous suspensions of zirconium phosphate and hexylammonium-zirconium phosphate containing [Ru(bpy)3] (99). In the case of zirconium phosphate, there is no interlamellar adsorption of Ru(II) and the cations are located on the external surface. On the other hand, in the case of hexylammonium-zirconium phosphate, [Rufbpyls] was adsorbed in both... 

For the N-alkylated acridine orange cation on colloidally dispersed mont-morillonite (199) and zirconium phosphate (200) in aqueous systems, the orienta-... 

In heterogeneous catalysts, the tailored and pillared cavity is an essential property as it enables the movement of reactants to inner catalytic sites. The mass transfer of reactants and products inside the pores is mainly influenced by the interaction of the internal walls of the channel with organic molecules, and can consequently be controlled by the difference in polarities. To ensure such properties, anchored ruthenium hybrid zirconium phosphate-phosphonates coated with hydrophobic linear double-stranded polystyrene over the inner surface of the Zr layers were prepared by the first complexation of Ru and then molding of inorganic backbone method, and used as the catalyst in the ATH of o-, m- and p-substituted acetophenones (Fig. 42) [121]. This catalyst showed good catalytic activity and enantioselectivity (73.6-95.6 % ees) in the aqueous reduction with FA-TEA as the hydrogen donor, and could retain its catalytic properties after five runs in the case of acetophenone. 

The fact that solid calcium fluoride reacts immediately with zirconium alizarinate renders it possible to detect fluoride in a mixture with phosphates and oxalates. These salts interfere with the detection of fluoride in aqueous solution, because they form either insoluble or complex zirconium phosphates (or oxalates) and thus destroy the red zirconium-alizarin compound and also produce the yellow color. The fluoride in such mixtures may be isolated by treating the alkaline or neutral test solution with calcium chloride the precipitate is ignited and digested with dilute acid. The residue then may easily be tested for fluoride by the zirconium-alizarin solution. ... 

In the tributyl phosphate extraction process developed at the Ames Laboratory, Iowa State University (46—48), a solution of tributyl phosphate (TBP) in heptane is used to extract zirconium preferentially from an acid solution (mixed hydrochloric—nitric or nitric acid) of zirconium and hafnium (45). Most other impurity elements remain with the hafnium in the aqueous acid layer. Zirconium recovered from the organic phase can be precipitated by neutralization without need for further purification. 

Fluoride, in the absence of interfering anions (including phosphate, molybdate, citrate, and tartrate) and interfering cations (including cadmium, tin, strontium, iron, and particularly zirconium, cobalt, lead, nickel, zinc, copper, and aluminium), may be determined with thorium chloranilate in aqueous 2-methoxyethanol at pH 4.5 the absorbance is measured at 540 nm or, for small concentrations 0-2.0 mg L 1 at 330 nm. 

Precipitation of the coating from aqueous solutions onto the suspended Ti02 particles. Batch processes in stirred tanks are preferred various compounds are deposited one after the other under optimum conditions. There is a very extensive patent literature on this subject. Continuous precipitation is sometimes used in mixing lines or cascades of stirred tanks. Coatings of widely differing compounds are produced in a variety of sequences. The most common are oxides, oxide hydrates, silicates, and/or phosphates of titanium, zirconium, silicon, and aluminum. For special applications, boron, tin, zinc, cerium, manganese, antimony, or vanadium compounds can be used [2.40], [2.41],... 

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