Zirconium acetate solution

Zinc Sulfate Heptahydrate Zinc Sulfocarbolate Zinc Sulfophenate Zinc Vitriol Zinc Yellow Zirconium Acetate Zirconium Acetate Solution Zirconium Nitrate Zirconium Nitrate Pentahydrate... 

In this work, zirconium acetate solution was used in order to increase the pH of the pillaring solution and the content of sulfate ions introduced. Different preparation parameters and their effect on the structural and textural properties have been investigated. The resulting materials present a best zirconium-sulfate intercalation with higher sulfate rate and develop very high thermal stability of sulfur even at about 830 °C. 

It is known that a zirconyl chloride solution is not stable [11]. The pH of a fresh 0.1 mol/L ZrOCl2 solution decreases from 2.1 to 1.9 after 10 minutes. To study the stability of the zirconium acetate solution, the pH was measured periodically. It was found to be equal to 3.76 and a very weak decrease was observed after two days. These properties could give, besides the non aggressive medium for clay layers, a better reproducibility than the zirconyl chloride solution. The effect of the addition of 2 mol/L ammonium sulfate to the 0.1 mol/L zirconyl chloride solution or to the 0.1 mol/L zirconium acetate solutions on the pH values is plotted in Fig. 1. 

This plot shows two important results. The first one is the absence of precipitation occurring for high SOaiZr ratios for the acetate solution. The second one is the increase of pH of the zirconium acetate solution when the sulfate quantity increases. This increase of pH is probably due to the release of acetate groups in solution substituted by sulfate ions, which is more important than the weak acidity of the ammonium ion. 

The diffraction patterns of dried zirconium sulfate pillared clay obtained after different intercalation times are presented in Fig. 2. These samples were prepared using a 0.1 mol/L zirconium acetate solution with an S04 Zr ratio = 0.5. The clay concentration was 10 g/L, with Clay Zr =10 g/mol, at pH = 4.00. The intercalation was performed at 15 °C. 

Fig. 1. Variation of pH as a function of sulfate to zirconium ratio for 0.1 mol/L zirconyl chloride and zirconium acetate solution at 20 °C.

All samples were prepared using 0.1 mol/L zirconium acetate solution at 15 °C with 42 hours intercalation reaction. The clay suspension pH was fixed at the same value as that of the intercalation solution. The X-ray diffraction patterns of zirconium sulfate pillared clays prepared with different sulfate to zirconium ratios are shown in Fig. 4. This figure shows a shoulder at about 19.5 A for the sample prepared using a S04 Zr ratio equal to 0.125. The 19.5 A spacing corresponds to the intercalation of non sulfated zirconium polycations [13]. Non-drastic loss in surface area is observed when the sulfate to zirconium ratio increases. But the use of zirconyl chloride solution shows a drastic loss of surface area when the SOarZr ratio increases (more than 50 %) [13]. 

Zirconium-sulfate pillared clay prepared with reaction time of 140 hours and using 0.1 mol /L zirconium acetate solution has been analyzed with mass spectrometry. When the sample was heated in air, masses of 17, 18, 44, 48, 64 and 80 were recorded, corresponding, respectively, to OH+, H2O+, COz, SO+, S02" and SO3+. Figs. 7, 8 and 9 show the variation of the different masses with heating temperature. 

Chemical Designations- nonymr Zirconium acetate solution Chemical Formula ... 

Zinc Fluoroborate Zinc Fluoroborate Zirconium Acetate Solution Zirconium Acetate... 

The titania syntheses were carried out using a 0.5 mol/liter titanium tetra-butoxide solution in isopropanol, which was fed into 250 ml of water. After filtration, the samples were dried and calcined at 673 K for 4 h. The PZT samples were prepared using the indicated stoichiometric amounts of titanium tetrabutoxide and zirconium tetrabutoxide in isopropanol, which were cofed with an aqueous lead acetate solution and precipitated using an aqueous (NH4)2C03 solution directly in the inlet of the high-pressure pump. The addition of the solutions was completed after 20 min. The reaction mixture was then processed for an additional 10 min, giving an overall reaction time of 30 min. 

The aqueous chemistry of zirconium is complex and dominated by hydrolysis. One aspect is that polymerization takes place when salt solutions are diluted. The polymeric species can be cationic, anionic, or neutral. Polymers that are formed include ammonium zirconium carbonate, zirconium acetate, and zirconium oxychloride. 

Catalysts preparation. Intercalation solutions were prepared by addition of an ammonium sulfate solution to a fresh zirconium acetate one. The mixture was adjusted to the desired pH using a HCl solution. In another beaker, Na-montmorillonite suspension was adjusted at the same pH than the intercalation solution. 

In a typical synthesis of Zr-Sil-2 (B), a solution of 0.48 g of Zr(acac)4 in 50 g of acetone was added to 21.25 g of TEOS. After stirring for 30 min., 25.95 g of TBAOH was added dropwise. The solution thus obtained was kept under stirring for 1 h. Finally, 27 g of water was added to it. After stirring for 30 min, the clear gel (pH = 12.3) was transferred to a teflon- lined autoclave and crystallized under similar conditions as those of Zr-Sil-2 (A). Samples having different Zr concentrations ( Si/Zr < 300) were synthesized using two different zirconium sources. The resultant material was filtered, washed with deionized water, dried at 383 K and calcined at 823 K for 16 h. All the Zr-Sil-2 samples were treated with 1 M ammonium acetate solution to remove alkali metal impurities. For comparison, a silica polymorph with MEL structure (Silicalite-2) and a Zr-impregnated Silicalite-2 samples were prepared [10]. 

The two-emulsion (reverse) method has been used recently by Lee etal, [185] in an attempt to synthesize spherical zirconia particles under controlled conditions. In the overall scheme, a non-ionic surfactant (Span 85, Span 80, Span 40 or Arlacel 83, i.e. Sorbitan sesquioleate see below for the choice of surfactant) was dissolved in n-heptane. The HLB values of the surfactants varied in the range 1.8-6.7. Aqueous solutions of zirconium acetate or ammonia were added to two parts of the surfactant-oil phase combination the two had identical volumes. Reverse emulsions were prepared by subjecting the above to ultrasonic agitation, and the two emulsions thus produced were then mixed under stirring. The gel particles that formed in the process were separated by using a modified Dean-Stark moisture trap. Figure 4.4 presents the two-emulsion process in which the two complementary emulsions are mixed to obtain gel precipitates in the spherical droplets. 

Procedure. A strip of quantitative filter paper is impregnated with the red zirconium-alizarin solution. The dried paper is moistened with a drop of 50 % acetic acid and then a drop of the neutral test solution is placed on the moist fleck. A yellow spot appears in the presence of fluorides. When only small amounts of fluorine are present, it is advisable to hasten the reaction by warming the paper in steam. 

The same acetate solution can be used for powder preparation. The zirconium acetate powder dried at 60°C for 4 days was crystallized into cubic Zr02 (by XRD) by calcination at 300 to 400°C. The phase transformation to tetragonal and to monoclinic with increasing... 

Geiculescu A.C., Spencer H.G. Thermal decomposition and crystallization of aqueous sol-gel derived zirconium acetate gels effects of the precursor solution pH. J. Sol-Gel Sci. Technol. 1999b 16 243-256... 

Other preparation routes of PZT powders by sol-gel synthesis used lead acetate trihydrate (Pb(OAc)2 3H2O) and zirconium acetylacetonate (Zr(AcCHAc)4) as basic precursors [92]. The solutions were dehydrated at 105 °C for 2h, and after cooling to 80 °C they were mked with the acetate solution of titanium orthotetrabutylate (Ti(OC4H9)4) in the required ratio of Pb Zr Ti = 1 0.53 0.47. A pure perovsldte phase Pb(Zro,s3Tio.47)03 was formed by calcination at 500 °C. 

Carbonates. Basic zirconium carbonate [37356-18-6] is produced in a two-step process in which zirconium is precipitated as a basic sulfate from an oxychloride solution. The carbonate is formed by an exchange reaction between a water slurry of basic zirconium sulfate and sodium carbonate or ammonium carbonate at 80°C (203). The particulate product is easily filtered. Freshly precipitated zirconium hydroxide, dispersed in water under carbon dioxide in a pressure vessel at ca 200—300 kPa (2—3 atm), absorbs carbon dioxide to form the basic zirconium carbonate (204). Washed free of other anions, it can be dissolved in organic acids such as lactic, acetic, citric, oxaUc, and tartaric to form zirconium oxy salts of these acids. 

A typical flowchart for a chelate process is shown in Fig. 2.6.46 In this process, titanium isoproproxide is first added to zirconium butoxide. Acetic acid is then added to the precursor mixture for suppression of hydrolysis. Finally, lead acetate is then added to the solution, followed by the addition of alcohol and water for control of solution viscosity, solution stability, and oligomer formation.46... 

Figure 3.10 XPS spectra in the range from 150 to 200 eV, showing the Zr 3d and Si 2s peaks of the 7.r02/Si02 catalysts after calcination at 700 °C. All XPS spectra have been corrected for electrical charging by positioning the Si 2s peak at 154 eV. The spectra labeled nitrate correspond to the catalysts prepared by incipient wetness impregnation with an aqueous solution of zirconium nitrate, and the spectrum labeled ethoxide to that prepared by contacting the support with a solution of zirconium ethoxide and acetic acid in ethanol. The latter preparation leads to a better Zr02 dispersion over the Si02 than the standard incipient wetness preparation does, as is evidenced by the high Zr 3d intensity of the bottom spectrum (adapted from Meijers et at, [33]).

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