Titanium hydroxide

Kobayakawa, K., Murakami, K., and Sato, Y., Visible-light active N-doped TiOz prepared by heating of titanium hydroxide and urea, Int.. Photochem. Photobio A Chem., 170,177, 2004. 

Similarly, titanium tetrachloride (TiCl 4) rapidly reacts with moist air to produce a heavy cloud of titanium hydroxide - Ti(OH) - and HCl. 

Infrared spectra suggested that a sulfate ion coordinates to two titanium atoms as a bidentate in particles. The maximum particle size was found at Aerosol OT mole fraction of 0.35 in the mixtures. The particle size increased linearly with increasing the concentration of sulfuric acid at any Wo, but with increasing Wo the effect was the opposite at any sulfuric acid concentration. These effects on the particle size can be explained qualitatively in relation with the extent of number of sulfate ions per micelle droplet. These precursor particles yield amorphous and nanosized TiO particles, reduced by 15% in volume by washing of ammonia water. The Ti02 particles transformed from amorphous to anatase form at 400°C and from anatase form to rutile form about at 800°C. In Triton X-100-n-hexanol-cyclohexane systems, however, spherical and amorphous titanium hydroxide precursor were precipitated by hydrolysis of TiCl4 (30). When the precursor particles were calcinated,... 

Solid superacids may be made by treating ordinary solid add catalysts with strong Br0nsted or Lewis acids. For example, if freshly precipitated titanium hydroxide or zirconium hydroxide is treated with sulfuric acid and calcined in air at 500 °C. a very active solid acid catalyst results. The solids consist mainly of the metal dioxides with sulfate ions coordinated to the metal ions on the surface. Likewise, a superacid solid catalyst can be made by treating these metal oxides with antimony penlafluonde. Both catalysts contain both Br nsted and Lewis acid sites, and they arc sufficiently active to catalyze the isomerization of n-butane at room temperature.26... 

The principal use for the tetrachloride is in pyrots as a smoke agent (called FM ), Ref 5 reports that the tetrachloride. . is extremely reactive resulting in the formation of hydrated oxides, or with atmospheric moisture and, when used for screening, is often disseminated from aircraft spray tanks. Its reaction with water vapor is relatively complex. First, the titanium tetrachloride is hydrated. This reaction is followed by further hydrolysis yielding, finally, titanium hydroxide and HC1. The smoke consists of a mixture of fine particles of solid titanium hydroxide, Ti(0H)4 the hydrated oxide, Ti02-H20 intermediate hydroxychlorides of titanium and dilute HC1 droplets. The sequence of reaction is ... 

Titanium sulphate was prepared by digesting titanium hydroxide, obtained by hydrolysis of pure titanium tetrachloride, in sulphuric acid. A sample of anatase was prepared by hydrolyzing titanium sulphate solution with ammonia. The precipitate was washed thoroughly till the washings gave no test for sulphate ion. The precipitate was dried at 100°C. Such precipitates were, however, found to contain some sulphate impurity. 

Biryuk L.I., Goroshenko L.G., Khondros E.L., Kalmichenko A.M. Change of composition and structure of titanium hydroxides depending on heating. Ukrainskii Khim. Zhurn. 1971 37 1221-24. 

Numerous publications in the 1960s and 1970s dealt in detail with the description of the mechanism, equilibrium, and kinetics of the uranium sorption reaction on titanium hydroxide [163]. Scaled-up testing of uranium sorption from seawater was carried out in the Soviet Union, United States of America, Great Britain, and Germany. The results were used in the design and construction of units for uranium recovery approximately 10-100 g of uranium were produced per year [180,181]. 

Unsatisfactory physicochemical stability of the sorbent. Titanium hydroxide is slightly soluble in seawater (0.1 mg/1 [165]) and also shows some degradation upon aging. Mixed titanium and zirconium oxide-type sorbents, known as thermoxides with much better stability [178, 179] were developed. 

Peroxotitanium complex [Ti(0H)302], obtained from this reaction, is unstable and decomposes to produce a precipitate of titanium hydroxide (Equation 5.2), even at room temperature ... 

In conclusion, to obtain a stable complex of titanium in aqueous solution, the following four factors should be considered (1) the ligand should contain both a hydroxyl group and carboxyl group (2) the ligand should coordinate titanium in such a way that it forms either a live- or six-member ring (3) the coordination number of titanium must be six or seven (4) the complex should be anionic. With these factors, the attack of Ti by H2O or OH in an aqueous solution is hindered by the steric factor and precipitation of titanium hydroxide is prevented, that is, a stable titanium aqueous solution is obtained. Synthesis of titanium-based ceramics using these aqueous solutions is described in the next section. 

FIGURE 7.6 Spherical nanophased titanium hydroxide particles obtained in SC CO2 from hydrolysis and condensation of tetraisopropyl-orthotitanate at 323 K and 30 MPa. 

Papet S, Sarrade S, Julbe A, and Guizard C. Titanium hydroxide synthesis in supercritical solvent. Sixth Meeting on Supercritical Fluids, Nottingham, England, 1999. 

Loughnan (1969) discussed the solubility in relation to pH of some of the common products of chemical weathering of silicate minerals, In general, the hydroxides of Na, K and Ca are soluble at all pH s, and Mg(OH)2 is soluble at pH < 10. Aluminium oxide is soluble at pH s < 4 and >10, whereeis SiOj is slightly soluble at pH < 9 and increasingly soluble at higher pH values. Titanium hydroxide is soluble at pH < 5, but TiOz is soluble only at pH < 2. The hydroxide of trivalent iron is soluble only below pH 2.5, but Fe(OH)2 is soluble below about pH 8.5. 

Derivation By treating titanium hydroxide with potassium oxalate and oxalic acid. 

Chemistry and Generation. Titanium tetrachloride (CAS No. 7550-45-0), also known as titanic chloride and has the military code of FM, is a colorless liquid of vapor pressure 10.0 mm Hg (20°C Whitehead, 1983), that fumes strongly when exposed to moist air, forming a persistent dense white cloud (Lewis, 1993). The exothermic reaction products are oxychlorides and hydrogen chloride (Ballantyne, 1982) and finally titanium hydroxide and hydrochloric acid (Lee et al., 1986). One dissemination mode is from aircraft for the production of smoke curtains extending down to ground/sea level (RAMC, 2002). 

Peroxytitanium species have been detected during the production of hydrogen peroxide from organic hydroperoxides and Ti(SO)4)2- Alkaline earth peroxy-titanates, e.g. Ca3[Ti(02)4(0H)2]H20, have been prepared by the addition of Ca(N03)2 to a solution of titanium hydroxide in ammoniacal hydrogen peroxide the composition and structures of the compounds were established by thermal analysis i.r. and n.m.r. spectroscopy, and X-ray diffraction, their thermal stabilities decrease in the series Ba > Sr > Ca. 

Low moisture content of fillers are typically observed in calcium carbonate and wollastonite (0.01-0.5%), talc and aluminum trihydrate, mica (0.1-0.6%). Medium moisture content can be observed in titanium hydroxide (to 1.5%), clay (to 3%), kaolin (1-2%), and Biodac (2-3%). High moisture content is often seen in cellulose fiber (5-10%), wood flour (to 12%), and fly ash (to 20%). Biodac absorbs 120% of water under direct contact with an excess of water. 

Titanium hydroxide, 129 Wollastonite, 129 Wood flour, 129 Mold and spores, 412,413 Mold growth, 27, 412-416 Mold propagation, 26,412 16 Mold shrinkage, 105, 131 Nucleation, effect of, 131 Plastic crystalllinity, effect of, 131 Moldable thermoset acrylic polymer, 80 Molecular weight distribution (MWD), 63, 636, 649-651... 

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