Titanate powders

Table 2. Commercial Hydrothermal Barium Titanate Powders ...

Barium titanate thin films can be deposited on various substances by treating with an aqueous solution containing barium salts and an alkanolamine-modifted titanate such as TYZOR TE (151). In a similar fashion, reaction of a tetraalkyl titanate with an alkah metal hydroxide, such as potassium hydroxide, gives oxyalkoxide derivatives (KTi O(OR) ), which can be further processed to give alkali metal titanate powders, films, and fibers (152—155). The fibers can be used as adsorbents for radioactive metals such as cesium, strontium, and uranium (156). 

PZT (lead zirconate titanate) and PLZT (lead lanthanum zirconate titanate). Powder of these materials produced by CVD are being investigated. 

Fine chemicals These are produced in small volumes and purchased on the basis of chemical composition, purity and price. Examples are chloropropylene oxide (used for the manufacture of epoxy resins, ion-exchange resins and other products), dimethyl formamide (used, for example, as a solvent, reaction medium and intermediate in the manufacture of pharmaceuticals), n-butyric acid (used in beverages, flavorings, fragrances and other products) and barium titanate powder (used for the manufacture of electronic capacitors). 

There are four principal routes to producing barium titanate powders. 

THE PRODUCTION OF HYDRIDES IN TITANIC POWDERS UNDER DIFFERENT WAYS OF MANUFACTURING... 

Abstract. Diffusion of gases in titanic powders depends on a way of manufacture, the conditions of lixiviation at hydrometallurgical processing of powders, and also on a condition and on the structure of the surface of particles. The different methods to investigate products of corrosion, as on a surface of particles, and in the fulfilled solutions in which the tests are performed, are given. The correlation between them is established. The influence of oxygen on formation of hydrides is shown. The recommendation for use titanic powders saturated by gas is given. 

Keywords titanic powders, diffusion of hydrogen and oxygen, oxides, hydrides in titanic... 

From the literature it is known [I, 2, 4] that the stability in aggressive environment is naturally connected with the structure and condition of titanium. Therefore, performing the corrosion tests has allowed deeper understand a nature of gas saturation of titanic powders of different kinds of manufacturing, and to obtain new results. 

Figure 1. Formation of oxyhydride film on particles of titanic powders, x300.

Figure 2. Structure of a surface particles of titanic powders saturated by gas, x300.

With the increase of hardness of titanic powder the similar processes accelerate, and after 100 hrs of exposure hydrides of titanium occur along the strictly parallel strips of sliding, which also have the certain strict crystal orientation under an angle 120 and 60 degrees. 

Figure 5. Mutual influence of oxygen and hydrogen on hardness of electrolytic titanic powders.

Practically all titanic powders with a different degree of impurity can be recommended as a filling compound for corrosion resistant materials which work in muriatic environments. 

Shapovalova O.M., Babenko E.P., Babenko J.V. Influence of hydrogen on structure and property of titanic powders // VII International Conference "Hydrogen materials science and chemistry of metal hydrides". - Ukraine. -2001. 

To optimize the use of the amorphous sodium titanate powders as catalyst substrates, it is important to fully characterize the ion-exchange properties of the material. Further, the solution properties of the active metal to be loaded onto the support will be an important parameter in the control of the adsorption process. For example, exposure of sodium titanate to a nickel salt solution does not guarantee that nickel will be loaded onto the sodium titanate, or that the nickel, if loaded, will be dispersed on an atomic level. Sodium titanate only behaves as a cation exchange material under certain pH conditions. The solution pH also influences the hydrolysis and speciation of dissolved nickel ions (3), which can form large polymeric clusters or colloidal particles which are not adsorbed by the sodium titanate via a simple ion-exchange process. 

This paper describes some of our initial studies of the solution properties of sodium titanate powders in order to understand and control the metal-loading process in the preparation of a heterogeneous catalyst from the materials. The purposes of this study are 1) to define the pH and concentration regimes in which nickel is loaded onto sodium titanate as monomeric ions via ion exchange, as polymeric clusters via hydrolysis, or as discrete particles of colloidal nickel hydroxide, and 2) to characterize the catalysts with respect to the dispersion of the active metal under reaction conditions by measuring the activity and selectivity of the catalysts for a known "structure-sensitive" reaction, the hydrogenolysis of n-butane. 

Three different nickel-loaded sodium titanates were prepared by exposing 5 gm of the sodium titanate powder to aqueous solutions of nickel nitrate containing sufficient nickel to incorporate one mole of nickel for every two moles of sodium on the support (corresponding to the stoichiometry associated with complete ion exchange). Each sample was prepared using different pH conditions (and thus, different Ni(II) concentrations) to vary the mechanism of... 

Titanic powders obtained in different ways have structure a-Ti, which has two... 

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