Calcium titanates

KEYWORDS barium titanate, calcium incorporation, XPS Conesponding author e-mail mcchang ks.kunsan.ac.kr... 

Compounds that have been proposed to react by this mechanism include barium titanate, calcium titanate, calcium carbonate, strontium titanate and magnesium oxides[8,9,10]. All these basic compounds should theoretically react with vanadic acid and bind it in the trap and have proved effective in laboratory evaluations. However, sulfur competition negatively affects the performance of these traps in commercial units[8,l 1],... 

Calcium titanate Calcium titanium oxide (CaTiOs) Calcium titanium trioxide EINECS 234-988-1 RC17 Titanate (Ti03 ), calcium (1 1) Perovskite Titanium calcium oxide. Inorganic compound used in electronic devices. Atomergic Chemefa/s Cerac f oflranselco Tam Ceramics. 

Calcium titanate trioxide Calcium titanium trioxide. See Calcium titanate Calcium trisodium diethylene triamine pentaacetate. See Calcium trisodium pentetate Calcium trisodium pentetate CAS 12111-24-9... 

A variety of other nanoparticles have been formed by such in situ sol-gel reactions. Examples are the oxides of titanium, aluminum, - tanta-lum, zirconium, niobium, and vanadium. Some nanocomposites of this type have also included barium titanate, calcium oxide, calcium salts, borates, HTiNbOg, and Eu dopants. ... 

Additives used in final products Fillers barium titanate, calcium carbonate, carbon black, carbon black coated with conductive polymer, copper powder, hafnium powder, lead zirconium titanate, silica, tantalum powder, titanium dioxide, zeolite, zinc sulfide plasticizers adipic polyester, dibutyl phthalate, dibutyl sebacate, glyceryl tributyl-ate, tricresyl phosphate Antistatics carbon black, glycerol monooleate ... 

Gubkin and Skanavi [6S] prepared stable ceramic ciectrets from various titanate materials, such as strontium-bismulb titanate, barium titaiute, strontium titanate, calcium titaiute, etc. They showed that ceramic electrets retain the majority of their charge without the need of shorting them with metal fbilt. Thomas A. Dickinson (66,67) showed... 

There are several publications [4—16] on admixtures of barium sulfate, aluminium fluoride, aluminium borate, aluminium titanate, calcium silicate (woUastonite), aluminium nitride, and silicon carbide and its combinations in alumina silica refractories for decreasing the wetting ability of Al in these refractories. 

Other. Insoluble alkaline-earth metal and heavy metal stannates are prepared by the metathetic reaction of a soluble salt of the metal with a soluble alkah—metal stannate. They are used as additives to ceramic dielectric bodies (32). The use of bismuth stannate [12777-45-6] Bi2(Sn02)3 5H20, with barium titanate produces a ceramic capacitor body of uniform dielectric constant over a substantial temperature range (33). Ceramic and dielectric properties of individual stannates are given in Reference 34. Other typical commercially available stannates are barium stannate [12009-18-6] BaSnO calcium stannate [12013 6-6] CaSnO magnesium stannate [12032-29-0], MgSnO and strontium stannate [12143-34-9], SrSnO. ... 

The resultant slag, a complex mixture of titanates, may contain 70—85% Ti02- The slag route is particularly useful when ilmenite is closely associated with haematite, from which it cannot economically be separated mechanically. Because the iron content of the slag is low, its use reduces the quantity of iron sulfate in the Hquid effluent of sulfate process plants. Slag used as a feedstock for TiCl production must be low in magnesium and calcium. A variety of other ilmenite beneficiation or synthetic mtile processes have been pursued, primarily to provide alternative chloride process feedstocks. Low grade ilmenite... 

Fluor-jod, n. iodine fluoride, -kalium, n. potassium fluoride, -kalzium, n. calcium fluoride, -kiesel, m. silicon fluoride, -kie-selsaure,/. fluosilicic acid, -kohlenstoff, m. carbon fluoride, -lithium, n. lithium fluoride. -metall, n. metallic fluoride, -natrium, n. sodium fluoride, -phosphat, n. fluophosphate. -phosphor, m. phosphorus fluoride, -salz, n. fluoride, -schwefel, m. sulfur fluoride, -selen, n. selenium fluoride, -silber, n. silver fluoride, -silikat, n. fluo-silicate. -silizium, n. silicon fluoride, -sili-ziumverbindung, /. fluosilicate. -tantal-sMure, /. fluotantalic acid, -tellur, n. tellurium fluoride, -titan, n. titanium fluoride, -toluol, n. fluorotoluene, fluotoluene. 

For silica fillers, hydrolytic stability is best when M = Si for other fillers, e.g., calcium carbonate then titanate- or zirconate-coupling agents are preferred. 

Various investigations have considered the effects of titanate treatments on melt rheology of filled thermoplastics [17,41]. Figure 10, for example, shows that with polypropylene filled with 50% by weight of calcium carbonate, the inclusion of isopropyl triisostearoyl titanate dispersion aid decreases melt viscosity but increases first normal stress difference. This suggests that the shear flow of the polymer is promoted by the presence of titanate treatment, and is consistent with the view that these additives provide ineffective coupling between filler particles and polymer matrix [42]. 

Fig. 10. Viscosity and first normal stress difference vs. shear stress for polypropylene (at 200 °C) filled with calcium carbonate (50 wt%) with and without a titanate coupling agent (TTS ) (O, ) pure polypropylene (PP) (A,A) PP/CaC03=50 50 (by wt.) ( , ) PP/CaC03=50 50 with TTS (1 wt%). The open symbols were obtained from a cone and plate instrument and the closed symbols from a slit/capillary rheometer.

Octammino- titanic Chloride, [Ti(NH3)8]Cl4, is obtained by passing dry ammonia gas into a suspension of titanic chloride in ether ammonia is rapidly absorbed, and a dark yellow powder formed of composition TiCl4.8NH3. The substance loses ammonia very readily, and is immediately decomposed by moist air, but not if kept over freshly prepared anhydrous calcium chloride. 

Hexammino-titanic Chloride, [Ti(NH3)6]Cl4, is prepared by allowing a stream of dry hydrogen saturated with gaseous titanic chloride to come in contact with dry ammonia gas in a specially designed flask. A voluminous yellow powder remains, which is unaltered in dry air, and does not lose its yellow colour over freshly ignited calcium chloride in absence of air. Water decomposes the substance, with formation of titanic acid and ammonium chloride thus ... 

Rosenheim described a tetrammino-derivative, TiCl NHj, which he obtained by allowing the product from the action of dry ammonia on an ethereal suspension of titanic chloride to stand over dry calcium chloride. The substance so obtained was white, but further examination proved it to be a mixture of titanic acid and ammonium chloride produced by moisture in the air and in the imperfectly dried calcium chloride. 

Electroceramics. Titanates like barium, strontium, calcium and lead titanate prepared from finely divided, high-purity TiOz hydrolysates are used in capacitors, PTC-resistors and piezoelectric materials. The specifications of the Ti02 starting materials with respect to purity, reactivity, and sintering properties are expected to become more stringent. The market is estimated to be several thousand of tonnes a year as TiOz. A strong annual growth is expected. 

PEROVSKITE. The mineral perovskite is calcium titanate, essentially CaTiCL, with rare earths, principally cerium, proxying for Ca, as do both ferrous iron and sodium, and with colunibiuni substituting for titanium, ll crystallizes in die orthorhombic system, but witli pseudo-isometric character fracture subconchoidal to uneven brittle hardness, 5.5 specific gravity. 4 luster, adamantine color, various shades of yellow to reddish-brown or nearly black transparent to opaque. It is found associated with chlorite or serpentine rocks occurring in the Urals, Baden, Switzerland, and Italy, It was named for Von Perovski. 

MacNevin and Ogle (87) investigated the effects of impurities on the photochromism of barium and calcium titanates as shown in Table V. Pure samples of barium and calcium titanate were not photochromic and doping with Ag+1, Cu+2, Sb+3, Sn+4, Zn+4, and Co+2 produced no enhancement of photochromism. However, increases in the concentrations of impurities such as Fe+3, Zn+2, Sb+5, and V+6 promote photochromic activity. MacNevin and Ogle concluded that the photochromism in these systems depends on the insertion into the lattice of an impurity ion having, (a) an ionic radius near that of Ti+4, and (b) an oxidation number other than 4 to make electron transfer possible. 

Salts of these elements, on treatment with soda, yield no precipitate, for they are dissolved by the alkali the compounds formed are indefinite, but it may be supposed that they contain aurate, MAuOg.Aq, or platinate, titanate, zirconate, or thorate, MPtOg.Aq, c. Iron and calcium titanates occur native FeTiOg is termed ilmenite, and CaTiOg perowskite. The first is isomorphous with and crystallises along with native ferric oxide the ore is known as titanic iron ore. It is the commonest compound of titanium. 

Actually, during the reactions, the meta-titanic acid H2Ti03 is precipitated first, which adsorbs considerably large amounts of water and soluble impurities such as ammonium sulfate, ammonium chloride etc, and also contains some insoluble impurity particles such as oxides of iron, strontium, and calcium etc. Therefore, it is essential to fully wash the precipitate to obtain a product of high purity. The insoluble and part of the soluble impurities can be removed by multiple washings ammonium chloride and ammonium sulfate are decomposed and released as the precipitate is later heated to 300°C and 700°C, respectively, during the calcination. 

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