- Synthesis of CaCu3Ti4O12, Study of Physicochemical and Photocatalytic Properties
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Abstract: Precursor CaCu3Ti4O12 has been obtained using solution method in acetic acid medium, it was annealed at 100, 200, 400, 600 800, and 1100°C. Sintered powders have been studied by physicochemical methods of analysi
- Ivanov,Alekseeva,Agafonov
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- Synthesis, characterization and the thermal decomposition of calcium(II)bis(oxalato)calcium(II)dihydrate
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Calcium(II)bis(oxalato)calcium(II)dihydrate, Ca[Ca(C2O4)2]·2H2O, has been synthesized and characterized by elemental analysis, and reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG, and DTA) in air showed that the final end product was CaO at 865°C through the intermediate formation of a mixture of CaCO3 and CaO at approx. 818°C. At around 424°C a mixture of CaO and Ca(C2O4)1.2 is formed by partial decomposition of oxalate which is stable up to 670°C. DSC studies up to 700°C in nitrogen at 10°C min-1 showed both endothermic and exothermic peaks with activation energies of 190 and 458 kJ mol-1, respectively, and compared with values calculated from TG. Some of the decomposition products were identified by spectral, analytical and X-ray powder diffraction studies and a tentative mechanism for the decomposition is proposed.
- Deb,Baruah,Dass
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- Dissolution of calcium carbonate in aqueous solutions of acetic acid
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A kinetic equation for the calcium carbonate dissolution, fitting the experimental data to within 8.1%, was obtained. The additional diffusion hindrance caused by the CO2 evolution in the course of the dissolution was considered.
- Blinkova,Eliseev
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- DIRECT CONVERSION OF ESTERS TO CARBOXYLATES
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A calcium carboxylate is prepared by reacting water, calcium oxide, and a compound of formula (I): wherein R is a C1-C3 alkyl and R1 is a C1 or C2 alkyl. The reaction solution is heated to remove an amount of a co-product from the reaction solution. The calcium carboxylate may be recovered in a solid form from the reaction solution.
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Paragraph 0041
(2022/03/22)
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- On the nature of calcium magnesium acetate road deicer
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CMA (calcium magnesium acetate) road deicers have gained popularity in recent years as an environmentally friendly alternative to traditional rock salt, and as an industrial adsorbent for removing H2S and other odorous acid gases from gas streams. Despite its increasing commercial use, its exact composition and crystalline structure remained unknown, with subsequent problems in evaluating properties of commercial CMA. Various synthetic routes towards formation of crystalline calcium magnesium acetates were investigated. From aqueous solutions preferential formation of calcium monohydrates or calcium monohydrate acetic acid solvates is observed. Crystals of genuine mixed metal calcium-magnesium acetate were obtained from hot glacial acetic acid. Material suitable for analysis by single crystal X-ray diffraction, SC-XRD, was obtained by slight reduction of solvent volume at 80 °C for several hours. CMA crystallizes in the orthorhombic space group Pnma with a formula of Mg2Ca(OAc)6 (OAc = acetate anion), with a magnesium to calcium ratio of two to one. Under the same conditions, but in the absence of magnesium, the acetic acid solvate of calcium acetate, Ca(OAc)2(HOAc), is obtained, which is also described. Multicrystalline XRD and EDS analysis data of ground CMA samples match those of commercial CMA. Single crystal structural analysis finds an unusually large unoccupied void space of 9.4% of the unit cell volume. Thermal gravimetric analysis, TGA, gives an upper limit of one water molecule per formula unit of CMA, leaving the void space at least partially unoccupied. This helps to better understand CMAs unusually low density, which had been an issue when used as a commercial road deicer, having been described as being easily blown off road surfaces when applied in crystalline or powder form.
- Miller, Jennifer R.,LaLama, Matthew J.,Kusnic, Rachel L.,Wilson, Darian E.,Kiraly, Paije M.,Dickson, Samuel W.,Zeller, Matthias
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- RECOVERY OF ORGANIC ACID USING A COMPLEX EXTRACTION SOLVENT
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A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. An amine, C02 and a water immiscible solvent are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and the amine that is soluble in both an aqueous and a solvent phase. The complex is extracted into the solvent phase which is than distilled to recover the acid or an ester of the acid in a concentrated form.
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Page/Page column 34-35
(2012/05/05)
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- CALCIUM ABSORPTION ENHANCER
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The present invention provides a calcium absorption enhancer that places no burden on the body of a human or a domestic animal to which a calcium compound is administered and can increase the efficiency with which a calcium content is absorbed into the body by supplying calcium ions in the stomach or the like of the human or the domestic animal in a sustained-release manner after administration of the calcium compound. The calcium absorption enhancer of the present invention contains, as an active ingredient, water-soluble calcium particles that can release calcium ions in an aqueous solution in a sustained-release manner.
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- Preservative and Additive for Food and Feed
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A preservative and additive for food and feed. One aspect of the invention concerns various acidified clays and minerals as food or feed additive to kill, or inhibit the growth of, harmful microorganisms and to inactivate mycotoxins, such as aflatoxins, present as contaminants in human foods and animal feeds. Another aspect of the present invention relates to a clay of hydrated sodium calcium aluminosilicate with relatively uniform particle size distribution.
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- Precursors for mixed metal oxide nanoparticles: Synthesis and characterization of μ-oxoalkoxides of some bivalent metals and their β-diketonates
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New heterobimetallic derivatives of the type M{OAl(OPri) 2}2 (M = Sn, Pb, Cd) have been prepared by the reactions of M(OAc)2 with Al(OPri)3 in 1:2 molar ratio in hydrocarbon solvent (xylene/toluene) with the continuous liberation of isopropyl acetate. Furthermore, reactions of M{OAl(OPri) 2}2 (M = Ca, Pb, Cd) with β-diketones (acetylacetone, benzoyl acetone) have also been carried out to obtain modified derivatives. These new derivatives have been characterized by elemental analyses and spectroscopic [IR, NMR (1H, 13C, 27Al and 119Sn)] studies.
- Sharma, Malti,Bhagi, Ajay K.,Sharma, Harish K.,Priti, Ritu Kansal,Kumar, Ram,Kapoor, Pramesh N.
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p. 256 - 260
(2007/10/03)
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- Highly acidic metalated organic acid
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A highly acidic metalated organic acid composition and its preparation. The acidic composition can be prepared by mixing a monovalent or polyvalent cation and an organic acid in the presence of a strong oxyacid, wherein the resultant acidic composition is less corrosive to a ferrous metal than a solution of a mineral acid having the same acidic pH value as that of the acidic composition, and where in the acid composition is more biocidal than a mixture of the organic acid and a metal salt of the organic acid which mixture has the same acid normality value as that of the acidic composition. The acidic composition can be prepared by mixing at least one regenerating acid, at least one metal base, and at least one organic acid, wherein the amount of the regenerating acid is in excess of the equivalent amount of the metal base.
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Page/Page column 10
(2008/06/13)
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- Pharmaceutical composition containing calcium acetate and calcium carbonate
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A pharmaceutical composition useful for the treatment of hyperphosphatemia, in particular for decreasing the high blood concentration of phosphate which is present in uremic patients or in patients with chronic renal failure.
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- A METHOD OF MAKING SALT
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A method of making the salt of an acid, includes the steps of combining and mixing the acid and a base selected from the oxides, hydroxides and carbonates of sodium, potassium, calcium and magnesium, in a first reaction zone over a first period to produce a reaction mixture. The reaction mixture is transferred at the end of the first period from the first reaction zone to a second reaction zone the transferring step being carried out over a second period. Heat generated by reaction between the acid and the base in the second reaction zone drives off sufficient water to produce a product mixture containing less than about 8 % (m/m) water. The first period is between about 1 and 180 seconds and the second period is between about 2 and 60 seconds.
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Page/Page column 17
(2008/06/13)
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- Preparation of Bi-based high-Tc superconducting films from methacrylate solutions
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Bi2Sr2CaCu2Ox superconducting films containing minor amounts of Bi2Sr2Ca2Cu3Ox were prepared by spray pyrolysis of methacrylate solutions on LaAlO3 substrates. The best superconducting properties (Tc ? 80 K, ΔTc ? 10 K) were shown by the films annealed at 850°C, which consisted mainly of platelike crystallites with a high degree of [001] orientation. The composition, content, and morphology of the calcium strontium cuprates and oxides present as impurity phases were found to correlate with the annealing temperature and film thickness.
- Men'shikh,Geras'kina,Prutchenko,Rybakova,Tomashpol'skii
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p. 517 - 520
(2008/10/08)
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- Method of producing calcium salts from biomass
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Calcium salts, such as calcium acetate, calcium formate or calcium proprionate, are obtained from aqueous liquors derived from the pyrolysis of lignocellulosic biomass containing cellulose, hemicelluloses or starch. The above biomass is subjected to rapid pyrolysis to obtain a crude product containing an aqueous phase and an organic phase. The product obtained, preferably as the aqueous phase, is then distilled to produce a distillate containing at least one acid selected from acetic acid, formic acid and propionic acid as well as their esters and formaldehyde. An alkaline source of calcium is added to this distillate to adjust the pH to an alkaline level sufficient to hydrolyze the esters, cause at least partial oxidation of the formaldehyde and prevent volatilization of acetate, formate or propionate ions as acetic acid, formic acid or propionic acid respectively. This pH adjusted alkaline liquid is then subjected to a further distillation to remove water and volatile organic components and produce at least one of calcium acetate, calcium formate and calcium propionate as solid residue.
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- Process of preparing an amino thiazolyl disulfide using a water soluble salt in combination with wet 2,2-dithiobis(benzothiazole)
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In a known process for preparing 2-(4-morpholinodithio)-benzothiazole using 2,2'-dithiobis(benzothiazole) along with morpholine, sulfur, an inert organic solvent such as isopropyl alcohol and an oxidizing agent, the improvement wherein a water soluble salt in combination with wet 2,2'-dithiobis(benzothiazole) is substituted for dry 2,2'-dithiobis(benzothiazole).
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